#883 - Dr Matthew Walker - The Science Of Perfect Sleep

You might be the British man with the best hair that I know. I think it is the greatest cry of a midlife crisis that you are ever going to see.
It's a total train wreck. I'm suggesting that no one told me the pandemic was over and that you can get your hair cut.
This is the consequence of it. So for anyone who is watching, any therapy bills that you have to have after seeing me and being fronted by me send them to me i will pay for them oh my goodness fantastic well uh what a good opening it is it is it is what it is um talking about sleep today we had a lot of conversations about it on the show previously but i really want to dig into some sort of more rare insights that people probably know that they need to know but don't yet yet know.
So just to get started, how do you come to think about what good sleep is? How do we conceptualize good sleep? Yeah, it's an interesting question because I think everyone, most mornings, let's say you've got a significant other, you come down the stairs and you say, you know, how do you sleep? And I'll say, I slept well, or I didn't sleep well. So everyone themselves has a subjective estimate of what this thing called good versus bad sleep is.
Science is a little different though. And medicine teaches us that there are essentially what I would describe as the four macros of good sleep.
And so three macros of food, fat, carbohydrate, and protein, four of sleep. And you can remember it by the acronym QQRT, quantity, quality, regularity, timing.
And there's all sorts of stuff on the internet about, you know, take this supplement, do this particular thing. And it's the Shangri-La of all good sleep.
And you'll have this utopian blissful night. Honestly, if you just focus on these four main principles, you're 80% of the way there.
So quantity is what we used to espouse in sleep as the measure of good sleep, which is somewhere between seven to nine hours for the average adult. And there is variability.
The next one is quality. And I think this is probably- Actually, I need to jump in on the quantity before you even move on.
Yeah. Quantity of sleep, time in bed, time asleep.
Astute question. Most of us conflate the former for the latter and it's potentially dangerous.
So if you are a good sleeper, you will have what we call a sleep efficiency of at least 85%, which means, so sleep efficiency of the time that you're in bed, what percent of that time are you asleep? And really good sleepers will have, let's say, 80 to 90% sleep efficiency. So even if you're in bed for seven hours, you're not getting seven hours of sleep.
Looking at close to six. Correct.
So to get at least the minimum, according to the CDC of seven hours, you actually have to be on average in bed, maybe about eight, eight hours and 15 minutes. So it's a really astute point that we sort of misconstrue the question of total sleep duration as total time in bed, and you have to subtract one from the other.
And that's why I think there is some legitimacy in looking at, say, sleep tracking data, because at least that will tell you total sleep time. I mean, that was the- Absent of, you know.
Exactly. That was the biggest realization.
I looked at my end of year review for whoop and um i've worn this thing for 1600 nights since way before they were a partner on the show and uh the biggest realization i've said i think whoop's great and you can sign up for it if you want but i can tell you what the realization is the main realization that you're all going to come to which is eight hours in bed does not mean eight hours of sleep that's the biggest realization everybody comes Everybody comes away from it. Well, I was sure I was in bed for eight.
I thought I got eight hours. And he goes, well, it told me that I was actually only in bed for seven and a half.
And I kind of had a bit of a bad night. So I had like six, 15 of sleep last night.
I thought I was in bed for eight. You go, that's a red pill that everybody needs to take.
Yeah. So I think it's one of those areas that is not highlighted enough.
And that's why you can actually then come on to the second of the cues, which is quality. And that in fact is efficiency, sleep efficiency.
Well, there's two ways we measure quality. The first is sleep efficiency.
So as I said, I want to see you at least asleep 85 to 90% of the time that you're in bed. If you are staying in bed, let's say for nine hours and your sleep efficiency is 70, maybe 65, then my recommendation is perhaps surprising.
Do not get into bed that early and do not stay in bed that late. I want to cinch you down to maybe even just six and a half hours of time in bed.
And we've already said, well, hang on a second, six and a half hours of time in bed is too little to get seven hours of sleep by the mathematics, even maybe six. But what I'm going to do by way of constraining your bedtime there is force efficiency out of your system.
I go to the gym, I'm there for an hour. I start working out.
I do the 11th rep, pull out my phone. I'm there looking at Twitter, you know, looking at Chris Williamson's content.
And then, you know, I'm chatting to people. I'm not efficient.
And maybe I am only working out for 30 minutes. Next day, someone comes in two bouncers on the door.
You've only got 25 minutes in the gym. First couple of days, I'm just as lazy and I get maybe 40% of my workout done and I get ejected.
By day three or four, the pressure that's built up for me to want to exercise and get it all in is so high that I go into the gym, my phone's down, on the counter, I speak to no one and I blast through my workout and I get it done. It's the same with sleep.
I build up night after night, this increasing hunger where your system was lazy before it had inefficiency. And after a while, it's essentially like hitting the reset button on your wifi router.
I retrain your brain to realize I don't have eight and a half, nine hours of time in bed anymore to be lazy. He's only giving me six and a half hours.
I've got to get busy. And all of a sudden you've got 95% sleep efficiency because as soon as you get into bed, you are asleep and you sleep almost through the night.
Then gradually I will step you back out. If you start to get lazy again, we stitch you back up again.
And gradually that's how we retrain the system. What about the reverse when it comes to sleep quality that somebody is staying in bed for a good amount of time, but that quality doesn't seem to want to change.
Cinching it down doesn't really seem to make that much of a difference. They're just waking up too much throughout the evening.
They're not hitting REM. They're staying quite light.
They're getting up earlier than they want to, et cetera, et cetera. Yeah.
At that point, we've got to then start to ask if we've driven enough pressure in the system, what we call sleep pressure or sleep debt, and you are still waking up throughout the night. First, medical conditions.
Let's do blood work. Let's see if you're suffering from a sleep disorder like sleep apnea, restless leg syndrome.
If we exclude all of those that you're medically healthy, then we have to ask, what are you doing in your life? Exogenous components, principally, caffeine, alcohol, light. And the principal one that we don't talk about is stress and anxiety.
If there is a principle reason why most people in society, absent sleep disorders are not sleeping well, it's because of this wired but tired phenomenon. We have people come to my sleep center all the time and they say, I am just so tired.
I'm so tired, but I'm just so wired that I can't fall asleep or stay asleep. So at that point, when we've built up all of that pressure forced you to be efficient and you haven't been efficient, we exclude you medically that you're healthy, no sleep disorders.
Then we've got to figure out what's going on in your life. Let's dig into that wide but tired stress thing.
What is going on in the body from a sleep perspective in the body and the brain when you're in a high stress lifestyle? Yeah, there's probably at least two things going on in the body and at least one thing going up in the brain. The first in the body is the balance between the two branches of your nervous system.
One is the fight or flight branch called the sympathetic nervous system. It's very poorly named.
It's anything but sympathetic. It's very agitating and activating.
And then there's the parasympathetic. That's the kind of quiescent branch of your nervous system.
If you're a good, healthy sleeper and you don't have too much stress in your life, you naturally switch over to that restful, quiescent branch of the nervous system. And that is the royal kind of pathway to good sleep.
And the alacrity of sleep, the speed with which sleep arrives to you when you disengage from the fight or flight branch is really speedy and rather beautiful. If you are so wired though, however, the sympathetic, the fight or flight branch is activated.
Your heart rate is jacked. Your blood pressure is too high.
Your temperature, because of that activated state, your core body temperature is also too high. If you are too hot, your heart is racing and your blood pressure is high.
it's very difficult for you to fall asleep. At the top of that, a second system in the body, which is what we call the HPA axis or the, it's essentially the stress axis, which descends down from a brainstem area, the hypothalamus down to the pituitary releases adrenaline.
All of a sudden you are cortisol flooded. And I think everyone has had that sense where, whether it's, let's say you've been on stage, you've been on tour, you come off stage and you are wired.
Now this is not you're anxious, but you're still wired. Cortisol is streaming.
Your heart rate is jacked. And you can say, I was up at seven this morning and it's now two o'clock because all is said and done.
I am still unable to fall asleep. I'm so tired, but I am way too cortisol, you know, sort of concentrated.
Yeah, exactly. So those two things in the body are what we will presumably, I think most people will cleave to as the ingredients to the type of wide phenomena.
I also think upstairs, and they are interrelated upstairs in the brain, you start to get this Rolodex of anxiety. And I think we've all had that where we're stressed.
In the modern world, we're constantly on reception. Very rarely do we do reflection.
And now the only time based on modernity and how it inflects us that we do reflection is when our head hits the pillow at night. That's the worst time to do reflection.
Because when you start to have that kind of wheel of anxiety whirring, you begin to ruminate. When you ruminate, you catastrophize.
Everything seems twice as bad in the dark of night versus the light of day. And at that point, you're dead in the water for the next two hours.
And that will then only feed in to jacking up the fight or flight branch because you're kind of going through what didn't I do today? What should I have done? What do I need to do tomorrow? I forgot to do that thing that's critical for next week. It's a mental sort of, you know, train wreck in terms of your sleep that then just further perpetuates those two downstream physiological mal sort of consequences.
and then they ramp up and that leads to more. Yeah.
Talk to me about interventions for those three. So the principle one is that you've got to process that.
And this is the hard part of the equation. Mental health work is tough work.
You can take medications and that can be one path for people. You can take certain medications that can try to lower your heart rate, shift you back over into that quiescent state.
But most people don't want to reach for a pill immediately necessarily. One thing you can do is just catharsis.
Two or three hours before bed, not right before bed, pad of paper and a pen, and just write down. I just want you to vomit out all of your stresses and anxieties.
And it turns out that simply doing that will decrease the time it takes you to fall asleep by 50% from zero. Yeah, it's a great study, Michael Scullin.
Fantastic work. So the first thing is just get it all out of you so it's not inside of you.
That said, you can still be burdened with this egregious kind of stress and anxiety nevertheless. So what do you do about that? At that moment in time, whether it's you falling asleep or you've woken up at 3 a.m.
and it's happening and you need to get back to sleep. At that point, let's get your mind off itself.
That is the goal. How do you do that? Maybe at least four things.
First, meditation. The data is really strong.
Now, I was researching this for a book and I just thought, look, I'm a hard-nosed scientist. I'm here at UC Berkeley, San Francisco.
It's all a bit woo-woo, this meditation thing. I'm sort of holding hands and people are strumming guitars at the end of the day.
What is going on? I don't believe this. Studies were so powerful though.
So I thought, I best bloody try some of this myself. And that was six years ago.
And I now meditate for 10 minutes every night before bed.

So the first is meditation, but people just may not feel particularly compelled towards meditation.

No problem. Next one is breath work.
And you can do, you can just Google different types of breath,

you know, box breathing, sort of, you know, three, seven, four, there's all sorts of different

patterns, but that breathing can also just try to bring the nervous system back down into that

Thank you. breathing, sort of, you know, three, seven, four, there's all sorts of different patterns.
But that breathing can also just try to bring the nervous system back down into that zone of sleep permission versus sleep prevention when it's too high. If that isn't your thing, you can do a body scan.
So just close your eyes, start at the top of your head and just start to relax back, feel your neck, feel how tense it is, start to relax it. Maybe even your forehead is that tense and just move through the rest of the body.
Go all the way down through your arms, through your chest, your back, and just, you're not making any judgments. You're just being aware of your body.
That's fantastic too. The final thing, if none of those appeal, mental walk in hyper detail.
So detail so think about let's say a walk that you do with your dog and what i want you to do is think about this at the level of okay i open the drawer which leash am i going to take the blue or the red i'll take the blue one clip the dog in with my right hand i'm closing the drawer with my left open the front door with the left i go down the stairs i look across there's that weird ber house. It's kind of just a little bit hippie, but no problem.
And then the cars always come too quickly around that. But that's the level of hyper detail.
And what's interesting, if you look across all four of the things I've just described, the commonality is that they all get your mind off itself. Meditation, you're starting to focus on something other than your mind.

If you're doing box breathing,

you're all of a sudden body-centric, not mind-centric.

If you're starting to do some type of body scan,

again, it's hard for you to think about your worries and your stresses if you're doing it.

Mental walk, same thing.

Because sleep at that time of night

is a little bit like trying to remember someone's name.

The harder you try, the further you push it away.

Sleep is something that happens to us.

It's not something that we make happen.

And when you get that mind distracted away from itself,

the next thing you typically remember

is the alarm going off in the morning. Why? Because you got your mind off itself.
Okay. So first one, quantity.
Second one, quality, that being a component of that. Is there anything else to say on quality before we move on? Yeah, probably.
The other way that we measure, and most people can't do this, but is in the sleep laboratory, we place electrodes on your head. You look like a spaghetti monster.
And the other way we measure quality is the depth of your deep non-REM sleep. So we have two main types of sleep, REM and non-REM.
Non-REM, for most sleep trackers, you divide it into light non-REM and deep non-REM. Deep non-REM is where you get these incredible, deep, powerful, slow brainwaves that just epic.
And the depth, the size of those brainwaves and how dense they are, the number of them that you're having is another great measure of the quality, the electrophysiological quality of your sleep versus the, are you waking up lots throughout the night and therefore you're spending a lot of time awake, that sleep efficiency, that's another measure of quality. So they're sort of orthogonal, but both bleed into this kind of second silo of sleep quality.
So QQ, next one is regularity, going to bed at the same time, waking up at the same time. and you think this sounds fairly rudimentary and basic.
Part of the reason is because you have a 24-hour master clock in your brain, and that clock thrives under conditions of regularity. And when you feed it signals of regularity, like going to bed and waking up at the same time, it improves both the quantity and the quality of your sleep.
That's what I used to preach as why it was important. Until there was a great study published probably two and a half years ago.
And it was, I think, over 300,000 individuals that they tracked with sleep assessments over a good period of time. And then they looked at them across a much longer lifespan period of time.
And they looked at mortality risk. And they also looked at different forms of mortality risk, cancer mortality risk, cardiovascular disease mortality risk.
And they measured sleep quantity. Sure enough, just like we've seen in many other studies, using that sweet spot of seven to nine hours, the shorter your sleep, the shorter your life.
Short sleep predicted all cause mortality. That's the quantity measure.
They looked at regularity. Regularity demonstrated the same thing.
Those who were in the lowest quartile, those who are least regular, highly erratic, they had far higher rates of mortality relative to the people who were in the top quartile who were incredibly regular. How did that compare to the quantity in terms of predictive power? Genius.
And that was the brilliance of the study that really made me double down on regularity. Because then what they did, they said, well, if we've got these two measures quantity and regularity let's not

look at them individually let's put them in the same statistical model and do a coke pepsi challenge between the two and all of us in the sleep field you know you're betting that quantity is going to be the more powerful statistical variable wasn't regularity beat out quantity in predicting all-cause mortality,

cancer mortality, cardiovascular mortality. Now, it's not to say that you can get away with short quantity of sleep, even if you're highly regular.
Getting four hours of sleep at the same time every night, you still have markedly elevated mortality risk. But nevertheless, I was pretty stunned by how powerful that was and made me even someone who was pretty regular before get a bit more evangelical about it.
You know, we'll get back to talking to Matthew in one minute. But first, I need to tell you about mantis sleep.
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How big of a wobble are we talking in terms of tolerance here? People can't just go to sleep at the same time, the same minute, every single night. What's an acceptable tolerance window for swings? And is there a difference for going to sleep time versus waking up time? How can people navigate this regularity landscape? Yeah, beautifully put.
So it's a two by two, you know, is it offset versus onset of sleep, getting into bed, get out, which is the more powerful? Right now, we don't know which one you should keep as more regular. We haven't been able to dissect that yet.
However, to your question, what's the amount of wiggle room? I'm describing here in terms of the four macros, this ideal world of good sleep. And it turns out, drum roll, none of us live in the ideal world.
We all live in this thing called the real world. So just for goodness sake, stop being so puritanical.
It turns out that you've got a wiggle room of about 15 to 20 minutes on either side of it. So there is some degree of play in the system.
Not much. But not too much.
And this is to not have sleep regularity have a negative impact on your mortality outcomes? Is that the measure that we're looking at? Correct. Or just your mortality in terms of cancer or your mortality in terms of cardiovascular disease or all of the mortality buckets thrown together into a big old mix.
Presumably including car accidents and all manner of other things that can occur. Correct.
By way of microsleeps and all of that, you know, that's the way that a lack of sleep will pop you out the gene pool, you know, very quickly rather than chronically through disease and sickness. Okay.
So talk to me, you know, people might not be able to work out what the different quartiles would be. If 15 to 20 minutes of wiggle room for both going to sleep and waking up, I would actually guess that most people, more people in terms of regularity will have their wake time versus their sleep time in that most people have a thing that they need to do.
Correct. the alarm goes off and whether you like it or not

you are up for many people yeah the same isn't true when you go to sleep so i'm going to imagine that there's more wobble on the bottom end yeah less wobble on the top end uh but talk to me about what's the upper quartile and what what are we looking at here how how uh deep does the trough go of swings.

Yeah.

The highly irregular people were somewhere between two to two and a half hours variable. So in other words, they may have an offset of going to bed or waking up or just some wiggle room of an hour, you know, one side of their mean and then an hour the other side of the mean.
So again, it doesn't sound like too like too much i mean how many times have you watched one extra episode of game of thrones or something and then oh fuck yeah that's that's that's me at the bottom quartile yeah of wiggle room and then maybe you wake up later maybe you haven't got work in the morning you know i mean god i said this to you before we got started but i was running night night clubs for my entire 20s 15 years and uh

the you know i mean god i said this to you before we got started but i was running night night clubs for my entire 20s 15 years and uh the first time i ever had a stable sleep and wake pattern was covid as an adult the first time i ever had it i would go dunning yeah i mean it's crazy i also have to say to you it's uh it must be interesting for you i wonder whether you've ever considered how many years of life you've saved on the entire planet because I certainly know that before your first episode on Rogan, I didn't care about sleep. Yours was the first time when you spoke to Joe, I think it was 1109, the podcast number.
And that was the first time that I ever thought, oh, I really need to care about this. Like, you know, the number of doctors or surgeons that end

up back in the same hospital after they've gone home to do this thing, but that was me. So I would,

you know, wake up at say 10 or something like that, get up, I'd train, a bit of a walk,

do whatever I needed to do, work. And then I'd set off to go to Manchester from Newcastle at

7pm, get there at 9.30, set up the club, run from 10 until 2, to cash the till, which is the most cognitively demanding task before you're about to finish, get back in the car, 2.30, drive back to Newcastle, get in at 5 a.m. And we did that, I did that once a fortnight for four years.
There would also be one night in Newcastle where I'd be up until at very least 2.30 in the morning because I washing the till at one of our so that we would call it a domestic event one of the home games as opposed to an away game and uh you know i'd alternate that with my business partner and then there was you know just the vacillations of being a 20 year old club promoter in the north of england so you know that was all of that stuff was happening and uh yeah that happened until i was 32 and then you know covid comes along and that's the first time in my entire life that i go to bed and i wake up at the same time and uh how did you feel did you feel subjectively any and be truthful just yeah yeah yes i mean uh look for me the single biggest determinant in my mood is my sleep um if i'm underslept uh also if i've slept in

that's a lot of that's to do with the story that i tell myself um i think i wanted to start becoming a morning person and i thought oh you know genetic night maybe we can get onto it genetic night owls early birds i must be one night owl thing it's like kind maybe but also you've had to survive in this industry for the last 15 years.

So maybe your body's just compensating for what it is that you have to do but i found that um the quality of my mood the quality of my thoughts uh my emotional regulation uh these things took a you know a marked uh turn for the better um i found myself being able to regulate my appetite more uh what it was that i

wanted to eat even if i was getting the eight hours because i wasn't getting ripped around by basically doing shift work uh that didn't happen um yeah a lot of things my ability to introspect changed as well lots of things yeah and isn't it it's almost like being in a room where the refrigerator compressor turns off, and it's only when it turns off that you realize it's been on all the time. Correct.
I just thought that was like. Exactly.
And it's only when you finally disengage from the brutality of that schedule do you realize, my God, this is not me in my 30s. There's a different form of me sitting underneath all of this.
Well, I mean, this is the bizarre thing when you start to think about who are you and what does it mean that you have a nature? Well, okay. You have a nature.
You have a disposition for anger or discomfort or introspection or sadness or happiness or whatever it might be, joy. Okay.
let me double your testosterone. Just that, one intervention.
Now let's see what you think you is. Well, you are still you, but also the daily experience of you, the sort of landscape that you inhabit internally and the way that you show up externally has probably changed at least somewhat.
Okay, let me chop your sleep in half. What does that mean? Like, who are you on half the amount of sleep for two weeks? Who are you now? Well, you're still you, but we have this sort of sense of who we truly are, which is kind of like a best version of us, like a flourishing, thriving version of us.
And then we have this other one. But again, as you say, you know, kind of like the Stockholm syndrome of our own sleep deprivation or sleep irregularity maybe, we don't know who we could be or who we are with regards to that.
And over the last 18 months, I've been fighting with sleep again, sort of really trying to dial in sleep quality and struggling quite a lot. And that again makes me quite, okay, well, what is it that I'm fighting with here? How much of this is me and how much of this should I identify myself with? And how much of this is just a by-product of what's going on at the moment? It's really interesting.
And you've also got to ask yourself the question at some point, you know, what is it that I want out of life? Because I think so often in life, you know, the professional gun goes off and you're off into the rat race. And the thing is, even if you win the rat race at the end of the day you're still a rat so why not just stop and look up and firstly ask do i even want to be running in that direction and do i want to be this physiologically kind of distraught person by way of that run that this life is is enacting on me and that's what it was with and now being shortened as well and you're right precisely and also it's not just that we're going to live a shorter life but that shorter life is going to be more likely filled with disease and sickness which is not your lifespan but your health span and i think what you're describing, we do a large amount of work in sleep and mental health.
And I would say that one of the most sensitive faculties that is, that takes a nosedive like a dart into the ground when you are even sleep shortened versus totally sleep deprived is your mood and your emotional stability. And we understand all of the

brain mechanisms as to why, but when you're getting sleep, a la the COVID experience, my guess is that you woke up and you are now dressed in a different set of psychological clothes. And sleep is almost like a set of emotional windscreen wipers that it just adds the rose back into the tint of your life glasses every single day.
And when you look, it's not necessarily, and we've done these studies, when you are underslept, it's not as though you slide down into the negative more and you experience negative things more negatively. You do somewhat.
The main thing is that you lose the pleasurable feelings of normally pleasurable things that's what we call anhedonia the lack of the ability correct and anhedonia is the principal underlying feature of depression and that's why we see such strong links between you know sleep in fact in the past 20 years studying, we have not been able to discover a single psychiatric condition in which sleep is normal. To me, that is one of the most, I think, demonstrable indications of this tenuous link between your sleep health and your mental health.
They are so intertwined. And there's a lovely quote by an American entrepreneur, E.
Joseph Kosman. And he once said that the best bridge between despair and hope is a good night of sleep.
And that's exactly what the data demonstrate. What else is there to say in regularity? So we mentioned gold standard, 15 to 20 minutes of wobble for sleep time, 15 to 20 minutes of wobble for wake time.
Yep. Black standard at the bottom end, bottom quartile, two hours of wobble.
So from when you typically, on average, would go to sleep an hour earlier, an hour later, and the same at your wake time. Is there anything else to say when it comes to regularity? I think there is.
I think it's probably you, you came onto it beautifully with the Netflix, you know, description, which is where most of us get hammered with our regularity is the front end of sleep, going to bed. And the Netflix phenomenon is really what we call sleep procrastination, which is you are plenty tired enough to sleep, but there are things that are getting in the way, be it online shopping, checking social media.
And what to do about that? I would just at least say, set a to-bed alarm, not just a wake-up alarm, but a to-bed alarm. It goes off one hour before bed, maybe even let's just say 30 minutes before bed and live in the real world at that moment at least dim down half of the lights in your house and see if you can do at least a digital detox fine keep watching your netflix on your tv but for the most part see if you can put your phone away my goodness that's the other thing that will activate you we used to think it was the blue light from tablets and screens.
And there was a great study from Harvard that indicated certainly one hour of, you know, blue light exposure before bed blunts something called melatonin, which is bioactive nighttime hormone, which signals sleepiness. And it certainly did that and it disrupted sleep.
And we were all on the good bus of blue light is, you know, the nefarious agent that will, you know, fleece you of your sleep. Then came along some great work by a guy called Michael Gradazar.
And he actually argued now, I think very powerfully, it's not the blue light. It's that these devices are attention capture devices.
And they are designed to ruthlessly fleece you of your attention economy. My goodness, are they good at doing it because they've spent hundreds of millions of dollars developing that technology.
And as a consequence, you become so cerebrally activated that it masks your state of sleepiness. so you could be saying, okay, if there was an electromagnetic blast that came through Austin at 11 p.m.
at night, you would normally say, look, I'm not sleepy until midnight. And I just don't feel sleepy right now because I'm on my phone and you're getting activated.
All of a sudden that goes out within 10 or 15 minutes, you actually get hit by this wall of sleepiness and you think, Jesus, I actually am pretty sleepy because it hits the mute button on the signal, the physiological signal of sleepiness because it overdrives it with activation. Well, I mean, the converse, which is pretty easy.
I think that you're so right as well, that there is something triggering about activating about that kind of use you're involved it's engaging you're you're sort of thinking about stuff it's kind of passive but boring at the same time but also engaging very interesting but i used to use it if i was stuck in traffic or whatever and i was tired after driving back i would make sure i had a really compelling youtube video on so i would use that that effect on the opposite side. You would reverse engineer it.
Yes, it'd keep you awake. Exactly correct.
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I'm interested in, I saw a study a little while ago, I don't know whether it ever got replicated, looking at e-readers and looking at the effective e-readers. Most of them now, you know, the best Kindles have got a warmth level as well as a brightness level.
Have you looked at a lot of people want to read, but if you're reading and you're reading a paper book, that means you've got to have a light on, light's quite bright. So you can go to a Kindle and you can pull that down, but that's a screen.
Have you looked at anything to do with light exposure from e-readers impacting sleep quality? Really interesting. And that's actually a great way to continue to engage with digital media in terms of reading, if that's all you're doing.
So the page is black, the text is a cream or a white, therefore the amount of looks that's coming from the screen is already lower versus because obviously the background is the far more dominant constituent of that page so black paper white text that's perfectly fine you've got to be a bit careful in terms of what you're reading if it's the content you know if it's all sorts of salacious stuff then you know maybe the heart rate is going in the wrong direction but for the most part that's completely fine. But I would say two things about your phone.

If you have to take the phone into your room, because again, I don't want to be puritanical. That genie of the phone being in the room is out the bottle and it's not going back in, no matter what I say.
Two rules. If you can, you can find some software that can try to turn the screen monochromatic.
So everything goes black and white. and it's pretty surprising at how

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the you can find some software that can try to turn the screen monochromatic. So everything goes black and white.
And it's pretty surprising at how reduced in terms of the activation. My phone's next door.
Let me show you this. I'm going to hang on.
Wait there, people. I promised people who are listening, we did not plan this.
This is completely. So you'll know that there's a accessibility function that allows you to turn things grayscale.
Have you ever seen anyone do that? Oh, that's genius. And turn all of the blue off and turn it just red.
So you can see here. How on earth did you do that? Just internally on iPhone.
So you go into settings and accessibility, and then the same as you triple-click to go grayscale, the same function, but you just use the slider on the on iphone so you go into settings and accessibility and then you the same as you triple click to go grayscale yeah the same function but you just use the slider on the red side you kill all of the color except for red and that means it's so much darker so when you do this especially if you need to use it a little bit later on an evening uh you just and i triple click and it goes from you just stack the two things which is first it's almost monochromatic but second it's desaturated the blue light and it's the blue light which is the lower wavelengths that are most deleterious to harming your melatonin it's that black belt strategy blue light that's by the way do you know why it's the blue light that's so bad for your melatonin why it's so powerful in terms of is that because when the sun

is lowest in the sky in morning it's oh when the sun is highest in the sky sorry it's more blue and when it's lower and it's going through more atmosphere it's redder is that why some of that is true but it's not the main reason it's because where we evolved from evolved from the ocean from the sea. And there because of the way that light is refracted through water the principal color of the sea of the ocean are blues and so where we evolved our circadian rhythm originally was under the water and the way it was regulated was using light but the color of light under the water was principally blue because it was kind of desaturated from the reds and the yellows.
Isn't that amazing? That's so crazy. This isn't even reptile brain.
This is fish. Oh, no.
This is, you know, reptiles, amphibian, fish. We are way before, you know, avian and mammalian, you know, sort of emergence.
And by the way, it's only in birds and mammals that we see this thing called REM sleep or dream sleep. And it's a surprising thing.
And we still don't understand what that tells us about the functions of REM sleep. REM sleep is the principal stage in which we dream.
And before with every living species that we've studied to date sleeps, what that means is that sleep probably evolved with life itself on this planet and fought its way through heroically every step along the evolutionary path. Ergo, if sleep doesn't serve an absolutely vital function, it's the biggest mistake the evolutionary process has ever made.
And we now realize why it didn't make a blunder. But what's interesting is that what first came into being was this thing called non-rapid eye movement sleep.
And for millennia, there was no rapid eye movement sleep. There's no dream sleep.
Something happened when we went from amphibians, reptiles, and fish up to birds and mammals. Now, birds and mammals evolved separately in two separate lineages from reptiles, amphibians, and fish.
Birds have REM sleep, mammals have REM sleep. What that means, firstly, is that REM sleep evolved twice independently in the course of evolution.
When you see the same thing evolve twice or more times, like eyes, for example, it tells you that it's probably a fundamental trait of a living species. So what we don't still understand though is why do birds and mammals require, why did REM sleep emerge into being? Now we've got some theories because one of the differences is that birds and mammals regulate their temperature.
We are homeotherms. We get the ability to control our core body temperature.
All of those other species don't. So it has to be something to do perhaps with metabolic control to produce thermoregulation.
There's probably other theories too. but nevertheless going back to the evolutionary story and we'll come back to don't i haven't

forgotten the final T for QQRT, but I've put forward a theory that sleep actually never evolved. Why do we think that sleep evolved? Why don't we think that sleep was the default state of all life and it was from sleep that wakefulness evolved? I've always been confused why we don't.
Well, because you wouldn't be able to survive if you just slept, but you could survive if you just woke. The idea would be though that if sleep is this initial default state, it is enough to support life and its existence.
and some of those species could reproduce potentially asexually, so you wouldn't have to necessarily be awake to find a mate. You could at least have a proto version of life, and the proto version requires this stasis state that we call sleep.
It would somehow accumulate nutrients by falling through gravity. Correct.
you think of you know there's any manner of static living organisms that stay in place that don't move around but then at some point there was enough evolutionary pressure to demand this thing called movement and demand higher levels of consciousness and it was so that's one way of seeing it. I think the other is, let's say wakefulness came first.
Why don't we then just have wakefulness? Why do we need sleep? Sleep is clearly the price that we pay for wakefulness. That's another way around that we can see it.
So I've gone off on an evolutionary tangent there based on your brilliance, but I can always come back to the final T if you like. But- please.
Timing. Timing.
So timing. So QQRT, timing sounds like regularity and you think, hang on a second, that's one in the same.
It's not. Timing is your chronotype.
Are you a morning type, evening type, or somewhere in between? If you're an evening type, the headline piece of news is it's not your fault because it is largely genetically determined. There are at least 22 different genes that dictate your morningness or your eveningness.
And therefore you don't really get to decide. It's gifted to you at birth and it's very hard to change.
They tried it with a great study out of Australia where they took night owls who were kind of 1.30 a.m., 2.00 a.m. type people.
And they gave them, I think it was a total of 11 different rules, and I'll forget some of them, but it was wake up two hours earlier. As soon as you wake up, have breakfast.
Right after that, get at least 30 minutes of daylight don't nap cook caffeine off

after midnight don't nap in the afternoon in the afternoon if you go outside you've got to wear shades start to get dimness already eat two hours earlier and make sure that you're eating at least three hours before bed and then make sure you get into bed at least an hour and a half before you normally would do and they were able to bring those night owls back by about 60 minutes. But if you're going to bed at 1.30 a.m.
normally and you drag back, you're still a 12.30 a.m. type person.
And that was extreme. Imagine trying to do that every day for the rest of your life with those nine to 12 different rules.
The adherence to that protocol is probably going to be very difficult and sustainable throughout life. So even with all

of that extreme, it's hard to do. Why is your chronotype knowledge important? By the way,

you can just go onto Google and just type M E Q test, which stands for morningness, eveningness,

questionnaire test. It takes about three minutes and it gets you about 80 to 90% accurate close

Thank you. which stands for morningness, eveningness, questionnaire test.
It takes about three minutes and it gets you about 80 to 90% accurate close to your actual genetic chronotype distinction. So it's a pretty good test for what you are.
You probably already know what you are. You can probably answer it by a simple question.
If we put Chris on a desert island, nothing to wake up for, no responsibilities, no clocks, no nothing. What time do you think your body would naturally like to go to bed and naturally like to wake up? And the reason, by the way, I say your body rather than what time would you, you're already too biased by society's predilection to morning types are the best types.
You know, it's the early bird catches the worm type mentality. So you, I would, to which I would say, by the way, that the second mouse gets the cheese, but I'll, let's move on.
The, I would still say though, that it's so difficult to fight against that. And we see this also at the sleep center.
People will come in and say, I've got terrible sleep onset insomnia that I get into bed for the first hour and a half, two hours, I'm awake. I just can't fall asleep.
I've got insomnia. And then we do a chronotype test with them.
And for some of them, what we find is that they're a night owl and they'd like to go to bed at midnight. But because of the way life is structured for them, they're getting into bed at 10 p.m.
And they're awake for the first two hours. They don't insomnia they have a mismatch between when they're trying to sleep versus when their biology wants them to sleep and when you sleep in synchrony with your chronotype you get a beautiful distribution of quantity and quality when you fight against your biology you normally lose and the way you know you've lost is typically disease,

sickness, and bad sleep. So that's why I would always try to emphasize your chronotype as a critical last component.
So I think I'm probably a pretty good example of somebody that was like a,

how would you say, chronotype fluid. Oh, you're a genius, Chris.
I love it.

Being in my 20s. And like I say, I was adamant i'm just you know i'm a i'm a night owl um i finished my every single assignment at my two degrees at uni were all done at three in the morning you know that was sort of where i came alive i used to have my most my most sort of creative moments between about 10 p.m and maybe one in the morning i could really sort of drill down um and then covid comes along and i was i was already starting i mean this is after your episode on rogan had come out so i'd already realized i needed to start to prioritize sleep in a different kind of a way and then covid comes along i was like well i'll just see what happens i guess and i started to get myself a morning routine that was unnecessarily elaborate and then I over what, four, four and a half years since that came along, my natural wake time now is 7am.
If you don't put an alarm on, I will get up at 7am. I will go to bed.
At the moment, I'm going to bed at like 7pm or 8pm, which I need to have a chat with you about. But I will get up at 7am.
And I don't know, I don't know how much of it, you know, the chronotype thing, the night owl, early bird or something in between, although useful and powerful, I worry will be used by a lot of people to justify their poor or obsessive sleep habits in whichever direction that they kind of want to rationalize that they should take it. i say it's so natural i understand that absolutely i mean i was somebody that had stockholm syndrome from his own industry you know i like yeah the the whatever the prison guards had become my friends uh because i did what i needed to do in order to be able to survive in the world that i was living in but liberated from that free from that for a full year four years right I was no longer having to do this.
I was actually incentivized to maybe get up a little bit early because I could train and then prep and do the episodes and so on and so forth. Oh, well, it seems like my body works in a different way.
So yeah, very fluid in that regard. Yeah.
And I think, you know, you, so we definitely need to have a discussion if you're going to bed that early, because I'd love to see your sleep efficiency. Nevertheless, I think what that teaches us is much like sleep deprivation, you don't really know that you are sleep deprived when you're sleep deprived.
Your subjective sense of how well you're doing when you are not getting sufficient sleep is a miserable predictor of objectively how you're doing with insufficient sleep. And the analogy you could use as a drunk driver at a bar, they've had three or four pints, they've had a couple of shots, they pick up the car keys and they say, I'm fine to drive home.
And you say, I know that you think you're fine to drive, trust me, you're not. Let me just grab your cab, I'll take your car keys.
And it's also same with your your natural chronotype tendencies versus overdriving it and trying to force yourself to be let's say a night owl when you're actually not a night owl i would also say that when you start to get very regular and you sleep in harmony with your chronotype you start to not not need an alarm. And that's the other strange thing, by the way.
Human beings seem to be the only species that will deliberately deprive themselves of sleep for no apparent good reason. And often when people say, how do I know if I'm getting enough sleep? One question I'll ask is, if your alarm goes off in the morning, you wake up.
But if your alarm didn't go

off tomorrow morning, would you sleep past your alarm? If the answer is yes, then it tells me that your body's not done with sleep. And no other species does that.
They just sleep until they're done with sleep. But we will naturally terminate that for all sorts of different reasons.
And so I like the idea that you will wake up no matter what at 7am. It tells me something about your unique biology.
Now, my guess is that even if I put you into bed at 2am, you're probably not going to sleep the same duration that you would do otherwise. 7am won't be able to.
Right, exactly. Because your body has a natural circadian and rhythm that even when you're sleep deprived it will go on it's awesome upswing of a piston activation and wrench you out at 7am so you're getting closer to understanding what your biological rhythms are at least at sleep offset talk to me about the relationship between timing and regularity because it seems seems like those two are intrinsically linked.
Some people might have even confused it. How important is it to get regularity if we're getting enough of it? Like sleeping during the day, but staying up at night, you already mentioned, kind of dampened it a little bit for the night owls to say, you know, it's not your fault and so on and so forth.
But I imagine that there is some predictive power for mortality for people that are waking and sleeping more aligned with when the sun is up, when the sun goes to bed, et cetera. More aligned if they're sleeping in harmony with their chronotype.
Okay. So if evening types are sleeping like morning larks, their sleep quantity is shorter, their sleep quality is far worse.
And that's the reason why they have higher rates of mental illness, psychiatric conditions, higher rates of diabetes, higher rates of obesity, higher rates of hypertension, stroke, and heart attack. So you can see that the consequences of fighting back against that biology now it can also work the opposite way too if you've got a morning type that's sleeping like a night owl which rarely happens in society because society is so biased come a club promoter towards exactly but you are the archetypal example what happens there is that you are going to bed late and you will necessarily, you will still be short slept.
Now the night owl that's getting forced to sleep like a morning type is going to struggle to sleep on the front end because they're not ready for sleep. Your problem is the opposite.
You are going to bed far later than you would normally naturally like to do, and you will fall asleep ever so quickly. The problem is you want to get your seven to nine hours and sleep later into that morning, but you're awake at seven.
That was less of a problem when I was younger. Again, this whole thing sort of started when I started to get regularity.
It was like, I don't know, I was an MMA fighter from a sleep perspective and sometimes ground and pound and sometimes stand-up game and other times it was Brazilian jiu-jitsu, whereas now I've just pivoted into one particular type. So I think giving myself a little bit more structure has resulted in a kind of lock-in with my sleep that I didn't have before.
I was able to shift that window around. And again, maybe it was not too dissimilar to squeezing down sleep so that you get sleep efficiency.
Everybody that's a shift worker that's listening to this are most of the people that shift workers because I would imagine if you couldn't deal with it, if you weren't, if you were insufficiently sleep flexible, when it comes to moving around your shift work, you would have lasted a couple of years and been like, I can't keep doing this. It's just going's gonna kill me right um so yeah again we're very adaptable at least for me uh we're very adaptable i had a full uh intellix dna uh genetic screen done which was the super uber platinum everything everything everything nothing came up for uh sleep a bunch of stuff for sort of dopamine epi nor epi uh but nothing really came up for sleep so that was kind of interesting to me so i guess a question i've got what happens to all of the cues the r and the t as we age over time what what starts to get manipulated and changed in terms of all of those as we grow up as we we get older? Yeah, bloody great question.
The first two cues get much harder. It's much harder to get the same amount of sleep that you did in your 30s, 20s, or 40s when you're 60, 70, or 80.
And this is one of the myths in sleep. People used to think, well, older adults need less sleep.

And if you look, they'll on average get maybe six, six and a half hours of sleep.

What we now understand is that older adults still need the same amount of sleep as they

did when they were in their forties.

The difference is their brain simply can't generate the sleep that they need.

And I've always been perplexed by that mentality of people just saying, well, ultra-double-double-double-double-double-double-double-double-double-double don't need bones that are as strong in later life. No, we don't say that.
We treat them with calcium and resistance training to try to maintain that bone density. Why don't we take the same mentality with sleep? So firstly, quantity gets much harder.
It's harder to generate the sleep. And we know why, because as we get older, just like our body deteriorates, our brain also deteriorates.
The problem is that your brain does not deteriorate in a homogeneous manner. What I mean by that is some parts of your brain rapidly deteriorate, or at least more rapidly than other parts of the brain.
And when we've mapped that, what we call brain atrophy, and you can almost play a movie now where you look at it across decades and you can see these beautiful morphological changes in the brain, the two areas that,

or at least one of the main areas that generates your deep non-REM sleep is right here in the frontal lobe, right in the middle, called the medial prefrontal cortex. That area is the epicenter for the generation of deep sleep.
And that degrades most rapidly when we get older. So unfortunately, the aging brain is a sleep dependent aging brain.
It's especially sort of ravaged by the process of chronology relative to other parts of the brain. So that's the first issue.
The second is quality. And quality is here coming back to you are nice and continuously asleep for most of the night versus you're awake, you're asleep, you're awake, you're asleep, or you're awake for long periods of time.
That is much more like age-related sleep. If I were to show you sort of the, what we call a hypnogram of sleep, which is what you see on your sleep trackers, it looks time of night along the horizontal axis.
You've got this different sleep stages and you go on this beautiful rollercoaster ride, REM, non-REM. But then if you look at the aging brain, you've just got all of these kind of like a dolphin going up, surfacing for wakefulness all the time.
It's fragmented sleep, poor quality of sleep. Part of the reason is because the release of melatonin is not in this standard beautiful where melatonin peaks just before you go to sleep, stays high and then drops down low.
You just get this really flat profile of melatonin as you get older. Secondly, you've got the sleep generating, the deep sleep generating brain regions deteriorating.
So you can't stay in deep sleep. You surface in these lighter stages where you're more vulnerable to being woken up.
And then the other sort of component of age-related sleep decline comes onto the aspect of your chronotype. You are given your chronotype at birth, but it's highly age dependent in terms of where you're sleeping on the clock face.
So as let's say a six year old, we all wanted to be awake with the adults at the weekend and try to stay awake. And we would try and try, but you know, I just remember at nine o'clock being kind of like lifted up to bed because I'd fallen asleep.
It used to annoy the living daylights out of me. So there, even though I'm mostly a neutral, I'm kind of like an 11 to 730 kind of guy there.
I still had my neutral chronotype, but as a child, my neutral chronotype was sort of nine to 6 AM in the morning. And then as I got older, I moved forward in time and I found my adult sweet spot.
But then per your question, as you get older in late life, now you start to regress back and you become more childlike. You want to go to bed earlier and wake up earlier.
It's the reason that if you go to Florida, you know, when you've got a lot of retirees, you've got the early bird special where people now are eating at 4.30. You know, they finish their meal, they're home by eight and they're in bed by nine because they've regressed.
But even if you take, you know, 180 year olds in Florida, you'll still get a distribution of some people wanting to go to bed at, you know, 8.30 p.m. Others more close to 10 p.m.
There's still the variability of morning types and evening types. It's just that where that morningness and eveningness sits on the 24-hour clock face gets dragged around across the lifespan.
I know that's a complicated way, but does that make some sense? Absolutely. Okay.
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One question I had, do sleeping positions matter? Why? Why do people have habits when it comes to their sleeping positions? It's really interesting that people say, I'm a back sleeper, I'm a side sleeper. That's not really true.
You will typically sleep in almost all of those positions throughout the night. It's just what is the dominant position.
And when people say I am a X sleeper or Y sleeper, you're just talking about what you typically do more often relative to the other positions. More people are side sleepers than front sleepers or back sleepers.
About 60% of people are most often side sleeping. Position doesn't matter with probably two exceptions, although one of them has an asterisk, which is I don't want to skirmonger.
The first is definitive. If you are snoring, if you have sleep apnea or undi- if you know anyone who's snoring and they have not been tested for sleep apnea, go and get them tested.
Or if you are, go and get tested. It's real easy to figure out if you're a snorer or not.
Download an app. I have no association with them.
It's called Snore Lab, Snore L-A-B, Android, Apple. You open it up, you hit record, you place the phone down by your bedside it listens to your snoring and then at the end of the night you can see the amount of snoring and it grades it from quiet moderate loud and epic and you see these richter shocks throughout the night the worst still you can then go and tap at any moment in your

night and you can listen to yourself gasping for breath and snoring because snoring, what happens when you snore is that the airway starts to partially collapse. And when it starts to partially collapse, like a straw that gets bent, sort of, you start to get these fluctuations, these eddies in the airway.
And that's the sound of, that's the partial collapsing of the airway. When the airway collapses completely, the straw goes flat effectively.
That's when you stop breathing entirely. And you can be there for 15, 20 seconds and your blood oxygen saturation just starts to plummet.
And at some point, your brainstem, which picks up the ratio of the gases in your bloodstream between carbon dioxide and oxygen says break glass in case of emergency. We've got to wake him up.
And that's the moment where you hear and you gasp and you're back up again. As a consequence, you're never going into deep sleep.
You stay in those shallows of sleep. Now, mild sleep apnea, if you have these, what we call apnea events, and apnea is a word, it's beautiful.
Panea is breath from a Latin derivative. Anything in medicine that has the word A before it is usually the absence of it.
You know, arrhythmia, the absence of a normal rhythmic heart. Apnea is the absence of breath.
And mild sleep apnea is you having maybe five to 15 of the events per hour. That's how we grade it for each hour of sleep.
How many of these events are you having? Mild sleep apnea, let's just call it 10 events. And you're asleep for eight hours.
Imagine if I were to come in and say, tonight, Chris, I'm going to come into your room and for the entire night, maybe 80 times throughout the night, I'm going to come in and I'm going to throttle you around your throat to the point where your oxygen saturation drops below 80%. Do you think you're going to feel good by tomorrow morning? The answer is no.
But so many people are living with undiagnosed sleep apnea.

We think at least 80% of people who have sleep apnea are undiagnosed right now.

And that will put you in an early grave.

Is snoring the same as sleep apnea?

No, it's not.

You can have snoring and it will not classify as sleep apnea.

You still want to understand why you're snoring.

But nevertheless, you can just get a very simple home test. In fact, you can look at your risk for sleep apnea already.
Go online and type in the search term stop-bang questionnaire. Stop-bang questionnaire.
And again, it takes probably two minutes to fill out and it will give you a risk hazard ratio of how likely is it that you have sleep apnea. And it correlates very well with an at-home sleep apnea test.
So it's a good quick proxy. I love SnorLab though.
That's another great way to frighten yourself into understanding what's exactly happening. So all of which to say, I think I'm forgetting how we got here, but nevertheless, sleeping position is one of those situations where when you are lying on your back, you are allowing your airway the direct access to this thing called gravity.
And when gravity is present with back sleeping, it's far easier to pull that straw flat shut. So that's why we typically don't like people with sleep

apnea sleeping on their back. The old school approach, gosh, when I was coming up to sort of

start to treat was, or to at least get you away from a back sleeping position, was you would ask

the gentlemen, usually they're more heavy set, you would ask them, find a t-shirt from your wife,

usually smaller, and get that t-shirt that has a pocket on the breast. And then I want you to

Thank you. ask them, find a t-shirt from your wife, usually smaller, and get that t-shirt that has a pocket on the breast.
And then I want you to wear that tight t-shirt back to front. And then I want your wife to take a tennis ball before you sleep and put it in the pocket.
And every time you roll over, it's so uncomfortable that you train yourself out of back sleeping. And so that's the way, that's the old school.
So why do we have preferences for sleeping position? Is this chronotype? Is this just habitual? Can we train ourselves out to be- Usually based on your skeletal ergonomics and how you want to sleep. It's also in part driven absent of your body based on your mattress.
And so that's why, you know, having a mattress that's at least supportive enough where you don't get that banana bowing, because if you are a front sleeper and you're sleeping on a poor mattress, then all of a sudden you just get this every night, this bending of the spinal cord and you're lying there. I mean, just say, okay, today for eight hours, I'm going to have you compressed into this banana shape lying on your front.
And then at the end of that eight hours, get up and, you know, do 10 jumping jacks and feel great. Not so much.
So you've got to be mindful of the position. So I would say sleeping on your back, if you're a snorer, not so great.
There is some evidence that sleeping, and I'm going to forget which side it is now, I'm trying to think of my anatomy, but sleeping, I think it's's on your left side based on how your gastrointestinal system is working leads to a greater degree of GERD which is gastric reflux in other words getting heartburn just get reflux interesting so that's the the second one though really that i was going to mention mention is sleeping on your front or on your back may not necessarily be ideal because what they found is that during sleep and this quick tangent, I'll come back to it. But another one of the new functions of sleep is brain cleansing.
That when we go into sleep, your brain essentially has this sewage system that kicks into high gear and it washes away all of the metabolic detritus that's been building up across wakefulness because from a biochemical perspective wakefulness is low-level brain damage sleep is your sanitary salvation and two of the pieces of metabolic detritus that that sleep system will cleanse your brain of are beta amyloid and tau protein, which are the two culprits that underlie, we believe, the Alzheimer's disease cascade. And what's interesting is that when you are sleeping on your side, these are animal studies, they found that that cleansing system is more efficient than when you're sleeping on your back or your front.

And what they did was they showed this in rats and in mice. And then I was watching this, I was at the conference, they started to show you pictures in the wild of every single animal sleeping.
What was common across all of them, no matter how they contorted their body, the common ingredient was that their head was always on one side or the other. As if that was the natural sort of tendency, the predilection of how sleep was optimally designed.
And they argued that the reason for that is because that's when you get greatest optimality of flow of this, what we call the glymphatic cleansing system. Now, I would say that I haven't seen strong replication of that, nor have I seen any evidence that that's true in human beings.
Human beings are very odd species. Our head is tilted 90 degrees relative to many others.
Think about a giraffe, a donkey, think about a dog, a cat. Their head is lifted up in line with their spinal cord.
When we went from being quadrupeds to bipeds, one of the things that had to happen because we were walking on all fours with our head out like a dog, if you then stood up on your back legs but kept the head in that same position, all you're doing is looking, getting a very deep interest in clouds. So our head tilted down 90 degrees.
And so that means that our ergonomics of the head and the cranium may be very different to animals. So I think the jury is out and I don't think that's any good reason for you to start worrying about, oh my goodness, I've got to get my head to the side.
And if I'm not, if it's down on the pillow or I'm on my back, don't worry about that. Is there anything else to say on snoring, people that snore, why we snore, and then sort of progressing through that to treat sleep apnea? I would simply say that coming back to being insufficiently slept and that mood dysregulation and you not knowing what you, the true self, actually was, is ever more true in untreated sleep apnea patients.
And I remember we were doing a study with one group and we started to treat these individuals. Now, there are numerous new treatments out there.
If you have mild sleep apnea, you may not need one of these masks, these nasal pillows, which are called CPAP machines, CPAP, and it stands for continuous positive airway pressure. This little nasal pillow pushes pressured up your nose and it acts like an airway splint to keep the airway open so it doesn't collapse.
Now, if you have severe sleep apnea, I know that these machines can be invasive, although people like ResMed have really great machines. Now the old school kind of mask fighter pilot, Tom Crude, those were tough to live with.
Now they're much better. Nevertheless, I would say, even if you feel as though you're not, you're struggling to sleep because of this kind of pipe that's coming off you, that's still far better than you sleeping without it and having the horrific oxygen desaturation and minimal sleep quality that you get otherwise.
So nevertheless, if you have mild sleep apnea, you now have these mandibular augmenting devices. So it looks like a sports gum guard top and bottom, but it's hinged.
And what it tries to do is move the lower jaw forward by just a couple of millimeters. And what's fun is that you can do this test at home, lie on your back and just sort of lie there and start making the snoring noise.
So I can make the snoring noise and then just try to move your jaw forward. It's actually much harder to snore and it's a tiny change anatomically in the jaw,

but it can make a vast difference. So now these new mandibular devices are out there.
There's all sorts of new ways. There are also, some people obviously rightly don't wish for this.

There are more invasive surgeries where you'll put a neurostimulator that stimulates the airway

and forces it open and that saves you from having the CPAP machine and some people end up. Permanent CPAP machine.
Yeah, it's a permanent CPAP machine. So there are lots of great ways to treat it.
What about snoring? What about reducing snoring, something that's presumably more common than sleep apnea? Yeah. So there I would probably go to a mandibular device, speak to your dentist.
If they don't know about it, go find a dentist who does. They can make up these devices and most of them are covered by insurance.
You can buy them on Amazon. Make sure that you just look at the star ratings and make sure it's rated by at least a couple of 500, 600 people and then believe the rating.
And you've got to get a bit used to it. And, you know, I've, I actually about three or four years ago, um, because I would track

ruthlessly every night, my snore lab, I could start to see a little bit of snoring coming on. Now that's just my age as we age, you know, just like the rest of your body, it becomes a bit saggy.
My muscle tone isn't what it used to be. And so I started to see signs of very mild sleep apnea.
I wasn't in anywhere close to the region of needing to be treated, but because I know so much about sleep, I don't want to live a shorter life, nor do I want to live a life with disease. So I just bought myself one of these devices.
I ended up then having a great dentist friend who specializes and we actually got the proper device, sort of custom device. But you can buy them on amazon you put them in hot water you buy down gum guard and they're actually not too bad as if you can tolerate them for smaller people who don't have jaws like my jaw and certainly your jaw you know it's going to be a bit you know tougher you know my wife very slim refined woman you know she's probably not going to be able to tolerate it because the jaw mass is just not sufficient so you've got to be i'm not trying to say it's a one size fits all for everyone but for those who can if you have some mild snoring it will clean it right up it's very impressive in other news shopify powers 10 of all e-commerce companies in the united states they're the driving force behind gymsmshark and Skims and Aloe and Nutonic.
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Right now, you can sign up for a $1 per month trial period by going to the link in the description below or heading to shopify.com slash modern wisdom, all lowercase. That's shopify.com slash modern wisdom to upgrade your selling today.'s talk about sleep and relationships i think uh two people trying to sleep together wonderful pairing they're so in love everything's great and yet the one of the best predictors for their lifespan their health span their mood their emotional regulation the way they feel the next day their achievement of their goals their memory the fact that they're not going to fall asleep at the wheel and die.
Wonderful. That's my next book right there.
Chris Williamson. Wonderful partners in waking, terrible partners in sleeping.
Talk to me about the relationship between sleep and relationships. Yeah, there's some really great research on this.
Pioneer in this field is Wendy Troxell wrote a great book. And what we find is that if you survey people

and you ask, do you sleep in the same bed together? One out of four people will say that they do not sleep in the same bed. And if you then survey them anonymously, because there's such a stigma are associated with not sleeping together, about one in three couples will say, I wake up in a different location than this bed that I went to sleep in with my partner.
So in other words, they got up during the night and they just went and they got on the couch. Yeah, exactly.
So it's certainly a common practice and it's increasingly so. This idea, I think poorly named, which is this idea of a sleep divorce to prevent a real one.
And I'm not suggesting again here that it is a one size fits all. It's absolutely not.
Some couples can sleep together and they sleep really well and they have a preference for that. What's interesting though that if you measure them objectively you always see that when couples sleep together versus when couples sleep separately their sleep is always objectively as we measure it with sleep trackers or you know polysomnography in the laboratory it's always worse when they're sleeping together on average than when they're sleeping separately however if you ask them subjectively what do you think of your sleep they'll say well about half of them will say i actually feel my sleep is much better quality when i'm sleeping with my partner versus when i'm not some of that has to do with perhaps the societal bias that they think they have to cleave to others it, it's about safety, that they just feel safer.
Others, it's just more intimate. But what we have definitely found is that if you start to undersleep a male, if you short sleep them, and if you look at the average data, they could be in bed, let's say seven hours.
With a partner, they could down to around five and a half hours because of the sleep disruption. If you put a male, healthy male in their twenties on five hours of sleep for five nights, they have a level of testosterone of someone who's 10 years older than them.
So, and you see equivalent impairments in female reproductive health, follicular stimulating hormone, luteinizing hormone, progesterone. These are all critical sex hormones that promote superior libido drive, and it also promotes superior sensation and sexual pleasure during the act of intimacy.
So firstly, when you're underslept, and again, this is not a one size fits all, but for those that it's not working for, the stigma in society is that if you're not sleeping together, you're not sleeping together. But in fact, the opposite seems true because you replete your sex hormones.
We also know that for every one hour of sleep that a woman gets, an extra hour of sleep that a woman gets, her desire to be intimate with her partner increases by 14%. Now, if you think about the latest libido drugs for women, things like Vileci, those will improve libido by about 23 to 24%.
That's a pharmacological brute forcing agent. But here- 90 minutes of sleep.
One hour of sleep and you're getting there. So all of a sudden, all the guys now are probably calling their girlfriends or their wives, honey, we need to go to bed an hour.
Yeah. Should we get into bed an hour and let's sleep in? Come on.
Let's have a... So there's certainly a superior benefit when you are sleeping well as a couple, your physical component of intimacy is improved.
We also know that when couples are sleeping well, from a female perspective, at least, you get, by way of those sex hormones, you get greater vaginal lubrication, which leads to higher pleasure during sex, and you get greater sensitivity of the genitalia for both man and woman in terms of the intimacy. The other component, though, is the psychological component.
When couples are not sleeping well, for example, when they are sleeping together, firstly, their empathetic sensitivity is blunted. Secondly, as a consequence, they end up butting heads more in the relationship.
And furthermore, because their prefrontal cortex, which is the kind of higher order reasoning, logical area of the brain, that's the one that goes first in terms of sleep deprivation. It's the same one that is there designed to do conflict resolution.
So you are enfeebled as an organism to have a co-opted relationship that's emotionally mature and designed to be part of a team versus adversarial and combative. And so shorter nights, greater fights.
That's what data starts to demonstrate.

Then you can ask, well, okay, if I decide to sleep in separate rooms, how can I firstly approach that with my partner and how can I design it? the first thing i would say is approach your partner with curiosity and a non-binding agreement. Go to your partner and say, look, have you ever thought about us maybe trying to sleep in separate locations so we sleep better, so we're better together as a consequence? Would you be open to just saying, look, for the next two weeks, we try sleeping apart.
And if we agree that it doesn't work, we just go back to sleeping together. Would you be open to that idea? So you make it non-threatening, you approach from a level of curiosity and you don't make it binding that from this point forward, this is what we're doing.
Then how do you design it? What we most of us miss by sleeping together is the bookends of sleep. Because in between, we're largely non-conscious.
So you can say, look, if before we go to sleep, I'm just going to come into your room and we're just going to have a kiss and a cuddle and we're going to do what we're going to do, the front end of sleep. And then whoever wakes up first, you can go through to the kitchen, make the coffee.
And the person who is waking up second, just text your partner. And now this is, you know, utopian world where no one's rushing out the door to go to work.
But if you have the chance, then just text your partner and say, hey, I'm awake. Come in, give me a cud a cuddle give me a kiss and that way you get what

you wish for which is the buck ends of sleep of intimacy cuddling and all of those good things but you still get to sleep apart what is it that's happening when people sleep together that's causing the disruption for the most part it's usually two things it's the it's the territorial non-conscious fight for the top surface called the cover.

Right.

Okay.

Yeah.

The kind of tug of war.

And the second is the distribution of disturbance along the base of the bed, which is I'm tossing and turning. And you, therefore, may not even remember that I woke you up.
But my movement still- Like a train going past outside and it- Correct. Yeah.
And you roll over, you're back into shallow sleep. And then the other person has rolled over.
And now that was just at the time and they're adjusting themselves just at the time that you fell back asleep after you were the one who caused it. And now you're awake again.
So firstly, there's the non-conscious physicality of top and bottom sort of surfaces being moved around. And then the other is snoring.
It's the other, you know, if you ask a lot of usually women, because now women get sleep apnea and men get sleep apnea. It's just that it's probably at a rate of about three to one ratio, men getting sleep apnea.
It's about the opposite for insomnia. Far more women have insomnia than men.
It's not to say that men don't have insomnia. High neuroticneuroticism? It's usually because anxiety disorders are about twice as common in women than in men.
And anxiety, just as we spoke about, is one of the principal underlying mechanisms through which we understand this thing called insomnia. Okay.
Did you see on Reddit quite a while ago that famous couple sleep study they did where they ended up with the Tuve solution? Yeah. What do you make of that? Because because i've had a number of friends i have one friend who i'm not going to name i have two friends one friend who a year ago actually it was done on the show is george so george um fully committed to this having read that study on reddit and he had the classic partner's great but fuck we really the sleep is is lower quality than it should be and he was very much prioritizing it a la dr walker um and he pivoted to a two-way solution and yeah do you want to explain the two-way solution just for folks who two duvets two two duvet covers on the top of the bed uh this couple who had maybe using an aura ring or something similar had tracked their sleep.
The single best determinant of the wife's good night's sleep was the husband being in the bed. The single best determinant of a bad night's sleep for the husband was the wife being in the bed.
For clarity, I think it was the same. It was more of a decrease in sleep quality for the man as being on the period was for the woman.
So that was the sort of rate extent of yeah yeah exactly the the rate of impact and they tried everything lots of different solutions they didn't want to go to a two-bed solution so they went to a two duvet solution which presumably is as you said fixing the top surface yeah it's no longer a tug of war because it's two separate uh surfaces to play on so i guess is there not first off there must be companies, I at all of the eight sleeps and the you know the the helix mattress and stuff like that uh an extra extra wide bed that's got maybe some sort of segmented yeah um you know the honeycomb thing they put kind of portions off in the middle with a two-way solution i mean like how big does a bed have to be before it's one bed that is essentially two? Do you know what I mean? Yeah. Have you looked at solutions? Can you imagine the real estate territory we're talking about here at some point? Yeah, you're getting wider.
It's just an entire bedroom that's one mattress. Yeah, exactly.
It's a soft play area for parents. Keep your bedroom chit-chat to yourself, Chris.
What do you think about the two-way solution? you looked at that has it ever been replicated and then what about um solutions maybe people don't have sufficient bedrooms in the house to be able to move to two what can people do to make sleeping together better uh yeah yeah i actually think the two-way solution is a great one in fact if you look there's um equinox hotels uh the chain principally in new y. If you go in, they're highly optimizing sleep.
And I'm just starting to have conversations with them to see if I can help them with that. They already do this, where the King Bed will have, it's dressed in essentially two separate suites of, you know, your sheets and my sheets.
They've got an eight sleep on them all as well, right? They've got a cooled mattress. I don't know if they have eight sleep yet.
Okay. But certainly they, yeah, they probably, I'm sure they do, but they've already figured this out and it's kind of a genius move, but there's a more extreme version of that.
And it's called the Swedish method. And it sounds highly salacious.
It just turns out that this was a method pioneered in Sweden, which is simply that you get two twin beds, you them together side by side so you're still sleeping essentially next to each other but there is complete separation between church and state as it were and therefore the bottom and the top is segregated rather than the tuve where the bottom is common duvet is split and this way with the swedish method you do top and bottom which sounds

very it's a little bit it does sound very swedish um anything else i'm so glad you're not cutting that part anything else to say on uh sleep and relationships um i would say that certainly sleep affects sex, meaning that when you are getting sufficient sleep, it can promote a greater degree of physical intimacy and pleasure. Sex also impacts sleep though.
And what we found, we in the royal way of the sleep field, is that sex that is associated with orgasm ends up

producing about a 70% improvement in subjectively reported sleep quality.

Regardless of time of day?

Regardless of time of day, it's higher in men than in women. So women, it's about a 64%

improvement. In men, it's about a 72% improvement men it's about a 72 improvement but it's still you know demonstrable now for some people listening maybe you don't have a partner so but all is not lost because it turns out that masturbation associated with orgasm results in about a 50 improvement why in part of it is probably because of certain other social bonding hormones like pro, well, probably if you look at some of the data, there is probably vasopressin for men.
And then if you look at that sort of the classic hormone of bonding, which you, have you spoken about? Oxytocin.

Oxytocin before. Yeah.
So oxytocin, that's more so in females than in males.

That's depressing for men is so fascinating.

And it's, oh, don't get me, yeah. And I've started to speak to Peter Tia, you know,

because he used to use it for all sorts of sleep related reasons. But those hormones

typically are released by way of pro-social activity. Now, when you're by yourself, you don't get that added benefit.
So there is something about, and I think what's happening with orgasm is that you're very sympathetic. You're very fight or flight.
You're getting very activated. Your heart is racing, but then afterwards it's that kind of cigarette cigarette moment in the movies where all of a sudden you're just spent and you go all the way over into the parasympathetic quiescent state and you're kind of done.
And that's the state that you need to be in. So firstly, I think from a hormonal and a nervous system perspective, that's why sex by way of orgasm is beneficial.
the benefit of couples or you know at least more than one person producing that added benefit from 50 to 70 is probably because of the pro-social hormones but nevertheless you can still get you know 50 of the way there so in terms of adding sleep credit you know you're making money hand over it's a good making money hand over fist but maybe I wouldn't say that let's not talk about fist so you mentioned there about nicotine about the cigarette after sex uh caffeine you know one of the most common uh stimulants that i think 80 90 percent of people use on a daily basis yeah it's the second most traded commodity on the surface of the planet after oil so it tells you everything it's the largest it's the largest drug experiment that's repeated on the planet every single day. Wow.
What is there to know about sleep and caffeine? Probably, I think most people now through idiots like me understand some of its temporal dynamics. What I mean by that is it's half-life.
Caffeine has a half-life of about five to six hours, which means after about five to six hours, 50% of that is still in your brain, which means it has a quarter life of 10 to 12 hours for the average person. So drink a cup of coffee at midday, perhaps a quarter of that caffeine is still in your brain at midnight.
It's highly dependent, however, on your sensitivity, which is determined by a specific enzyme. That enzyme is what we call a cytochrome P450.
It's a liver enzyme. And it's a variant on a gene that's called the CYP1A2 gene, which is just, you know, word spaghetti at this point, word salad.
But simply variations in that gene means that you are either quick at clearing the caffeine or slow. And everyone knows what type that they are.
And I'm pretty slow too. I am a caffeine sensitive individual.
But nevertheless, just keep that in mind that in terms of caffeine having that temporal dynamic, I would say the dose and the timing make the poison. Try to cut yourself off after about probably four cups of coffee maximum.
Three is probably really where I would draw the line. But again, it depends on your sensitivity.
That's not where it stops though, because even if you're one of those individuals that says, look, I can have two espressos after dinner and I fall asleep fine and I stay asleep. That may be true, but the caffeine will actually keep you out of the deeper stages of sleep.
And what we've, we did some studies where we gave you 200 milligrams of caffeine, which is a hefty, you know, drip, big whack sort of, yeah, cup of coffee after, after dinner. And that robbed you of about 15 to 22% of your deep sleep.
And to do that, I would have to add about 12 years of your life to your life so i could age you by a decade in terms of your deep sleep. And to do that, I would have to add about 12 years to your life.
So I could age you by a decade in terms of your deep sleep quality by just having, you know, two espressos after dinner. The other thing about caffeine is that it will fragment your sleep.
So it will litter your sleep with these awakenings. And just like alcohol, which does the same, but by way of a different mechanism, caffeine is going to reduce the quality of your sleep non-consciously because those awakenings are so brief, you never commit them to memory.
So you wake up the next day, you feel lousy, but you don't remember waking up, so you don't put two and two together. That said though, I've actually changed my tune on coffee.
I would absolutely say for anyone for whom they like coffee, absolutely drink coffee. And the reason is because if you look at coffee, the health benefits associated with coffee are astronomically numerous and remarkably robust statistically.
Furthermore, perplexingly for someone like me, if you list all of the benefits that it's de-risking in terms of diseases and you stack up what sleep will do in terms of de-risking all of your disease states, it's almost a one-to-one match. So people are coming along to me and saying, well, can you square that circle for me? I don't understand how that can be true.
The answer is that the coffee bean contains a whopping dose of antioxidants. And because we're so deficient in our antioxidant consumption, because we're deficient in our whole food dietary intake in this modern world, the coffee bean has been asked to carry the Herculean weight of all of our antioxidant needs.
So no wonder it looks like drinking coffee is associated with health benefits. It's not the caffeine.
It's the antioxidants. Case in point, if you look at the benefits that decaffeinated coffee produces, it's the same.
So it's not the caffeine, it's the coffee bean. I looked at the Whoop-Gurin review last year.
It's actually just come out recently and I haven't been through it. And they talk about your behaviors and what's been related between your behaviors and your sleep and your recovery and your strain and so on and so forth.
But they also have aggregated, anonymized and aggregated the data from all of the other Whoop users. The number one predictive behavior for a good night's sleep was caffeine.
The number one predictive behavior for a good night's sleep was caffeine. So is there a method, would you ever encourage somebody to use caffeine in terms of its timing to help bring you into land from an adenosine perspective so that you sleep more easily, so that your latency is reduced or whatever? From all of the data, there's nothing to say that you should advocate for it as a sleep aid.
I think there's some data to say it may be equivocal that at least moderate doses of caffeine have any effect on your sleep. The problem with some of that data is that it's associational.
So it could be that people who are drinking coffee are people who also are very thoughtful because they can afford- Healthy user bias. So yeah, healthy user bias.
They're the same people who are probably drinking two cups, then they're going to the gym, they're exercising, sleep is fantastic. That's right, exercise is fantastic for sleep.
But that's the interesting thing about the WHOOP data though,

because that is a relatively, I would guess,

homogenous group of people,

all of whom have got a wearable.

They're tracking lots of things.

And even within,

because these are behaviors done by different,

or the same individual on different days.

It's within subject design is what we call it.

Sort of longitudinal within subject.

And so the other possibility is that, that it's still on days when you're drinking caffeine are days when you are more fatigued more fatigued see this is why we need a scientist to help me pick this apart okay so that's sleeping caffeine what about sleeping alcohol yeah drink lots of it fantastic for your. Said like a true brain.
It's right there on our passports. Alcohol is probably the most misunderstood sleep aid that there is out there.
Alcohol is in a class of drugs that we call the sedatives. And sedation is not sleep.
But when you have a couple of nightcaps in the evening, you mistake the former for the latter. And if I were to show you the electrical signature of your sleep with alcohol versus without, you would see how different it is.
It's not the same. That that alcohol will actually, it pushes you into what looks like deep, slow wave sleep.
But it's kind of the more, the faster slow brainwave activity. So it's sort of the more less nutritious of those deep slow brainwaves, but it's simply sedation.
The second problem with alcohol is that like caffeine, but through a different mechanism by way of acting on the sympathetic fight or flight branch of the nervous system, it will make you wake up more times throughout the night. And once again, they're so brief that you don't usually commit it to memory.
The other thing is that because of that sleep fragmentation, that principally is happening in the first half of the night. This is why on your sleep tracker, when, you know, I'm, if I look at my O-ring data, I mean, I don't typically drink, but even if I have, you know, a glasses, I get hit, not just with this.
Another thing I'm going to tell you about REM sleep,

I lose a good amount of my deep sleep.

And it turns out that it's really the fragmentation

of your sleep early on in the night

when the alcohol concentration is highest,

when your liver and your kidneys

have not had the chance to metabolically clear it.

And when you get fragmentation

in the first half of the night,

you're not getting your deep sleep.

And as a result, there's a great study that demonstrated that alcohol after dinner, one glass, decreased the amount of deep sleep, and as a result, produced a 50% drop in growth hormone release. 50% I mean I don't know what you'd have to age an individual by and to get them to have a 50%

drop in growth hormone but so there are it's consequential it's not epiphenomenal just because you don't get deep sleep you may say well so yes and so what what's the consequence of that lack well one is that you don't get your growth hormone release for reparation repair but then the other thing about alcohol and people love me don don't they? Someone once told me when we listened to you, your personality is like the greatest prophylactic known to man. You're the fun police.
Thanks for, yeah, exactly. Yeah.
And that goes together already with my bloody acerbic personality. Anyway, nevertheless, alcohol also is very good at blocking your REM sleep.
And it turns out it's not the alcohol, it's the metabolic byproducts of it, particularly the aldehydes. And it's the aldehydes that will essentially act like a sort of jamming up of the cogs of the gears of the generation of REM sleep.
So you become REM sleep deficient. This is the reason that people will sometimes say, God, you know, we had two or three bottles of wine last night when friends came over at the weekend.
And then I slept in late because we went to bed late and I was having these crazy dreams, just wild crazy dreams. What's happened there is that firstly, REM sleep comes mostly in the second half of the night you get most of your deep sleep in the first half of the night if you're sleeping later into the morning that's the REM sleep rich phase part of your sleep cycle so your brain has a different taste preference for what it wants to eat from the finger buffet of the sleep menu at night early in the night all it wants to do is feast on deep sleep very little REM as you go through into the second half of the sleep menu at night.
Early in the night, all it wants to do is feast on deep sleep, very little REM.

As you go through into the second half of the night,

it likes to switch its taste preference to REM.

The further you sleep later into the morning,

the more REM sleep you get.

If you want to increase the amount of REM sleep,

one of the things you can do is just sleep

half an hour later into that morning

and you'll start to get more REM sleep.

But what alcohol will do is it will start to block the amount of REM sleep that you've been having for most of the night. Your brain is so clever though.
This sleep is so strongly conserved across biology, across phylogeny that sleep emerged, as I said, with living organisms and has stayed there. It's one of the most preserved behaviors that we see in any living organism.
And it's preserved at the level of the stages too. So your brain, what I mean by that is it's understanding how much REM sleep you, Chris, should have had across the night when you've had a few too many drinks.
And it keeps a clock counter of how much REM sleep you should have had and you've not obtained. And finally, by those late morning hours on the Saturday, when you've slept late, your liver and your kidneys have finally excreted all of the alcohol.
So in the last hour or two of sleep, your brain gets the REM sleep it will have normally obtained. Plus it tries to get back that which it's lost.
And it's called a REM sleep rebound effect. And that's why you have really intense dreaming and you have these really crazy, bizarre experiences.
Does your brain get back all of the REM sleep that it lost? No, it doesn't. It can only accumulate about 50% of the debt.
So you will still be REM sleep deficient. REM sleep, it turns out, if you want to say, give the head to head challenge, which is more important non-rem versus rem well i'm going to firstly tell you that all stages of sleep are important different stages do different things at different times of night but the ultimate test of what's more important is presumably death how quickly do you die when you don't have one versus the other.
They did a series of studies back in the 1980s that will never be replicated again because I think they were just, you know, so barbaric. They started to sleep deprive rats to the point when they died.
And what they found is firstly that rats will die as quickly of food deprivation as they will have sleep deprivation. Sleep deprivation will kill you just as quickly as no food, about 11 days in the rats.
Then they said, okay, let me now selectively just deprive the rats of deep sleep. So they still get REM sleep or they get deep sleep and we remove REM sleep.
And when they looked at that, the rats died from REM sleep after about 20 days. So REM sleep was, you know, still lethal.
A lack of REM sleep was still lethal. Non-REM sleep, they still died, but they died after about 60 days.
So in other words, rats will die quicker from REM sleep deprivation than they will from deep non-REM sleep deprivation.

We all predicted the opposite in those studies. Why? Because I told you that non-REM sleep was the original OG in terms of the evolutionary course of sleep.
It was the first stage of sleep. So surely the first stage of sleep that emerged in the course of evolution would be the fundamental, elemental, most important.
The opposite was true. Great study then back at Harvard.
And what we find is that a lack of sleep, short sleep, as I said, shorter your sleep, shorter your life. And it's sort of a, it's a, it's a decaying curve, which is that, you know, the less sleep that you have, the higher and higher your death risk.
But let's come back to that seven to nine hours of sweet spot because something odd happens. When you get past about nine, your death risk does not keep going down.
It goes back up as if more sleep after nine hours is deathly. And people have said, well, that's proof that sleep can actually kill you.
If you look at the data, at least one of two things is happening in those studies. When you get sick, what is the first thing that you typically want to do? Sleep.
Exactly. And it turns out that the reason is that your immune system has a very adaptive network that when you get sick, it brute forces a set of chemicals to induce you into more sleep because it knows that the Swiss army knife of health, the best thing that it has to combat disease and sickness is this thing called sleep.
So it drives you to sleep more. And so what was happening in those studies is that whatever the disease was, the sickest people were sleeping more.
It's like an unhealthy user bias. And it looks like artificially more sleep is killing you.
It's just that the people that were sleeping nine hours or more per night, there was something underlying that was causing them to. It was too powerful for sleep to overcome despite sleep trying.
The other reason is because of sleep quality versus quantity. Typically what we find is that people who have really bad sleep quality stay in bed for far longer and sleep quality also predicts all cause mortality.
So as a consequence, it looks like people, when they say, what time did you get into bed? What time did you wake up's how they measure the that the amount of sleep as it were poorly as it is those people who were in bed for 10 hours died sooner and the reason is not because they were sleeping 10 hours it's because they were trying to get back more sleep because the quality of their sleep was so bad that they had to stay in bed for longer and therefore poor quality of sleep masquerades as longer quantity of sleep being bad for you. But to come back to it, this Harvard study then looked at how much of different stages of sleep people were getting across the lifespan because they were able to do this with fancy sort of technology.
And what they found was that when they put non-REM sleep, again, in the same statistical model with REM sleep, REM sleep beat out deep non-REM sleep in humans to predict your all-cause mortality. And here, it wasn't this reverse J-shape, like total sleep duration, which is, you know, once you get past nine hours, it starts to hook back up.
No, with REM sleep, the less and less that you had, the worse and worse your mortality risk. It was a linear relationship.
And so across animals, across human beings, REM sleep seems to have been, if you want to do the math, which I wouldn't argue for anyone to do, if there is one stage of sleep that's mortality more important than the other, it would be REM sleep, which is also the reason maybe to raise caution regarding alcohol and then maybe THC. Talk to me about CBD, THC.
It's been marketed for a while separately and together as solutions. What's the truth behind it?

So THC and CBD, I think they've gone through a real evolution.

THC, for the most part, I think the data is fairly robust.

It's just not going to be your friend when it comes to sleep.

It is very clearly helping people fall asleep faster.

And I think that's something that we can come back to in a second.

The problem with THC is that the problem with TH a second. The problem with THC first is that you build up a tolerance and a dependence on it, a psychological dependence.
And what happens is that when you stop using THC for sleep, not only do you go back to the bad sleep that you are having because of the dependency, you typically have a withdrawal and your sleep is even worse as a consequence. And if you look at the number one reason why people fail in their attempted abstinence from smoking weed, it's because they can't tolerate the insomnia.
So they fall off the wagon and they go right back to using again because they've built up both a physiological and a psychological dependence so that's the first issue is just the really bad insomnia in fact it's part of the cannabis withdrawal syndrome set of features in what we call the dsm-5 which is the diagnostic and statistical manual of mental disorders it's the psychiatrist's handbook. If you look at cannabis withdrawal syndrome, right there at the top is insomnia.
And you're just feeding yourself a future event in your history of insomnia when you try to withdraw and you typically will go back. The second problem with THC is that it's very potent at blocking your REM sleep again.
And we've spoken about REM sleep both as a mortality feature. REM sleep is critical for creativity, learning, and memory.
It's also essential for your emotional and mental health. But we often think of dream sleep, you know, it's It's such an active state that we think of it as purely for the brain.
REM sleep is for the body. Men and women both release their peak levels of testosterone when you're in REM sleep.
And so REM sleep is essential, but you're depriving yourself of it with THC. And a really good case in point here is that when people stop using THC, when they've been smoking weed, firstly, they'll start to say, I just don't dream or I don't remember my dreams anymore.
Then all of a sudden, when they stop using it, they will say once again, like that late morning, Saturday morning with the alcohol, they will say, I'm just having these crazy dreams now. I never used to dream at all.
The reason is because the brain has built up such a chronic debt of absent REM sleep that finally when you stop smoking weed, it comes back with a vengeance because you've been trying to sort of get it, but you can't. And the roadblock is finally out the way.
And boy, do you start getting REM sleep again. So THC, right now, I just don't think there's good evidence for, although I'll come back to it now in one of the two ways.
If you look at some of those studies, though, and you've really got to kind of dig deep into them and look at all of the ancillary, the supplemental materials in the science paper, something funny happened when I was reading the literature. If you looked at, they always classify people's level of sleep apnea in these sleep studies.
It's just one of the things that we always measure, just like we measure your brainwaves and we measure your sleep apnea. If you look across when people were dosed experimentally with THC, the sleep apnea started to decrease.
And in some of those studies decreased statistically significantly, which would argue that THC may potentially be, have something beneficial to say about being at least an adjunct to sleep apnea therapy. Now, I am not going to advocate based on the downsides that come with THC in terms of your sleep that it should be used, but nevertheless, you shouldn't throw the baby out with the sleep bath water here.
What is it about THC that is beneficial to reducing the respiratory disturbance associated with sleep apnea? I think we need to figure that out because there are too many studies where that seems to be an anecdotal result in the data. Now, is it because it prevents the relaxation response of the airways so that they stay more taut and resistant against the collapse.
Is it about the release of certain neurochemicals that are there to stimulate the nerves to keep the air? I've got no idea, but I do think it's a really interesting kind of story that's yet to be told. What about melatonin, other sleep supplements that people are probably quite heavily relying on? Interesting.
I mean, you'll know this being from the UK, but Americans may not. Melatonin, something that you can just buy in CVS here, is kind of hard to get a prescription for in the UK.
Drugs like Zolpidem, Ambien. uh the you do not mean, you need to be like fucking insomniac for weeks and weeks in order for your doctor to step in pharmacologically and help you with your sleep in the UK.
It's very much not a thing that your GP would ever do. But some people from the UK can get a hold of melatonin in some way or another, especially a lot of people in America are using it.
And other supplements, the magnesiums of the world, what's the L-theanines, what do you sort of come to think about here? Yeah, I think the first thing to note is that if any of these supplements or any supplement stacks that are out there that promise you the royal road to resplendent sleep, if they really were doing what

they claim, the drug companies would have been all over them 20 years ago and would

find analogs and would have been making billions of dollars from them.

The fact that they've left them to the wayside tells you a lot about really what their efficacy

is.

And the drug companies are ruthless, but it took George Lucas, I think, something

Thank you. to the wayside tells you a lot about really what their efficacy is and the drug companies are ruthless but you know it it it took george lucas i think something like 30 or 40 years to amass about 4 billion in profit from the star wars franchise took ambien 21 months to do that so they know that these drugs if they are out there and any molecules like these, if they are good sleep aids, they will be very strategic.
Melatonin, I think certainly over here, it's so easily purchased. You go down, you know, any grocery store and in the health food section, there's this big purple subsection and that's the melatonin section.
And you've got, you know, 10 milligrams, 20 milligrams. I've seen 50 milligrams.
Firstly, five milligrams, 10, 20 milligrams, these are what we call supra-physiological doses, meaning that they are levels of melatonin that your body would never naturally release far higher than your body's natural tendency. So the fear here, although there are some studies that people have argued, this is not the case, but the fear is just like testosterone replacement, at some point your testes, if you're exogenously injecting, will just stop producing innate testosterone.
And once they stop, they don't restart. The worry is the same with your pineal gland, which is going to release melatonin, that if you keep exogenously giving your brain vast amounts, it says, well, you're giving it to me, so I don't need to produce it anymore.
And once it stops, does it ever restart? There are some data where they looked at an individual who was blind. And the reason that they were looking at this individual is because when you're blind, and depending on the level of blindness, if it's at, let's say, the level of the retina or the optic nerve, you don't receive light signals.
So you don't get the light to reset your circadian rhythm. So you're bouncing with your sleep all over the place.
It's very difficult for these patients. So what we typically do is we give them exogenous melatonin to at least feed them the signal of melatonin darkness at night to try to regulate their sleep.
And they did a study where they were tracking the melatonin of this individual and they were giving exogenous melatonin. And then they stopped and then looked to see, did that individual stop producing their own natural melatonin? And the answer was no.
So people will say, well, that's a good demo. And it was about a 30-day experiment.
Other people, I think, have looked across about six weeks of dosing. And when they stop, the people keep producing it.
And some people have argued that's the evidence then that we don't have to worry about that. The problem is most people don't use melatonin like that.
They've been using it for three or four years. So we don't know.
And it could be perfectly harmless. The second concern about melatonin is that it's a hormone that regulates the timing signal for when you should sleep.
It doesn't participate in the generation of sleep itself. So melatonin is like the starting official at the hundred meter race.
It brings all of the sleep races to the line and begins the great sleep race but it doesn't participate in the sleep race itself that's a different set of chemicals and compounds so that's why when people have done what we call meta analyses where you get all of the individual studies looking at melatonin and sleep and you put them all together in the same big statistical and you ask, what's the overall effect? Melatonin only improved the speed with which you fell asleep by about 3.9 minutes, which is not that much more relative to placebo. And it only improved your sleep efficiency by about 2.2%.
So again, largely trivial. Now, I think, however, despite touting that those statistics i think there is a subset of people for whom melatonin is sleep generating and therefore melatonin is not just the starting official it's also one of the racers and we don't yet understand why i think one of the ways that melatonin could be a sleep generating agent, and this will

bring me back to CBD in a second, is that melatonin can make you cold.

Melatonin has the ability to produce not hypothermia, don't worry about that, but it

will drop your core body temperature a little bit.

And it turns out that we do need to drop our brain and core body temperature by about one degree Celsius to fall asleep and stay asleep. It's a reason that it's so hard on those summer nights when it's brutally hot and you've got no air conditioning, you can almost not fall asleep despite how tired you are in a warm room.
But in a cold room, you typically can sleep. It's always because the cold room is at least taking you in the right temperature direction for good sleep as melatonin in some individuals may be mildly hypothermic and move you in that direction.
So I think that's, I'm fascinated by that. And I want to pick that apart, but for most people, firstly, it's not going to move the needle.
That's the reason that no one, no doctor has ever prescribed melatonin for people with insomnia. You have to have a circadian disruptive clinical syndrome causing the insomnia to receive melatonin.
That's where it can be helpful. The other thing about, or two other things about melatonin, if you could go down that purple aisle, now a large part of it is dedicated to pediatric melatonin for kids.
And what we know is that melatonin is a bioactive hormone. We did some work and we were looking at great scientist, Craig Canapari at Yale, and we spoke with the FDA about this.
Admissions to the hospital for melatonin poisonous overdose have increased by 503% in the past 10 years, which is a stunning statistic.

now granted melatonin for the most part is a largely inert compound in terms of its safety profile but the worry with the pediatric component of melatonin nowadays from the

community is that studies done back in the 1980s, 70s, demonstrated that in juvenile male rats, essentially male rats going through adolescence, when they were given higher doses of melatonin, it stunted their testicular growth and it caused testicular atrophy. So imagine if I came along to a PTA

meeting, a parent teacher association meeting, and to the parents and the teachers, I got up there

and said, tonight, I'd like you to start dosing your child with bioactive hormone. And I'd like

you to dose them with a magnitude that is far higher than their bodies would ever naturally

release. And it's a hormone that will also disrupt their reproductive gonadal development.
And I'd like you to do this every night for the next couple of years. Who's with me? And you get taken off stage rather rapidly.
And again, I don't mean that that's hyperbolic in terms of an example, but I do think we need

to be a bit more thoughtful, certainly about melatonin in pediatric populations. The final thing about melatonin, it's now been replicated.
They did a study originally where they looked at at least 20 different brands off the shelf of melatonin, and then they test it based on what it said on the bottle versus what was inside the capsules. what it turned out was actually what you were swallowing swallowing was anywhere between 83 less than what it said was on the bottle to 464 more oh fucking hell right so that 50 that 50 milligram capsule has become a monster it's a wild west you don't know what you think because it's not regulated by the fda over here wow and what was even worse is that within any one vendor the amount of variability from one batch to the next the next was just as large so this isn't across even across companies what about other technologies to artificially boost or improve sleep is there anything cool at the moment yeah i think I mean, I think there are, you know, CBD, I think is actually one of the potential contenders in this category of new emerging technologies pharmacologically.
CBD, I think, is, we still don't have enough data. I think the problem with CBD is that it is dose dependent.
If you look at the data, squint your eyes because there's not enough, and you make a non-scientific kind of guesstimation, anything less than about 25 milligrams seems to actually be wake promoting. Whereas anything that's about 50 milligrams or more may actually be sleep promoting.
Even though it's the same drug. Compound.
Same compound. So you get what's called a dose dependent response and it's bimodal, meaning that it's the Goldilocks phenomenon, you know, not too little, not too much, just the right amount.
And let's then entertain that you and I sit here in another five years time. There's been lots of work on this and CBD now is a sleep aid at the right dose.
The question then is how is it doing that? Because for me as a scientist to entertain its causality, I at least want to understand mechanistically what it's doing to be a plausible parsimonious explanation. For CBD, I think it's actually at least two different routes.

Like melatonin, CBD is really quite hypothermic. It will get rats cold when we dose them.
The colder their core body temperature, the faster sleep will arrive with them, the deeper the sleep that comes after. The second, however, I think is an indirect mechanism.
I think now there is very good data, even human brain imaging data, that CBD is what we call anxiolytic, which it reduces down your anxiety. It takes you out of that fight or flight branch that we've been talking about.
It reduces cortisol levels. The emotional centers in the brain called the amygdala, they are turned down in terms of their volume of kind of cranked activation by way of CBD.
So in other words, that kind of tired but wired phenomenon is potentially going to be medicated by CBD. CBD isn't necessarily generating sleep.
It's simply removing what is blocking your brain's natural ability to generate the sleep that it could do, if only it could try to reduce the anxiety that's getting in the way. And when I say anxiety here, I'm meaning the physiological, biological anxiety within the body.
That's, I think, what CBD is potentially doing to get you into good sleep. So new technologies, I think CBD is an interesting one.
but then we come on to an area that I've been doing a fair amount of work in over the past eight years or so, which is the artificial enhancement of human sleep. Because what I started to realize is that, you know, I can come on lots of podcasts, I can give you the scientific data, but in truth, there's only so much I can do to get people sleeping the same amount that I would wish them to sleep.
So the next question would then be, well, could I create technologies that act like a zip file for sleep that I can compress sleep into six down from eight? Now, I think that that's, you've got to, I think it's a dangerous thing because I think it's hubristic because it took mother nature 3.6 million years to put this thing called the seven to nine hour sleep necessity in place. Sleep is the most idiotic thing that you can conceive of.
You're not finding a mate, you're not foraging for food, you're not reproducing, you're not caring for your young and you are vulnerable to predation on any one of those grounds. Sleep should have been strongly selected against in the course of evolution.
If mother nature had found some magical zip file solution to compress eight hours of vulnerability nonsense down to six guaranteed, she would have done it. And the fact that it hasn't emerged.
And then I come along and I say to you, oh, Chris, I'm going to be, you know, some, you know, scientific genius who comes along with the compression zip file for sleep, you know, good luck, take care. We are starting to get there with some things though.
One of the things that we developed was an electrical brain stimulation device. So we've moved from pharmaceuticals to electroceuticals, because if you want to change sleep, sleep is an electrical phenomenon.
It's an electrophysiological state. It's brainwave activity.
It's electrical activity. And if you want to speak in the currency of the brain, you should deal in the same currency, which is electricity.
So we developed something called a transcranial direct current stimulation tool, which is a fancy way of saying, I put a headband on and I insert a small amount of voltage into your brain. It's so small you typically don't feel it, but it has a measurable benefit to your brain wave activity.
And people had been doing this approach where they measure your sleep in the laboratory and they're starting to look at these deep slow brain waves and then using this electrical stimulation device they're going to try to act like a choir to a flagging lead vocalist and by way of measuring it they can try to predict where the next stroke of midnight is coming on the top of that brain wave and they hit you with a pulse of electricity and they try to amplify the size of those brainwaves and they can and in doing it they almost double the amount of memory benefit that you get from sleep the problem is when we go to sleep we take things off we don't put things on so you're expecting me to have a headband device with all of these wires and i'm going to sleep with it. And then there's going to be some crazy computer in your study that's kind of, you know, measuring your brainwave and it's trying to temporally estimate when that's a disaster.
It was never going to happen. So what we took the approach of is that when you stimulate the brain and you stop stimulating like a drug in the system, it still has a blast radius of a benefit.
And when we do 10 minutes version of stimulation, it lasts in terms of its effect on the brain for about two hours. And it was that deep sleep that I said comes in the first half of the night and mostly in the first two hours.
So I knew I had this window of opportunity to capture to go after deep sleep. So instead, what we did was we applied this headband.
And as you're brushing your teeth, when you're taking your makeup off, you you're stimulating the head or you're lying in bed for 10 minutes. And then what happens is that you take the headband off and it's almost like, um, it's a good analogy would be a child on a swing.
They're, they're static and they're swinging their feet nothing is happening you as the parent you've got to come along and you've got to start swinging them but when you give them enough momentum at some point you stop and they keep swinging so i was trying to essentially get the brain swinging so that when it went into sleep it would generate bigger or a better analogy would be i'm trying to fertilize the, I'm trying to electrically fertilize the soil of your prefrontal cortex so that when I take it off and you start sleeping, you germinate more powerful deep sleep brainwaves because I've electrically fertilized the soil. Have you tested this in the lab? So we've tested it now multiple times and we were able to, we've published data data on it already we then ended up realizing look if i'm going to get this out to the public despite me being a puritanical scientist i've got to make it a company and move it out we got venture-backed capital that was just when covid hit and we were trying to do human testing where we were putting you know nasal thermistors up people's noses to measure their breath and And COVID, you know, so we had the kind of caboose, but not a kibosh.
Anyway, one of those, we slowed down, but we were able to get enough data that at least confirmed to me that it had efficacy. We've released a first-gen product now.
Again, I'm not some, I never want to be the George Foreman grill of sleep.

You know, I never want to hawk this stuff.

So you can kind of look around.

What's it called?

It's called Somni.

So if you just go to the website, Stim Science, the company is Stim Science, Stimulation Science,

Stimscience.com, you'll find it.

Take what I say with a grain of salt.

It's Gen 1. If it were up to me, I would wait at least another 10 years, get another 10 million hours of data before I, as a scientist, felt comfortable.
That's the reason I'm not the CEO, because people will have already done this long before me. So we've got a first-gen product out there.
Second-gen is coming, I think, probably the end of Q1 2025. We've now done lots of systematic studies.
We've looked at it on the basis of insomnia. It seems to be even more efficacious for the more severe your insomnia symptoms are.
I was worried it would be the opposite. The harder the problem, the less potent the solution.
It seems to be the opposite. It does seem to benefit young and old, but I would say that in the especially old individuals,

we're finding it harder to drive the brain into sleep

with the stimulation device.

We now, I think, have some good new solutions

in terms of how we stimulate the brain

to overcome the age-related problem.

So it's not all good news,

but certainly the duration of sleep

and the efficiency of sleep improve and the speed with which you fall asleep. How long do you have to have it on for? About 10 minutes.
Wow. And it's an interactive thing because we'll also do, um, bone conduction for sound.
So you have a whole app experience, you do the app and what's different in our method versus others who are trying to do this is what's called it's a closed loop system because the stimulation i need to co-opt my brain into sleep is slightly different in terms of its frequency in other words what how i'm stimulating your brain in terms of the kind of the brainwave pattern my stimulation frequency sweet spot is different to not by much, but just enough that if I tailor it to your unique frequency snowflake, like as if versus standard stimulation tools out there are like going to your Bloomingdale's and you just grab a suit off the rack and it doesn't really fit you quite well. This version is the Savile Row suit tailor it unique to your physiology and that turns out to make night and day night and day difference it makes a big difference statistically in fact we almost get no benefit at one size fits all stimulation and we were doing that for about two years and getting no data and I didn't't want to release the product because, you know, I don't want to sell snake oil.
If my mother is buying a device that promises a good sleep and it's $400, that I'm not going to sleep well at night if it's total snake oil. So we just weren't going to release.
And then we realized, no, we've got to find a unique stimulation pattern. So what the headband does is not just stimulate, it records.
It's an input-output device. And we start with a short session where I measure your resting brainwave activity.
And then we do a sort of an AI calculation where we rejig the stimulation for your frequency. In reverse.
Yeah, we reverse engineer it. And now we know what to stimulate you at.
And then if we see your brainwaves change, even across the 10 minute session, we're constantly adapting it to what we call a staircase method. Very cool.
So that's electrical stimulation is one path. I think I'm now interested in others.
The next one is kinesthetic vibration. If you see a parent with a child who's not sleeping well, typically, you know, a grandmother will just pick the child up in their arms and they'll start to do what? Start to rock the child.
You know, you think about, you know, a manger, rocking the manger or parents with their child, they'll put them in the car and anything that's repetitive kinesthetic is enough to induce sleep. So they did this great study, Sophie Schwartz at the University of Geneva.
It was wonderful borderline S&M. They got a mattress frame and they dangled it on these big chains from the ceiling.
So the bed frame was suspended on these chains. And all of a sudden it feels like, you know, candle wax on the nipples, tie me up, tie me down type stuff.
And then what they did was they inserted an arm against the side of the bed frame that had this rotation. And it would rock at a very slow frequency.
In fact, it would rock only once every four seconds. It was a really slow rock.
And the reason they were doing that is they were trying to mimic the super slow brainwave frequencies that go up and down, maybe just once every second, maybe once every two seconds, ultra slow brain. They were trying to mimic that.
And sure enough, by rocking you at this gentle frequency, it increased the amount of those deep sleep brainwaves and these additional bursts of brainwaves that ride on top of them like surfers on a wave called sleep spindles. And the combination of those two we know are important to hit the save button on new memories for what we call memory consolidation and sure enough after the sleep on the rocking mattress it ended up boosting the amount of memory by about 20 and some of their replication studies by about 10 you think 10 but if I were to say to one of my students,

you know, okay, look, you got, you know, 65% on your exam. Do you want an extra 10%? Oh my goodness, that's a great point.
You know, so it's not, it's not a trivial amount. So I think this, and then they've done these really great studies in, in fruit flies where they started to just vibrate the surface and these fruit flies just conked out.
And there's something about the kinesthetic motion. And then what they did was really clever.
You could say, well, is it something to do with the tactile sensation of feeling like you're moving? Or is it really what we call the vestibular system, the sensation of movement. So in these fruit flies, they were able to inactivate the vestibular mechanism in the fruit flies.
So the fruit flies could no longer sense movement and they vibrated them and they just stayed awake. So it absolutely is something to do with the vestibular system that is assisting with sleep so i think that's a fascinating area that you know these new mattress companies you know there are a couple of them bright b-r-y-t-e is doing this um eight sleep has you know the ability to now you know it will vibrate you can tap on the side of the bed andrate.
You know, what if, and take, by the way, I think Eight Sleep is a fantastic product. I was using it for years beforehand.
Now, together with myself, Andrew Huberman and Peter Atiyah, we joined the advisory board. So again, full disclaimer, take what I say with a grain of salt, just like I speak about Oura Ring because I'm an advisor there too.
I would say though that these mattresses may now be able to create some kind of ripple approach. And so we're starting to play with this technology in the lab where we're trying to do just lateral ripples to see if we can actually manipulate you.
I was at a conference at what's called the section of the advanced sort of science agency here, DARPA, which is part of the defense agency. And they had this really interesting technology for special operatives to navigate them through, based on the trajectory, through a particular kind of scenario where they had to go and find a kill.
And they couldn't use radio communication because that would give give the game away but they were able to insert this device into the ear that would stimulate the vestibular system and tell them left right forward back so then i was thinking well hang on a second if i'm rippling the bed or i'm swinging it you know all of a sudden my girlfriend and my wife is probably thinking geez you know it's a bit too much too soon you know we we were fairly pedestrian and what was going on in the bedroom now you're swinging the mat you know go easy i don't like that but what if i could not even stimulate your mattress which could disrupt some someone else all i need to do is have this ear device and i'm going to fool artificially your brain into thinking that it's being rocked by way of stimulating the vestibular system and off you go into sleep. So that's another sort of method that I'm really interested in.
And there's good evidence for. Probably the next one is acoustic.
And there's now, I think, this emerging wave of acoustosuticals, which is acoustic manipulation of the brain. Early studies from groups in Japan, like from Germany, Jan Born's group, they were just simply trying to do sounds that were these tones that would go at the frequency of the slow brainwaves.
And they just started playing them as you were falling asleep and just kept playing them. And they were ignorant of whether your brainwaves were going up or down.
And it did seem to improve the amount of deep sleep, just passive tone playing at this frequency of about once every second or less. Then they got a bit clever.
Then they started to measure the brainwaves in the laboratory and they would try to hit the brain with a tone right at that strike of midnight, like we were doing with electricity. And sure enough, you boosted the brainwave.
The problem was if you did it about three or four times in a row, the brain fought back and it resisted the tone. And in fact, it started to decrease the amount of deep-sleared brainwaves.
So you've got to be a bit careful. Why would that happen? It's probably because the brain has a protective neural mechanism to prevent too much synchronous brainwave activity synchronous brainwave activity when it gets out of control is called epileptiform brainwave activity which causes a seizure so you've got to be you know you have to be thinking about these things so i think that but there is i think now devices out there that are doing vibratory stimulation and part of the brain stimulation device that we have now is a bone conduction system too where we can also vibrate you as well as electrical stimulate you because so you're doing both so i'm doing both because when it comes to sleep for a commercial device now as a scientific device i want to pass them out separately and i want to understand them distinctly but when it comes to the you know boots in the ground and the trenches i'm going to throw the kitchen sink at this too so if i can do acoustics and electrical i'll do it it's so cool all of this technology is so sick and uh yeah i wonder what's going to happen i wonder what's sort of coming next and obviously you know such a reliance on pharmaceuticals.
Yeah. Sort of leaning in and people manipulating all manner of different things internally.
You mentioned insomnia there. Have you looked at chronic fatigue syndrome? Is that part of your remit at all? Fatigue sounds like tiredness, sounds like sleep.
Is that something that you guys ever cross over with? We've done a little work in it and it's different. And I think what's happening with chronic fatigue is that there is, here we're talking about a metabolic problem, which is it's about energy balance, that there's something going on with a metabolic regulation of the system that causes this overall sense of malaise.
Now, how that plays out with sleep, all we simply know is that chronic fatigue syndrome results in fragmented sleep and poor quality of sleep, which in some ways is counterintuitive because all of us, if you've ever gone out, you know, on one of the, you know, I cycle for a bit. If I've gone on one of those, you know, century rides and, you know, back in California, I like to do it in the summer because I love cycling in the heat.
By the end of that day, I come home and it's like working in the fields for eight or nine hours. I just know that night

I am going to have the most righteous sleep of my life because I'm just so fatigued. I can feel it

in my body. That's a very different physiological state, I believe, than chronic fatigue syndrome.

Mine is acute fatigue syndrome.

Chronic fatigue syndrome, I think, is probably a very different biological cascade.

And that's probably pushing you into more, perhaps, a higher kind of chronic cortisol

state where you're all of a sudden fighting against sleep rather than promoting sleep. I think it's different.
Fascinating. You said earlier on as well about dreaming.
I want to kind of get into dreaming. What is it? Why do we do it? How does it work? Explain to me.
Yeah. Dreaming is, when you think about it, absolutely bizarre because last last night, everyone listening, yourself included, as long as you slept, you all became flagrantly psychotic.
And before you reject my diagnosis of your nightly psychosis, I'll give you five good reasons. Firstly, when you slept and you started to dream, you started to see things which were not there.
So you were hallucinating. Second, you believe things that could not possibly be true.
So you were delusional. Third, you became confused about time and place and person.
And in psychiatry, that's what we call being disoriented. Fourth, you had wildly fluctuating emotions.
And we describe that as becoming emotionally labile, you're pendulum-like, you're all over the place. And then fifth, you woke up this morning and you forgot most, if not all of that dream experience, you're suffering from amnesia.
If you were to experience any one of those five symptoms while you're awake, you'd probably be seeking psychiatric and psychological intervention. But for reasons that now we're starting to understand, it's a normal biological and psychological process.
So if it's prevalent and it's consistent, what is it functionally doing for us? Now, you've got to be very careful because dreaming, for the most part, is principally associated with REM sleep. So how do I put a scalpel scientifically between simply conflating any function of REM sleep, let's say hormone benefits for testosterone, and saying, no, separate from REM sleep, separate from the stage of sleep from which dreaming emerges, show me that dreaming above and beyond the state from which it comes from, which is REM, also has its own separate functional benefits.
And that was hard to do for a long time. And now we know that there are two benefits of dreaming, independent of necessarily having REM sleep, although it is beneficially supported by the physiology of REM sleep.

The first is that dreaming provides a form of overnight therapy.

Dreaming is emotional first aid because it's during dream sleep at night that dreaming acts like a nocturnal soothing balm that just takes the sharp edges off those difficult, painful experiences so that you come back the next day and you feel better about them. And what REM sleep dreaming is doing is essentially it's divorcing the emotion from the memory experience.

Because what makes a memory emotional is that at the time of the experience,

you had this whole visceral emotional reaction,

and that wraps the memory with this emotional blanket.

But what dreaming does is it goes in there and it divorces the emotion from the memory.

It strips the bitter rind from the informational orange so that you wake up the next day and you have a memory of an emotional event, but it's no longer emotional itself. You don't regurgitate the same intensity of visceral reaction that you did at the time of the experience.
And so that's why we think dreaming provides a form of, it's emotional convalescence. And the quintessential disorder that we've studied, that this process seems to fail in, is PTSD, post-traumatic stress disorder.
Because you speak to those patients what they will tell you

is i can't quote unquote get over the event what they mean is that every time that they relive the memory let's say it's the war veteran they're walking through the supermarket car park a car backfires and instantly have a flashback to the trauma memory of the detonation of the land mine And what they're describing to you is they have not stripped the emotion from the memory. It's still bound to the experience.
It's not coincidental that one of the diagnostic features of PTSD is repetitive nightmares. And what we've done is put forward a theory that in PTSD, because they have

two higher levels of a stress-related chemical called noradrenaline in the brain, they are not

able to do the elegant trick of stripping the emotion from the memory. So what happens? The

next night, the brain comes back and says, look, sleep, please. I've got this highly charged

emotional trauma memory. Please do your trick of divorcing the emotion from the memory.
And it fails again because of this two high levels of a stress chemical called noradrenaline. And so it becomes this repetitive, almost like a broken record.
And it perfectly fits the feature of repetitive nightmares. You cannot receive a diagnosis of PTSD without having sleep disturbance or repetitive nightmares.
So then you can ask, well, so then in normal REM sleep, why is it doing that? REM sleep is the only time during the 24-hour period where our brain shuts off this stress-related chemical called noradrenaline. The sister chemical in the body everyone has heard about, it's called adrenaline.
Upstairs in the brain, it's noradrenaline. And noradrenaline does lots of things, but one of the things it does is it gets released in rude amounts when you undergo one of these emotional experiences.
It's the thing that plants the red flag on the memory and says to the brain, this is priority. This was emotional.
This is important. And so it's useful to prioritize what gets remembered in the brain, but it's only useful to tag the memory initially as important.
It's not useful to hold onto the emotion and dream sleep provides that form of the emotional detox. So I presented this data at a conference, this theory that dream sleep strips the emotion from the memory because dream sleep is the only time when the brain has this perfect therapeutic chemical cocktail of shutting off noradrenaline.
And the brain actually has the emotional memory centers reactivated during dreaming. So you can reactivate the emotional memories, but you process them in a safe neurochemical environment.
But in PTSD, they'd already measured levels of noradrenaline, the cerebrospinal fluid, and found that they were excessively high. No wonder they couldn't strip the memory, the emotion from the memory.
And I was presenting this. And then in the afternoon session, a psychiatrist came along from Puget Sound.
He worked in the VA, the veterans system, and he was treating patients with PTSD and they, most of them had high blood pressure. So he was treating them with a generic drug called prazosin.
And the drug, it turns out, because it's the VA, it's cheap, it's generic, it crosses the blood-brain barrier. So it goes up into the brain.
And he was perplexed because his patients were coming back to them and their blood pressure was a little bit better, but they started saying to him, I'm not having the nightmares anymore and my symptoms are getting better. So I had a theory that was in search of clinical data.
He had clinical data that was in search of a theory. And it was one of those kind of hair on the back of your neck moment, standing up, raced to him afterwards, said, look, I've got to catch a flight back down to Berkeley.
I'm going to fly you down next week. We need to go out for dinner.
We need to speak about this. We started speaking about it.
He did clinical trials. It then became the only

VA approved medication for PTSD. There have been some failed replications with that medication.

I'll tell you that right now, but nevertheless, it is usually one of the first line medication

treatments now for PTSD veterans for nightmares. So that's the first benefit of dreaming.
I would say that you can then argue, well, how do you disentangle that from just REM sleep that they're getting? Rosalind Cartwright, who has now passed away, great sleep researcher back in the 1980s, was looking at her patients she was treating psychologically who were going through really tough experiences, bereavement, divorce, and they were very depressed. And around the time of those events, she was measuring their dreams, getting dream reports.
And then she did a follow-up study one year later, and about half of those patients had gained remission in terms of their depression. They'd got better.
The other half had not. So she then went back a year previous and looked at the dream reports and split them on the basis of those who ended up getting remission and improving versus those who didn't.
Both of those groups were getting REM sleep. Both of those groups were dreaming.
That was not the difference. The difference was that those people who got remission at the time of the event were dreaming about the experiences themselves.
Those people who had REM sleep, who were dreaming but didn't dream of the events that they were experiencing, did not gain remission. In other words, it's not just sufficient to have REM sleep.
It's not even sufficient to dream. You have to be dreaming about the difficult things that you're going through in order to get that overnight therapy benefit.
So that to me was a demonstration that it's something about the act of dreaming above and beyond the stage of sleep. Does that make some contorted sense? The second benefit of dreaming is very different.
It's creativity and ingenuity. Because during deep sleep, deep non-realm sleep, that's when the brain takes the new memories that you've formed and it cements them.
It sets them like amber, like a fly trapped in amber into your brain. It cements them into the architecture so that you don't forget.
So deep sleep hits the save button on individual memories. But memories that sit like isolate islands in your brain are largely useless because that's the old laptop.
Your laptop was even better at storing individual pieces of information than your brain ever was, but you're far more intelligent. Why? Because you don't just simply have isolate pieces of information.
Your brain richly interconnects them together. That's the difference between knowledge, which is remembering the facts versus wisdom, which is knowing what it all means when you put them together.
That is the purview of REM sleep. REM sleep takes those new memories and it acts almost like group therapy for memories.
Everyone gets a name badge and it forces you to now speak to the people, not at the front of the room that you think you've got the most obvious connection with you've already done that when you're awake seeking out the obvious obvious connections dream sleep forces you to go and speak to the people at the back of the room that you think you've got no association with whatsoever it turns out that you do it's a distant connection but it's a powerful one nonetheless because when you start to fuse things together that shouldn't normally go together, but when they do powerful one nonetheless. Because when you start to fuse things together

that shouldn't normally go together,

but when they do cause marked advances in evolutionary fitness,

it sounds like the biological basis of creativity.

That's what dream sleep is doing.

It's almost as though you wake up

with a revised mind-wide web of associations.

And it's during dream sleep and the act of dreaming itself

Thank you. you wake up with a revised mind-wide web of associations.
And it's during dream sleep and the act of dreaming itself that we, it's almost like memory pinball. You take what you've learned, bang, and you shoot it up into the cortex and you start bouncing it around and you test out what the connections are.
But the way the algorithm works during dreaming is different than wakefulness. Wakefulness is the Google search gone right.
You type in, you know, modern wisdom into the Google search and the first page all about you. Fantastic.
You go to page 20 and it's about a field hockey game in Utah. And you think, bloody, how? But if you read about it, all of a sudden you think, oh, oh, that's clever.
I can see why that's associated it's a diff it's a now you can have a thousand of those every night that are completely useless but all you need is one of those to make that advanced leap that's the novel difference between 2001 and space odyssey where they're banging bones around And then all of a sudden, one of them realizes, Christ, this thing is actually a weapon. It's not just a bone.
What does it mean if we keep dreaming about the same situation or the same person, people that have sort of consistent dreams with consistent characters or scenarios in? Yeah, repetitive dreaming and repetitive nightmares. Some of it, think from the PTSD literature is about trying to reprocess emotion and emotional experiences.
And something maladaptive short circuits that. So you keep trying to reprocess.
That's one theory. the other is that we we don't know if necessarily that's your brain simply trying to prioritize the memory circuit and it's saying that every night i want to etch and score that memory into the sort of the the neural circuit glass of the brain ever more strongly because it's important so one camp is it's maladaptive and it's a process failed.
The other is it's adaptive and it's just simply telling your brain, pointing you to saying, this is the important stuff. We're going to memorize it more.
I would say that for people who are undergoing sort of repetitive nightmares, we used to have no real good treatments for it. Now I spoke about prazosinin as one way that we've done this with PTSD patients, but there's now actually a very effective psychological treatment for nightmares.
And it's called I-image rehearsal therapy or I-R-T for short. And it comes back to, we made a discovery back in 2003.

What we found is that when you form a memory, that memory is fragile. And when you sleep, the brain fixates it.

So it's now stable and it's set and it's hard coded into the brain.

However, we then discovered that when you come back the next day, if you recollect,

if you reactivate

that memory again, it opens that memory back up to being fragile and susceptible to being

molded and changed.

And you think, well, why would you go through the act of cementing it only to basically

kind of undo that cementing process?

Think about a memory system.

Think about a Word document.

I type in the Word document and then I hit the save button, which is sleep.

I can't edit it. I want it to be flexible and your brain has that ability.
So the brain, every time you recollect a memory, you open it back up to change and then you modify it and then you sleep again and you re-consolidate the memory. This therapy took advantage of that.
So it had individuals who had repetitive painful nightmares and with a therapist, they simply rehearsed the trauma dream. Now, during the rehearsal, every time they brought back that memory to mind, by definition, it opened up that memory to being edited.
And with the therapist, they would convert the ending. So let's say that I was in a horrific car accident and the brakes failed and I went straight through the junction and I got sideswiped and it was a horrific car accident.
Well, now instead I'm coming up to the lights and I'm hitting the brake pedal. And in this new sort of rehearsal, they say, well, then you just reach down because it's a manual car and you just grab the handbrake and you pull it and gradually the car decelerates.
You move it to the side of the road and you avert the rewriting the memory and

you rewrite the memory and then you get them to sleep and now it reconsolidates the updated version and you have to do that though multiple times so you set the new scenario which is a neutral scenario you have them rehearse it every day you set a timer they do this and then over time you morph the memory and you now rewrite your history. And as you're doing that, night after night, what happens to the trauma dreams, the frequency of them decreases in proportion with the frequency of you repeating that every day.
Absolutely brilliant memory dynamics. So cool.
So cool. Matt, I feel like I could speak to you all day.
We need to, we need to bring this one into land, at least for the first one. You're so great.
And like I said before, you genuinely made a huge change. The, probably the single biggest lifestyle change that I made was after your first episode on Rogan.
So however long I live is at least in part due to, due to yourself. Well, I stand on the shoulders of all of my colleagues.
I think I did a pretty bad job when I first came out at communicating science. I think I was untrained.
I was dictatorial.

I was absolutist. Not because I wanted to be that way.
That's not my natural ilk. It was just

because I saw so much suffering happening by way of a lack of sleep. Steaming in with authority

sounds like a nice way to fix that. Right, exactly.
And I was so passionate about it. I came across

as almost adversarial. I probably caused as much insomnia by way of my ted talk you know it was called sleep is your superpower or something and people were saying it should have been called sleep or else dot dot dot you know and i feel bad about that but so i've i would say i'm now i'm a little less bad as a scientific communicator, but really all I'm doing is communicating the

science of all of my colleagues. I'm just in the privileged position of being the idiot with the

Bon Jovi, her style and the bad accent who's trying to communicate sleep science. But if I've done any

of that work, it's simply because I've communicated the science of others and for their efforts,

I'm immensely grateful. Thank you.
Matt, I appreciate you. Until next time, mate.

Next time. Take care.