Your Brain on Screens: Myths and Facts & How Your Body Keeps You Alive

Speaker 1 This is an Etsy holiday ad, but you won't hear any sleigh bells or classic carols. Instead, you'll hear something original.
The sound of an Etsy holiday, which sounds like this.

Speaker 1 Now that's special. Want to hear it again? Get original and affordable gifts from small shops on Etsy.
For gifts that say, I get you, shop Etsy. Tap the banner to shop now.

Speaker 2 Today on something you should know, how hunger affects what you buy. Not just groceries, everything you buy.
Then some facts and myths about screen time and video games.

Speaker 3 You know, there was a big concern for a while about violence in video games.

Speaker 3 Generally, the research does not support any long-term links between playing violent video games and violent or aggressive outcomes in the long term.

Speaker 2 Also, why listening to other people talk on their phones can drive you nuts and the amazing ways your body works, your heart, your immune system, your brain.

Speaker 5 Your brain washes itself at nighttime. There's been studies where they've watched people when they're going to sleep and they've seen pulses of cerebrospinal fluid going over the brain during sleep.

Speaker 5 They really think that this maintenance time of sleep helps remove bad things for your brain, toxin buildup.

Speaker 2 All this today on something you should know.

Speaker 2 I've learned from experience that hiring isn't easy, even when you know exactly who you're looking for.

Speaker 2 Running a business doesn't automatically make you good at hiring people. It's a skill and it takes time, sometimes too much time.
That's why I like Indeed.

Speaker 2 It makes the whole process faster and easier and the results are better. When it comes to hiring, Indeed is all you need.

Speaker 2 Instead of struggling to get your job post noticed, Indeed Sponsored Jobs helps you stand out. Your listing jumps right to the top of the page for the people you actually want to reach.

Speaker 2 And that saves you days, maybe weeks of waiting. And the numbers back it up.
According to Indeed Data, sponsored jobs posted directly on Indeed get 45% more applications than non-sponsored jobs.

Speaker 2 What I like most is there are no monthly subscriptions, no long-term contracts. You only pay for results.
And while I've been talking, 23 hires were made on Indeed worldwide it's that fast

Speaker 2 there's no need to wait any longer speed up your hiring right now with Indeed and listeners of this show will get a $75 sponsored job credit to get your jobs more visibility at indeed.com slash something

Speaker 2 just go to indeed.com slash something right now and support our show by saying you heard about Indeed on this podcast. Indeed.com/slash something.

Speaker 2 Terms and conditions apply. Hiring, Indeed, is all you need.

Speaker 2 Something you should know, fascinating intel, the world's top experts, and practical advice you can use in your life. Today, something you should know with Mike Carruthers.

Speaker 2 I think everybody knows that it's a bad idea to go grocery shopping when you're hungry because you're going to spend more money and buy more junk. But there's more to the story.

Speaker 2 Hi and welcome to this episode of Something You Should Know.

Speaker 2 Not only does research support the fact that grocery shopping when you're hungry will cause you to spend more money, you probably have personal experience in that regard.

Speaker 2 But it turns out that shopping for anything on an empty stomach is a bad idea.

Speaker 2 Researchers at the University of Minnesota found that hungry people spent 64% more money at the mall on anything than shoppers who were not hungry.

Speaker 2 Apparently, hunger kicks in that human desire to hunt and gather. And since few of us are hunting and gathering in the traditional sense, we go shopping instead.

Speaker 2 Also, be aware of the scent of cinnamon. It seems that that makes you want to spend more money.

Speaker 2 And if you're a woman, a University of Texas study found that women want to buy more stuff when they're ovulating so that's another time to avoid going shopping and that is something you should know

Speaker 2 a very big concern today is screen time how much time you or your kids have a computer or a tablet or a phone screen in front of your face and the assumption is that you're probably spending too much time looking at screens and what you really need to do is cut back and spend less time with screens.

Speaker 2 But what is too much time? What's the actual harm? Does screen time affect everyone the same way? What does the research say about how screen time impacts people?

Speaker 2 The answers to those questions just may surprise you. And here to reveal all this is Jacqueline Nisi.

Speaker 2 She is a psychologist and assistant professor at Brown University, and she writes a popular weekly newsletter called Techno Sapiens, which provides tips to manage your screen time.

Speaker 2 Jackie has published over 50 peer-reviewed publications related to technology use. She's testified before U.S.

Speaker 2 congressional and state legislative committees on issues surrounding technology and mental health. Hey, Jackie, welcome to Something You Should Know.

Speaker 3 Great. Thank you so much for having me.

Speaker 2 So you hear all the time, people talk about all the time about how we shouldn't be on screen so much, that, you know, get off your phone you're you're on your screens too much and all that because why because what do we know are the real risks the real dangers we hear it's bad but but i never hear like how exactly is it bad

Speaker 3 yeah yeah i mean i do think that there broadly is a very negative narrative when it comes to screen time. And I don't know if that is always warranted based on what we know from the research.

Speaker 3 What we actually know is that it's more of a mixed bag, right? Like the effects of screen time really depend on what's happening during that screen time and on who the person is.

Speaker 3 You know, people have very different reactions to the same experience on their screens. So there's a lot that goes into it.

Speaker 3 But when it comes to thinking about the risks of screen time, I would say there's two broad categories of risks.

Speaker 3 So one is just around the time spent and concerns that that time is getting in the way of other other things that are important for our well-being, whether that's spending time in person with friends or family or spending time outside, being physically active.

Speaker 3 When screen time starts to really get in the way of those things, then I think that that certainly can be a risk.

Speaker 3 The other category I would say is around the content we're seeing on our screens.

Speaker 3 We know that there's a lot happening. For example, when we're scrolling social media, there's a lot we see that maybe is not the best for our well-being, is maybe not making us feel our best.

Speaker 3 And so I think that's another risk as well.

Speaker 2 That's certainly true that if you're on your screen, you're not doing something else. And what else could you be doing?

Speaker 3 Exactly. Or maybe you are, but you're not really totally present in whatever that other thing is that you're doing.

Speaker 2 Well, there, there's a big problem because, you know, that drives me crazy and I'm sure it drives a lot of people crazy when

Speaker 2 you don't have someone's full attention when you're talking to them and they think it's fine for them to talk to you and be on their phone scrolling or texting to somebody else.

Speaker 2 I find that so rude, but

Speaker 2 it's not just rude. It's like, well, I guess it is just rude.
It's like, you're not important enough to get my undivided attention.

Speaker 3 Yeah, you know, it's funny. There's actually in the research, psychologists have kind of come up with all these different names for that exact phenomenon because it is so common.

Speaker 3 So, there's a word called technoference, meaning technology and interference.

Speaker 3 Typically, that's used in like parenting work, so where technology is really interfering with interactions that parents are having with their kids.

Speaker 3 And then there's another term that's kind of funny called fubbing, which is basically phone and snubbing,

Speaker 3 meaning typically used in more like partner and friend kind of research. So, thinking about when we're on our phones and in the presence of friends or partners.

Speaker 3 And that is in some ways, you know, we're snubbing them because we're not giving them our full attention. And there is some evidence that, you know, unsurprisingly, that that

Speaker 3 experience can have negative impacts on the relationship, on our sense of connection and relationship quality, but also on, you know, our mood and our well-being.

Speaker 3 I think we often think that spending that time on our screens is going to make us feel better or less bored or whatever it might be.

Speaker 3 But actually, it does tend to have a more negative impact on our mood.

Speaker 2 Well, I think everyone would agree with what you just said because there are times when everybody, I mean, probably even you,

Speaker 2 likes to just scroll mindlessly through some social media something for a few minutes.

Speaker 2 But it's like junk food. It doesn't satisfy anything other than in that very moment, but there's no other satisfaction to it.

Speaker 3 Yeah, there's an interesting study actually that came out last year, which I think really illustrates this.

Speaker 3 Where they were with college students and they essentially had college students in a waiting room, like waiting to what they thought was participate in the actual study.

Speaker 3 But they, half of the students, they had weight with their phones and half of them they had weight without their phones.

Speaker 3 And the students who didn't have their phones thought that they were going to feel worse, thought they were going to be bored.

Speaker 3 They thought it was going to be awkward, kind of waiting around all these other students with no distraction of their phones. But actually, in the end, unsurprisingly, they ended up feeling better.

Speaker 3 They ended up, you know, reporting better mood at the end of the study because they were ended up socializing with the people around them and weren't as distracted by their devices.

Speaker 3 So I think that what we think is going to feel good is not always the thing that ends up actually making us feel good.

Speaker 2 What did they do instead? Were they just sitting there with their thoughts or were they reading a book or what were they doing?

Speaker 3 No, yeah. So

Speaker 3 they provided some kind of entertainment for the students if they wanted it. You know, I remember this particular detail of this study is that

Speaker 3 they had a giant Jenga game in the room in case students wanted to play and some other stuff around. But for the most part, they were just waiting with

Speaker 3 other students. So I think it was more about the socializing where they ended up striking up conversations.

Speaker 2 Well, that's the thing is, is

Speaker 2 scrolling on your phone is a solitary activity. And you can see lots of people together, but they're all on their phones.

Speaker 2 And so they're not really together and taking advantage or getting the benefits from the socializing part of it. They might as well just be home in their room.

Speaker 3 Yeah. You know, one of the things that we know about

Speaker 3 screen time and phone phone use is that, you know, as I said before, I think there are ways that it can be done where it can promote our well-being and ways where it can really interfere with our well-being.

Speaker 3 And part of that, I think, really comes down to the social aspects. So if we're using,

Speaker 3 you know, our phones to promote connection.

Speaker 3 social connection, whether that's, you know, we're sending a text to a friend to check in on how they're doing, maybe we're sending someone a message to make plans to meet up, like those kinds of things obviously are

Speaker 3 are going to be good, are going to make us feel better. But if we're using our phones in ways that are interfering with social connection, whether that's, you know, we're

Speaker 3 sitting on our phone, scrolling and looking at how much fun everyone else is having on social media, or we're sitting on our phones when we should be interacting with the people around us, those kinds of activities are going to have a more negative impact.

Speaker 2 You know, I'm really curious to know, because we often talk about how other people inappropriately use their phone or they're on screens too much.

Speaker 2 But how do people feel about their own use of screens and their own time on the phone? Do they think, yeah, I probably am on it too much, but, or do they think, no, I've got this under control.

Speaker 2 It's other people who have the problem. How do people feel about their own participation in this?

Speaker 3 That's a good question. My sense from the research is that there's certainly a good portion of people, I think probably the majority of people, who feel like they spend too much time on their screens.

Speaker 3 I think that that's a pretty common experience. Of course, there are plenty of people out there who feel good about their screen use.

Speaker 3 But I do think it's common for people to feel like they are spending too much time and to, you know, not be not be happy about that.

Speaker 2 And yet.

Speaker 2 probably don't do much to remedy a concern that they admit they have.

Speaker 3 Yeah, you know, I think that part of what makes this so challenging is that,

Speaker 3 you know, the screens that we're using right now, phones, in particular, smartphones,

Speaker 3 in many cases, the apps we're using on those smartphones, are really designed to attract our attention, like to be hard to put down. Right.
Like we

Speaker 3 know that there are features of our devices like notifications, which sort of ping and remind us to come back to them.

Speaker 3 Or if we're on social media, media, something like an endless scroll where there's a social media feed, there's no end to the feed, and so it makes us just want to keep going.

Speaker 3 These kinds of things really make it so that we are inclined to use our devices more.

Speaker 2 I want to ask you if you think that we're at the point now where

Speaker 2 phones, screens are becoming, I don't know, a crutch or a habit, maybe. I'm speaking with Jackie Nisi.

Speaker 2 She is a psychologist and assistant professor at Brown University, and she writes the weekly newsletter, Techno Sapiens.

Speaker 2 It's time for Black Friday, Dell Technology's biggest sale of the year. That's right.
You'll find huge savings on select Dell PCs, like the Dell 16 Plus with Intel Core Ultra processors.

Speaker 2 And with built-in advanced AI features, it's the PC that helps you do more faster.

Speaker 2 From smarter multitasking to extended battery life, these PCs get the busy work done so you can focus on what matters most to you.

Speaker 2 Plus, earn Dell rewards and enjoy many other benefits like free shipping, expert support, price match guarantee, and flexible financing options.

Speaker 2 They also have the biggest deals on accessories that pair perfectly with your Dell PC, improving the way you work, play, and connect.

Speaker 2 Whether you just started holiday shopping or you're just finishing up, these PCs and accessories make perfect gifts for everyone on your list. Shop now at dell.com slash deals and don't miss out.

Speaker 2 That's dell.com slash deals.

Speaker 2 With the weather getting colder and the holidays upon us, I just want my wardrobe to be easy. Things that look sharp, feel great, and last season after season.
which is exactly what I get from Quince.

Speaker 2 I reach for my Quince cashmere sweaters constantly. They're 100% Mongolian cashmere, and somehow they're just 50 bucks.
Soft, warm, and the kind of everyday luxury that doesn't feel overdone.

Speaker 2 And their denim is another favorite, great fit, easy to wear, and it holds up beautifully. And if you're looking for a holiday gift to give without the big price tag guilt, Quince is perfect for that.

Speaker 2 Those cashmere sweaters I just mentioned, they make great gifts.

Speaker 2 And their wool coats, you got to to check them out they're stylish and durable and their quality is top of the line it's amazing how many people have found quince and love it what I love is how Quince works directly with ethical factories and top artisans cutting out the middlemen so you get premium quality at half the cost of other high-end brands it's luxury without the markup which means you can give something nice this season or keep it for yourself.

Speaker 2 Give and get timeless holiday staples that last this season with Quince. Go to quince.com slash SYSK for free shipping on your order and 365-day returns.
Now available in Canada too.

Speaker 2 That's q-u-in-ce-e.com slash sysk. Free shipping and 365-day returns.
Quince.com slash SYSK.

Speaker 2 So Jackie, it does seem to me that, especially with young people, that picking up their phone is a habit. It's like they can't not do it.
Go to a doctor's office and people are in the waiting room.

Speaker 2 And I actually went to a doctor not long ago and was struck by this woman who was sitting there reading a real book. And I thought, wow, look at her.
That's so rare.

Speaker 2 But in the old days, you know, doctors used to put magazines in their waiting rooms because that's what people did to pass the time. Now it's just habit.

Speaker 2 You sit down, you whip out your phone, and you stare at it until they call your name.

Speaker 3 Yeah, I think a lot of our use is really, yeah, as you're saying, really habitual, really sort of mindless.

Speaker 3 It's not necessarily a choice we're making always to pick up our phone or to do a certain activity on our phone. It's really more that it's just automatic at this point.

Speaker 3 We've sort of gotten in the habit of using it a certain way. That's one reason why I think that,

Speaker 3 you know, one thing, one first step we can take to try to improve our relationships with our devices is to think about using it more mindfully. So less mind, lessly and more mindfully.

Speaker 3 Meaning just taking a step back and really trying to be aware of the times when we reach for our phones, you know, that sort of automatic unlocking behavior that so many of us do, and really trying to think about when we're using it and why, like what it, what's the purpose.

Speaker 2 So that's a good, probably a good place to start is to start thinking about why you're using it. But what else? Because that's a great idea, but it's a little vague.
It's like, well,

Speaker 2 be more mindful.

Speaker 2 Yeah, I don't know.

Speaker 2 But I'm sitting here and I have nothing to do, so I'm going to whip out my phone.

Speaker 2 But what's the plan? What's a way to approach this?

Speaker 3 Yeah, it's a great question. I think so the first thing, of course, is to be aware, right?

Speaker 3 To know, like, think about, you know, when we're, when we're turning to our device, what exactly we're doing on there and when that's feeling like a problem to us, right?

Speaker 3 So for many people, this is something like they're happy to use their phone for utilities, things like Google Maps to get directions somewhere, or they want to be able to make phone calls, things like that that are more utilities.

Speaker 3 Even like they want to be able to listen to a podcast like this one or to music. So maybe those are things that they want to be able to do on their phone.
They appreciate that.

Speaker 3 They don't feel like it's getting in the way. But then there are other activities they might start to recognize are sort of the culprits for things that are not making them feel as good.

Speaker 3 For many people, that's things like mindlessly scrolling social media or maybe automatically, you know, reflexively checking email or checking a news app. Those kinds of things tend to come up a lot.

Speaker 3 But there are also a lot of tools that you can use. You know, on the iPhone, there is the screen time setting.
You can go into your screen time settings.

Speaker 3 You can set time limits on certain apps, or you can block apps at different times of day using settings like downtime.

Speaker 3 Android devices also have a similar feature through their digital well-being tools.

Speaker 3 And then the other thing I would say is just outside of the sort of like technical side of things, there are things you can do just in your day-to-day habits as well to try to reduce your mindless use if that's what you're looking to do.

Speaker 3 So

Speaker 3 you can try to set phone-free times of day, whether that's meals

Speaker 3 or other times. You can try to set phone-free locations of your house.

Speaker 3 So certain places where maybe you decide you're not going to use your phone, certain rooms, or maybe on the couch or something like that.

Speaker 3 I think you can talk to your family and friends about what sort of the phone guidelines are going to be when you're spending time with each other. And that can go a long way.

Speaker 2 My guess is, as wonderful as those recommendations are,

Speaker 2 people just don't do them.

Speaker 2 It would be very hard for me to imagine to alter my

Speaker 2 use using those suggestions you just made.

Speaker 2 I'll just take care of it myself. And I imagine most people don't follow those recommendations.

Speaker 3 People do find it very hard to do this kind of thing.

Speaker 3 So in many of the studies that ask people to reduce their use

Speaker 3 of their phones or of social media, the compliance is somewhat low, meaning that it's hard to get people to do this.

Speaker 3 It's just, yeah, it's just tricky for a lot of people.

Speaker 3 But in most cases, they do find that when people stick to it, when people do it,

Speaker 3 they do end up reporting improvements in mood and well-being

Speaker 3 and other factors.

Speaker 3 So,

Speaker 3 it can certainly make a difference.

Speaker 2 Well, I've had a

Speaker 3 other thing I would note that

Speaker 3 can make a big difference in terms of well-being is trying to reduce phone use around sleep. We know that our device use can really interfere with sleep when it's keeping us awake at night.

Speaker 3 One thing that seems very simple, but can make a big difference is charging phones outside of the bedroom when you go to sleep.

Speaker 3 And there is some evidence that that can improve both the length and the quality of people's sleep.

Speaker 2 Even though you're not on it, it's just not in the room. So you can't be.
Well, what is that?

Speaker 3 Well, I think when it's in the room, the problem is that there's too much temptation for many people to grab it.

Speaker 3 So if you, you know, or maybe it's making noises in the middle of the night, that's waking you up.

Speaker 3 Or, you know, if you can't fall asleep or you wake up in the middle of the night, you reflexively go to check it, and then that keeps you awake longer.

Speaker 3 So sort of having it out of sight, out of mind can make a big difference.

Speaker 2 Well, one of the big concerns about screen time that you hear was probably the first big concern is about kids and video games and all of that.

Speaker 2 Where are we? What does the research say about all that? Is it

Speaker 2 horrible or not or what?

Speaker 3 Yeah, so with video games, I think that

Speaker 3 where the research stands right now is that unsurprisingly, it depends, right? It depends on who the kids are. Kids are affected in very different ways when they're using video games.

Speaker 3 It depends on what exactly is happening in those video games. Generally, you know, there was a big concern for a while about violence in video games.

Speaker 3 Generally, the research does not support any long-term links between playing violent video games and, you know, violent or aggressive outcomes in the long term.

Speaker 3 So some of that concern, I think, has been somewhat overblown.

Speaker 3 That said, I think there's good reason for parents to be aware of the kinds of things that their kids are being exposed to in video games.

Speaker 2 Here's something I think a lot of people wonder about, because for decades, people have gone to bed, watched TV, and then gone to sleep.

Speaker 2 I haven't heard a whole lot about that being a problem, but there's a lot of caution about looking at a screen like a phone or a tablet before bed that that screws up your sleep.

Speaker 2 What's the difference between the TV and the screen, the computer screen?

Speaker 3 Yeah, so I think in terms of the actual technology, like the and the effects, there's nothing specific about a phone or a tablet that's inherently worse than a TV, right?

Speaker 3 Like it's still a screen that's being watched and that's it. I think the, you know, practically there there are some differences.

Speaker 3 So with a tablet or a phone, obviously it's you're not having the same experience of with a TV, you turn it off

Speaker 3 and it's off. And that's sort of it.
And then you get up and you walk away.

Speaker 3 With a tablet or a phone, of course, it often comes with you. And so that makes it just a different experience in terms of the ease of putting it away, of stopping to use it.

Speaker 3 The activities that you do on a phone versus, or a tablet versus a TV also sometimes differ.

Speaker 3 You know, so you might be using more social media or other apps on a phone versus on a TV. Maybe you're watching more

Speaker 3 shows. And,

Speaker 3 you know, with a, with a TV show, it tends to have more of a definitive end point, right?

Speaker 3 Like an episode ends and that's kind of the end, versus when you're scrolling on social media, it sort of can continue on forever.

Speaker 2 Well, it's a topic that is the subject of a lot of conversation and concern, maybe especially for parents.

Speaker 2 But it's a topic I think that everyone's concerned about, how much time we're spending on screens and what we're not doing because we're spending so much time on screens.

Speaker 2 Jackie Nisi has been my guest. She's a psychologist, an assistant professor at Brown University, and she writes a popular weekly newsletter called Techno Sapiens.

Speaker 2 And if you'd like more information to that, there's a link to Techno Sapiens in the show notes for this episode. Jackie, thank you for coming on and talking about this.

Speaker 3 All right. Thank you so much, Mike.

Speaker 2 I want to tell you about a great new podcast I think you'll like. I'm loving it.
So what happens when our passions become obsessions?

Speaker 2 Well, on David Green is obsessed, one of America's most familiar voices and longtime co-host of NPR's Morning Edition, seeks out obsessives of all kinds while unpacking his own fixations.

Speaker 2 You'll hear David David talk to comedian Tig Nataro about her complex passion for plant-based food. Actor David Arquette on his love of Bozo the Clown.
Paula Poundstone on her house full of cats.

Speaker 2 Celebrity chef and author Michael Simon discusses why he just can't quit the Cleveland Browns, even though they often make him miserable, and so much more.

Speaker 2 It's pop psychology disguised as conversations with the world's most fascinating people.

Speaker 2 You can listen to David Green is obsessed wherever you get podcasts.

Speaker 2 You know, my mornings used to be a scramble, coffee, breakfast, trying to remember what supplements to take. It was a lot to juggle.

Speaker 2 And now I start every day with a single scoop of AG1 and it's made my mornings so much easier and better. In one mix, here's what I get.

Speaker 2 I get nutrients from real whole foods, plus prebiotics, probiotics, and enzymes that support my digestion and gut health. After just a few weeks, I mean, I can tell it's working.

Speaker 2 My energy feels steady all day. I don't have to think about juggling five different pills or powders.
And what I love is that AG1 isn't just another supplement.

Speaker 2 It's a daily microhabit that supports whole body health in one scoop. It's simple, it's consistent, and it fits easily into my routine.
One scoop, shake, drink, done.

Speaker 2 And I know I've done something good for myself before the day even starts. It's become a small ritual that sets the tone for the entire day.
AG1 helps me stay one scoop ahead.

Speaker 2 Head to drinkag1.com/slash something to get a free welcome kit with an AG1 flavor sampler and a bottle of vitamin D3 plus K2 when you first subscribe.

Speaker 2 That's drinkag1.com/slash something. something.

Speaker 2 How the human body works is so fascinating and so complicated from how we use food for fuel, how and why we age and can't live forever, why we sleep, why we have to sleep, yet sleep leaves us vulnerable to so many things.

Speaker 2 how our immune system keeps us alive and how evolution changes us ever so slowly. Here to explain some of these intricate bodily systems and how we can keep them working smoothly is Dr.
Dara Ennis.

Speaker 2 He is a scientist and researcher who has worked at both the University of Oxford and the University of Glasgow. He is author of a book called The Body: 10 Things You Should Know.
Hi, Dara.

Speaker 2 Welcome to Something You Should Know.

Speaker 5 Well, thanks very much for having me.

Speaker 2 So, the human body, our bodies, like every other living thing,

Speaker 2 gets older and ultimately dies.

Speaker 2 From a scientific point of view,

Speaker 2 why must that be? Do we know why that is?

Speaker 2 Because it seems like we certainly live longer than we used to, but ultimately we die.

Speaker 5 Well,

Speaker 5 why do we age is certainly a question with an answer?

Speaker 5 very deep-rooted ways that our cells and the cells of all living things work that makes them age.

Speaker 5 And one of the main things, as you know, anybody who works on aging will understand, is that our DNA, the code that makes us what we are and are the instructions for us being alive, has a lifespan in and of itself.

Speaker 5 So, you know, every high school student knows that DNA gets copied, but what they don't realize is every time it gets copied, that copy is only a tiny fraction smaller than the original.

Speaker 5 And eventually it's too small and it just goes away, you know. So

Speaker 5 that in itself

Speaker 5 is a limit. It's a ticking clock and there's nothing we can do about it.
So yeah,

Speaker 5 that's a bit of a problem for people who want to live forever, I'm afraid.

Speaker 2 But even people who get older and die from diseases that are normally associated with old age die at different ages.

Speaker 2 Some people die in their 70s or their 80s or 90s, and some people make it even longer than that.

Speaker 2 So there is a clock because ultimately nobody gets any older than whatever the maximum age is, but there is a clock.

Speaker 5 Well, it's a maximum clock.

Speaker 5 So

Speaker 5 most people don't reach that. That isn't the

Speaker 5 sort of critical factor in what ends up, you know, finishing us off, essentially. So we'll all get old and we'll all age.
But there are other factors that will damage our cells, damage our DNA.

Speaker 5 You know, exposure to sunlight makes our skin

Speaker 5 look older.

Speaker 5 Other lifestyle choices, what we eat, you know, what we do, how much exercise we take, how happy we are, how stressed we are.

Speaker 5 So it can even be a case of you can sort of think yourself young, and that is literally going to be physiologically true because stress responses age our cells.

Speaker 5 And aged cells go into a state called senescence, which is effectively where they shut down and start to die off. And that's contagious.
Other cells around it can pick it up.

Speaker 5 And the stress response is a big factor in senescence.

Speaker 5 So if you're a very stressed out person with a bad lifestyle, you're going to age a lot quicker than someone who's just happy-go-lucky and looks after themselves.

Speaker 5 So you can maximize your chances of being younger for longer, but not forever.

Speaker 2 It's never forever, is it?

Speaker 5 Unfortunately, no. No.

Speaker 2 So let's talk about blood and how blood gets circulated all throughout the body and how that all works.

Speaker 5 Well, it's driven obviously by the heart, but our blood vessels are quite elastic and they swell and shrink as the pulse rate from your heart comes.

Speaker 5 So that elastic motion helps maintain blood pressure and it's the pressure of the system that keeps it all moving.

Speaker 5 So if you have a very closely pressurized system and a pump, it means that it can reach right to the end of these tiny capillaries that are, you know, potentially a couple of meters away or a meter and a bit away from your heart.

Speaker 5 And yeah, it's just, it's a constant pressurized system with a constant flow.

Speaker 5 It's astonishingly efficient, considering it's driven by a lump of muscle about the size of our fist that doesn't make very much noise.

Speaker 5 If you ever see how much noise and energy a water pump uses to pump something that long,

Speaker 5 it's massively more efficient. Evolution beats engineering every time.

Speaker 2 So it seems like a big question, but since you tackle it, this whole idea of about getting and using energy, how food becomes energy, how we spend energy,

Speaker 2 I never really, I get, I get that it happens, but I'm not sure I have any idea how it happens.

Speaker 5 The main thing to remember is that, you know, by the laws of physics, you can't make energy. You just change its form.
That's all you do. You just mess about with the structure of it.
So

Speaker 5 energy can't be made, it can't be destroyed. So we take the energy from chemical bonds in our food and we just put it into a system that our cells can use.

Speaker 5 And it's it's really really clever and massively efficient how it does so and it's largely driven by mitochondria, which are small organelles in our cells.

Speaker 5 And the fun thing is most scientists think that they were originally independent organisms way back in our evolution when we were like single cells that were eaten essentially, but survived.

Speaker 5 And because they were so good at providing energy, they've become part of our setup.

Speaker 5 So they're an alien life form that over tens of millions of years has just come along with living animals and helps them provide their energy. So that massively makes it more efficient.

Speaker 5 And yeah, it's just, it's a series of different reactions that make food energy into the energy that our cells can use. And it's amazing.
It's astounding, to be honest.

Speaker 2 So you've mentioned a few times how, you know, this is amazing and this is really efficient. And my guess is that

Speaker 2 these systems get that way over time through evolution. But I don't know that we really understand.
I don't think evolution works the way people think it does.

Speaker 5 No, no. I do quite a lot of, you know, public events and things and people ask me science questions and I love that.
I really do because it's my real passion.

Speaker 5 But a lot of people say things like, oh, you know, in 10,000 years, we'll be have much longer fingers because we type and that's how evolution works. And it really isn't.
Evolution

Speaker 5 only works if something makes you more likely to survive and have children. Those two things have to be together.
So if it doesn't make you more likely to reproduce, then evolution throws it away.

Speaker 5 And that's it. And it's random, completely random.
But over enough time, it will eventually, you know, get us from one of those single-celled organisms to the one that can get the bus to work.

Speaker 5 But the amount of time is absolutely immense. You know, you're talking tens or possibly even over hundreds of millions of years.

Speaker 2 Well, that phrase you used about evolution throws it away. I think that's where people get confused.
That it isn't like one morning

Speaker 2 the heavens say, Well, you know, we're not going to need a tail anymore, so let's just knock that off because we don't need that.

Speaker 2 It doesn't work that way

Speaker 5 very rarely. Like, you will occasionally get a very bizarre mutation that will completely change an animal, it will change its color, or it will do something really, really weird to it.

Speaker 5 But yes, most of the time, the change is extremely gradual, and quite often it's because there's a cost to everything. So,

Speaker 5 having any part of your body or doing any action or anything producing anything costs the cells in your body something you know you have to make the proteins you have to do all of this kind of thing or there is a cost as in it makes you more likely that another animal will eat you or it makes you less likely to reproduce and if you're in a competitive environment and you

Speaker 5 as an animal change color you know you get a red stripe or something and suddenly that means the females are no longer interested in you they're not going to mate with you because you've got this red stripe that's never going to be passed on because you don't reproduce and the mutation disappears and it's just literally thrown away from the population but if it's the other way and the red stripe suddenly means all the females are interested in you then gradually over time you'll speciate so you'll become the red striped version of your of your animal and you'll produce lots and lots of children And that's it.

Speaker 5 It's purely, this is the bit that people don't understand. It's not about growing bigger teeth to fight off the predators.

Speaker 5 It's just about, are you going to survive long enough to pass those genes on and they're kind of like

Speaker 5 you know memes or viral things on the internet you know it doesn't necessarily have to be good it doesn't necessarily have to be brilliant it just has to be popular and that's it why do we sleep

Speaker 5 oh that's a weird one isn't it so by any logical sense anything that you think about an animal going to sleep is a terrible idea like it's so bad for it it makes you completely vulnerable um and And you would think that evolution of all things, this really strict, you know, filter that takes away anything that's dangerous would get rid of sleep, but it just can't.

Speaker 5 It seems to be deeply inbuilt into not just humans, but like almost all animals, like flies sleep, fish sleep, dolphins and whales sleep, even though they're like they have to, you know, breathe and all this kind of thing underwater.

Speaker 5 And it seems so inbuilt to how our nervous systems specifically work that we can't get rid of it. So the cost of getting rid of it is way too high.

Speaker 5 And if you ever meet someone who's sleep deprived, you very quickly realize why, because it just messes with us so badly.

Speaker 2 So it must do something really, really special for us to devote that much of our life to it.

Speaker 5 Oh, it absolutely does. So our brain function completely relies on sleep.

Speaker 5 So we can't get completely to the bottom of this very easily because the ethical considerations of doing sleep deprivation studies means that they very rarely go past two or three days without sleep because it's so bad for you.

Speaker 5 But in the ones that they have done or ones where people have had medical problems that kept them awake,

Speaker 5 you lose all critical function,

Speaker 5 your brain stops working completely. It's almost like you've been drinking.
You know, it's that kind of level of loss of motor control. You become emotionally problematic.

Speaker 5 You start overeating because your hormone system stopped working properly. And a really key thing as well is that your brain washes itself at nighttime.

Speaker 5 So, there's been studies where they've watched people when they're going to sleep through MRIs and

Speaker 5 CAT scanners and things. And they've seen pulses of cerebrospinal fluid going over the brain during sleep.

Speaker 5 And they really think that this downtime, this maintenance time of sleep, helps remove bad things for your brain, toxin buildup, but especially things like misfolded proteins.

Speaker 5 So misfolded proteins can lead to Parkinson's disease, to dementia, and to all sorts of other neurological problems.

Speaker 5 And without sleep, it's not able to do that because our brain is just so busy all of the time when we're awake. It's always got so much to do that it can't have maintenance.

Speaker 5 So effectively, sleep is brain maintenance mode. You need to let the janitors in to clean up.

Speaker 2 So here's, I'm so glad you tackle this in your book because

Speaker 2 How many times have we heard about how the body defends itself, that you have an immune system in it, and it, but nobody knows what that means or how it works.

Speaker 2 It's just, well, you know, I didn't get a cold and he did because my body defended itself. But

Speaker 2 how? I don't know what that means.

Speaker 5 Yeah,

Speaker 5 I think a lot of people, especially since the pandemic,

Speaker 5 got a very skewed and peripheral idea of what the immune system is and what it does because it was kind of covered on the news, but never in depth.

Speaker 5 And I've always used analogies to explain things to people and i think a great way to look at it is like a security system with guards and you've got two different systems one is your innate system which just works away on its own and it's if it finds anything foreign it'll attack it and it'll run a fever and it will provoke that kind of immune response very very quickly But then you've got your adaptive immune system, which is why we become immune to things.

Speaker 5 So this is if it sees something it recognizes from before, it will instantly find it and attack it. It's way more efficient, but you have to have been exposed to it before.

Speaker 5 And that's the whole reason why, why vaccines work is because vaccines prime that innate system.

Speaker 5 It's kind of like giving your security guards a wanted poster and going, if this guy comes along, you make sure you catch him real quick. And

Speaker 5 a lot of people don't understand how it works.

Speaker 5 There's a lot of disinformation out there because there's a lot of money to be made trying to tell people that they can not catch a common cold if they take this supplement and things, but most of it's nonsense.

Speaker 2 But is it your immune system when you cut yourself and the cut heals?

Speaker 5 It's a mixture. So, your skin is one of your best defenses, actually.
We're constantly bombarded by viruses and bacteria and funguses, and people don't realize this because they're so small.

Speaker 5 And almost all of them land on your skin and die.

Speaker 5 You know, if you're a scientist and you're doing microbiology, you have to, you know, sterilize everything and have a flow of sterile air, or you have to have a Bunsen burner to

Speaker 5 make the air above your station rise up and keep all of the spores and all of the bacteria off it because they're everywhere. They're ubiquitous.
And

Speaker 5 if you cut yourself, you open the gates, you know, so

Speaker 5 your immune system makes sure it doesn't get infected and then your body repairs it in a different way.

Speaker 5 So it's not your immune system fixing the cut, but it's making sure that nothing gets into that cut that will make it infected.

Speaker 5 And that's way more important, to be honest, because infections until relatively recently in human sort of technology, an infection like that could kill you. Because

Speaker 5 once they're in, that's when these guys, the bacteria and things cause such trouble.

Speaker 2 But going back to like catching a cold, there are some people who seem to get sicker more often than others, exposed to more or less the same things.

Speaker 2 And, you know, my wife who works in a hospital, she never gets sick.

Speaker 2 And so the assumption is, well, she doesn't get sick because she's been exposed to so many illnesses that she's built up this immunity to it. I don't know if that's true, but she never gets sick.

Speaker 5 Part of it is. So having an exposure

Speaker 5 on a constant basis boosts your immune system.

Speaker 5 Your adaptive immune system recognizes more pathogens. You're more primed to do it.

Speaker 5 But I know this is going to sound a little gross, but a very large part of the reason why healthcare professionals don't get sick is because they wash their hands properly.

Speaker 5 You know, if you're working in a healthcare environment, you're probably very carefully washing your hands for a minute or two minutes at a time, maybe 20 times a day.

Speaker 5 That's a very large reason why we get sick is because we pick up things or we shake hands with someone or we touch the door handle and then we rub our eyes or, you know, we pick something out of our teeth and it gets into our body and it escapes.

Speaker 5 But yeah, there's a little bit of a boosted immune system to it, but some of it's just practice, good practice.

Speaker 2 What's one thing about the body that you think people maybe don't understand as well as they should, or there's a lot of misinformation about it? I mean, you're out speaking to people all the time.

Speaker 2 What is it you think, if anything, there is confusion about?

Speaker 5 I think one thing that a lot of people get wrong is nutrition.

Speaker 5 There is so much commercial pressure from companies who are trying to sell what are considered healthy food and a lot of people don't understand the the genuine need for a healthy diet to keep yourself healthy.

Speaker 5 And they don't understand that a lot of the things, the supplements they're being sold, or, you know, the miracle food thing, a lot of it is nonsense or it's marginal at best.

Speaker 5 So you have people who, you know, will take some miracle, you know, powdered seaweed supplement, but then will eat nothing but fast food. And they're wondering why they're not like doing well.

Speaker 5 The overriding dietary advice since probably for a century is to eat a wide varied balanced diet that's largely based on fruit and vegetables fresh fruit and vegetables and i don't know if they did it in the us but in the uk and ireland they said five portions a day that's what they said if you have five portions of fresh fruit and veg a day that's a good start it was actually meant to be 10 But they realized if they told people they had to eat 10 different fruits and vegetables a day, they would just say, no, we're just going to give up.

Speaker 5 So five is kind of the bare minimum.

Speaker 5 And almost nobody eats five portions of fresh fruit and veg a day almost never no yeah nobody does who does yeah nobody does but that if you really genuinely want to have a healthy diet it's eat almost no processed food and almost everything is processed food which is a big problem but base it on fresh fruit and veg and cook things yourself from scratch where possible but that's not achievable in the modern world unfortunately so you know i i wish there was some fun way of of saying a healthy diet but unfortunately healthy diets are what doctors have been telling us for since like the 1920s.

Speaker 2 And lastly,

Speaker 2 what happens when we die?

Speaker 5 So, this is one I wanted to do, and I wasn't sure that you know people would want to read it, but it's actually turned out to be great, it's been very popular.

Speaker 5 Um, and I don't mean this in a spiritual way, uh, if anybody's thinking that way.

Speaker 5 This is what happens to your body when you die because a lot of people, there's big taboos about death, and you know, we like to pretend that things don't happen but our bodies go away they're gone they're gone fairly soon unless you're in very specific circumstances within a few decades there's only slight remains of bone some hair and you know some fillings or if you've got a metal implant or something that's all that's left and that process is

Speaker 5 I think fascinating, you know, what happens when you stop being a person and you suddenly become a body, literally a body. And

Speaker 5 I think a lot of people don't realize what does happen to your body. And some of the fun things, well, fun, interesting things are that not all of your cells will die at the same rate.

Speaker 5 So, you know, your brain cells die almost straight away because they need so much energy and so much oxygen. But your immune cells can last for days and days.

Speaker 5 You could have a dead body and you'd have little white blood cells four or five days later just drifting around and not realizing that the body is dead because, well, they're not sentient, so they'll never realize.

Speaker 5 But yeah, I thought thought it was, it was important for people to address this because I think we shy away from it because it's a difficult subject.

Speaker 2 Well, I know I've certainly learned a lot and understand things about how the human body functions that I didn't know before. I've been talking with Dr.
Dara Ennis.

Speaker 2 He is a scientist and researcher and author of the book, The Body. 10 Things You Should Know.
There's a link to that book at Amazon in the show notes.

Speaker 2 Dara, thanks for coming on and talking about this.

Speaker 5 Well, thanks very much for having me, Mike. It was brilliant talking to you.
I really enjoyed it.

Speaker 2 Of course, you know that talking on a cell phone when you're driving is a bad idea because it's very distracting.

Speaker 2 But it turns out that driving a car while your passengers are talking on a cell phone is also very distracting.

Speaker 2 In fact, listening to anybody talk on a cell phone is distracting because you're only hearing half of the conversation. It's called a half-alog, and it reduces your cognitive function.

Speaker 2 So, for example, if you're driving in your car and someone else in the car is talking on the phone, it's almost impossible to tune it out.

Speaker 2 So your brain is frantically trying to make sense of a conversation where you're only hearing half of it.

Speaker 2 The researchers that did the study point out that when we overhear a conversation normally, we actively try to predict how the conversation will go.

Speaker 2 And when you only hear one side of the conversation, your brain has to work harder to do what is, you know, pretty much impossible.

Speaker 2 So with less of your brain available to focus on driving, you're more at risk for an accident, which is a good reason for everyone in the car not to talk on their phones.

Speaker 2 And that is something you should know.

Speaker 2 Something you should know is produced by Jeffrey Havison, Jennifer Brennan, and our executive producer is Ken Williams. I'm Mike Carruthers.

Speaker 2 Thanks for listening today to Something Something You Should Know.

Speaker 2 The Infinite Monkey Cage returns imminently. I am Robert Ince, and I've sat next to Brian Cox, who has so much to tell you about what's on the new series.

Speaker 5 Primarily eels.

Speaker 2 And what else?

Speaker 2 It was fascinating, the eels. But we're not just doing eels, are we? We're doing a bit.

Speaker 2 Brain-computer interfaces, timekeeping, fusion, monkey business, cloud, signs of the North Pole, and eels. Did I mention the eels?

Speaker 2 Is this ever since you bought that timeshare underneath the Sagasso C?

Speaker 2 Listen on bbc.com or wherever wherever you get your podcasts.

Speaker 4 But the regency era was also an explosive time of social change, sex scandals, and maybe the worst king in British history.

Speaker 4 And on the Vulgar History podcast, we're going to be looking at the balls, the gowns, and all the scandal of the Regency era.

Speaker 4 Vulgar History is a women's history podcast, and our Regency Era series will be focusing on the most rebellious women of of this time.

Speaker 4 That includes Jane Austen herself, who is maybe more radical than you might have thought.

Speaker 4 We'll also be talking about queer icons like Anne Lister, scientists like Mary Anning and Ada Lovelace, as well as other scandalous actresses, royal mistresses, rebellious princesses, and other lesser-known figures who made history happen in England in the Regency era.

Speaker 4 Listen to Vulgar History wherever you get podcasts.