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

You are familiar with the advice that you shouldn’t go grocery shopping when you are hungry because you will spend more money and buy more junk. However, that’s just a piece of story. Hunger and shopping are related in other ways. This episode begins by explaining how. https://phys.org/news/2015-03-hungry-people-food.html#google_vignette The idea that spending too much time on your phone, tablet or computer is bad for you has become conventional wisdom. But is that true? What does the research say about this? It turns out it's not black and white, there are shades of gray worth understanding. Here to explain this is Jacqueline Nesi. She is a psychologist and assistant professor at Brown University who writes the popular weekly newsletter Techno Sapiens (https://technosapiens.substack.com), which provides tips to manage your screen time better. She has published over 50 peer-reviewed publications related to technology use and has appeared on CNBC, CNN, and NPR. Your body is an amazing collection of processes and systems that all work to keep you alive and moving. Most of us have no idea what goes on inside of us to make it all happen so, here to explain some of it and unravel a few mysteries of the human body and explain why we can’t live forever, how the body defends itself, why we need to sleep and so much and more is Dr. Darragh Ennis. He is a scientist and researcher who has worked at the University of Oxford and the University of Glasgow and he is author of the book The Body: 10 Things You Should Know (https://amzn.to/42ApkC5). Have you heard the word “halfalogue? It’s when you hear someone else talking on their phone but you are hearing only their side of the conversation. It can drive you crazy and it has other implications, especially if you are driving a car. Listen as I explain. https://news.cornell.edu/stories/2010/05/half-heard-phone-conversations-reduce-performance PLEASE SUPPORT OUR SPONSORS!!! FACTOR: Eat smart with Factor! Get 50% off at https://FactorMeals.com/something50off TIMELINE: Get 10% off your order of Mitopure! Go to https://Timeline.com/SOMETHING INDEED: Get a $75 sponsored job credit to get your jobs more visibility at https://Indeed.com/SOMETHING right now! SHOPIFY: Nobody does selling better than Shopify! Sign up for a $1 per-month trial period at https://Shopify.com/sysk and upgrade your selling today! Learn more about your ad choices. Visit megaphone.fm/adchoices

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Mike Carruthers?

  Gifts mean more when they have the power to give more. They can inspire more discovery, give more confidence, and unwrap more of who you are. This Black Friday, give a gift that goes beyond the box. The Dell XPS 13 Laptop. With a beautiful design and cutting-edge performance, it helps you unlock more possibilities. It's the thinnest, lightest XPS laptop yet, with touchscreen, a backlit keyboard, and long-lasting battery life to power you through your day. Built with a durable aluminum chassis, weighing just 2.2 pounds, and Intel Core processors,

• 0:42Mike Carruthers?

  it's fast, reliable, and portable enough to keep up wherever you go. Visit dell.com to explore the possibilities with XPS. While shopping, you'll also find great perks like Dell Rewards, fast, free shipping, premium support, and financing with flexible payment options. Plus, you can find great deals on monitors and accessories. That means you can score a whole new setup now for less. This Black Friday sale is one you don't want to miss. Head to dell.com/deals. That's dell.com/deals.

• 1:27Mike Carruthers?

  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.

• 1:39Speaker 01

  You know, there was a big concern for a while about violence in video games. Generally, the research does not support any long-term links between playing violent video games and violent or aggressive outcomes in the long term.

• 1:55Mike Carruthers?

  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.

• 2:06Speaker 02

  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. And they really think that this maintenance time of sleep helps remove bad things for your brain, toxin buildup.

• 2:22Mike Carruthers?

  All this today on Something You Should Know.

• 2:26Mike Carruthers?

  I imagine most of us shop for clothes online, at least some of the time. And there's always that little mystery. Is what shows up at your door actually going to look like what you think you ordered? We've all had that experience. I know my wife has ordered dresses that look beautiful in the pictures, but when they arrived, eh, not so beautiful. Cheap-looking, disappointing. And that's one of the reasons we've become such big fans of Quince. When we order from Quince, we are confident we're going to get something really nice. The quality is consistently good, and the prices are surprisingly reasonable.

• 3:06Mike Carruthers?

  I've bought their cashmere sweaters, which are gorgeous, and they start at just $60 for cashmere. My wife buys tons of stuff from Quince, and we keep coming back. Quince works directly with ethical factories and cuts out the middlemen, offering prices 50% to 80% less than similar brands. And with the holidays coming, that's a pretty compelling combination. Beautiful clothes and gifts without spending a fortune, or wondering what's really going to show up at the door. I really do recommend Quince. It's one of those companies that has earned our trust. Give the gift of quality this holiday season.

• 3:46Mike Carruthers?

  Download the Quince app for app-exclusive offers, or go to quince.com. Get free shipping on your order and 365-day returns. Now available in Canada and the UK, too. And when Quince asks where you heard about them, please let them know it was something you should know. It's the best way to support the show.

• 4:23Mike Carruthers?

  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. Hi and welcome to this episode of Something You Should Know. 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. But it turns out that shopping for anything on an empty stomach is a bad idea. 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.

• 5:06Mike Carruthers?

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

• 5:42Mike Carruthers?

  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. 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? The answers to those questions just may surprise you. And here to reveal all this is Jacqueline Nesi.

• 6:23Mike Carruthers?

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

• 6:35Mike Carruthers?

  Jackie has published over 50 peer-reviewed publications related to technology use. She's testified before US congressional and state legislative committees on issues surrounding technology and mental health. Hi Jackie, welcome to Something You Should Know.

• 6:51Speaker 01

  Hey, thank you so much for having me.

• 6:53Mike Carruthers?

  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 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 I never hear like, how exactly is it bad?

• 7:14Speaker 01

  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. 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. You know, people have very different actions to the same experience on their screens. So there's a lot that goes into it. But when it comes to thinking about the risks of screen time, I would say there's two broad categories of risk. So, one is just around the time spent and concerns that that time is getting in the

• 7:59Speaker 01

  way of other things that are important for our well-being. Whether that's, you know, spending time in person with friends or family, or spending time outside, being physically active. You know, when screen time starts to really get in the way of those things, then I think that that certainly can be a risk. The other category, I would say, is around the content we're seeing on our screens. You know, 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. And so I think that's another risk as well.

• 8:38Mike Carruthers?

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

• 8:45Speaker 01

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

• 8:50Mike Carruthers?

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

• 8:59Mike Carruthers?

  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. I find that so rude, but 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.

• 9:20Speaker 01

  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. So there's a word called technoferrence, meaning technology and interference. Typically, that's used in like parenting work, so where technology is really interfering with interactions that parents are having with their kids. And then there's another term that's kind of funny called fubbing, which is basically phone and snubbing, 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.

• 10:03Speaker 01

  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, unsurprisingly, that that 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. I think we often think that spending that time on our screens is gonna make us feel better or less bored, or whatever it might be, but actually, it does tend to have a more negative impact on our mood.

• 10:34Mike Carruthers?

  Well, I think everyone would agree with what you just said, because there are times when everybody, I mean, probably even you, likes to just scroll mindlessly through some social media something for a few minutes, 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.

• 11:04Speaker 01

  Yeah, there's an interesting study, actually, that came out last year, which I think really illustrates this, where they, it was 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. But they, half of the students, they had wait with their phones, and half of them, they had wait without their phones. And the students who didn't have their phones thought that they were going to feel worse. Thought they were going to be bored, 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. They ended up, you know, reporting better mood at the end of the study,

• 11:47Speaker 01

  because they ended up, you know, socializing with the people around them and weren't as distracted by their devices. So I think that what we think is gonna feel good is not always the thing that ends up actually making us feel good.

• 12:00Mike Carruthers?

  What did they do instead? Was it, were they just sitting there with their thoughts? Or were they, were they reading a book? Or what, what were they doing?

• 12:07Speaker 01

  No, yeah, so they, 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 they had a, 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 the other, with other students. So I think it was more about the socializing, where they ended up, you know, striking up conversations.

• 12:32Mike Carruthers?

  Well, that's the thing, is, is scrolling on your phone is a solitary activity, and you can see lots of people together, but they're all on their phones. 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.

• 12:55Speaker 01

  Yeah, you know, one of the things that we know about about screen time and 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. And part of that, I think, really comes down to the social aspects. So if we're using, you know, our phones to promote connection, 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 gonna be are gonna be good, are gonna make us feel better. But if we're using our phones in ways that are interfering with social connection, whether

• 13:37Speaker 01

  that's, you know, we're sitting in our sitting on our phones 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 gonna have a more negative impact.

• 13:53Mike Carruthers?

  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, 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, it's other people who have the problem? How do people feel about their own participation in this?

• 14:23Speaker 01

  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. 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, 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.

• 14:52Mike Carruthers?

  And yet, probably don't do much to remedy a concern that they admit they have.

• 15:00Speaker 01

  Yeah, you know, I think that part of what makes us so challenging is that, you know, the screens that we're using right now, phones in particular, smartphones, 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 know that there are features of our devices like notifications, which sort of ping and remind us to come back to them. Or if we're on social 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. These kinds of things really make it so that we are inclined to use our devices more.

• 15:44Mike Carruthers?

  I want to ask you if you think that we're at the point now where phones, screens are becoming, I don't know, a crutch or a habit, maybe. I'm speaking with Jackie Niesi. She is a psychologist and assistant professor at Brown University, and she writes the weekly newsletter, Techno Sapiens. This episode is sponsored by Vinted. You know, I remember interviewing an organizing expert who offered this really clever trick for figuring out which clothes you should get rid of. You go to your closet and you look at the clothes hanging there. And chances are, the ones toward the middle are the clothes you wear most often.

• 16:25Mike Carruthers?

  But the clothes pushed way over to the left or the right, some of those you probably haven't worn in years, and yet there they hang, taking up space. But here's the thing, you could turn those clothes into money. That's where Vinted comes in. Vinted is a secondhand marketplace app where you can sell clothes you no longer wear and make some extra money. Listing on Vinted is so quick and simple, and when something sells, Vinted creates a prepaid shipping label for you. And here's what I really like, Vinted charges no seller fees, so whatever you earn from selling your clothes, you keep. Think about that.

• 17:06Mike Carruthers?

  Clothes that you aren't wearing, taking up space, could be putting money back in your pocket. So here's my suggestion. Take five minutes, go look at the far ends of your closet and see what's hanging there. You might be surprised. Download the Vinted app for free and start listing with no seller fees. You keep every dollar you earn. That's Vinted, V-I-N-T-E-D.

• 17:32Mike Carruthers?

  If you listen to something you should know regularly, you know we talk about sleep quite a bit here. And one of the things I've learned from those conversations is just how important a good night's sleep is. And I've always been someone who loves his sleep. So I was intrigued when I heard about Beam Dream. It's a delicious nighttime drink formulated to help you fall asleep faster, stay asleep, and wake up refreshed. It contains ingredients like reishi, magnesium, L-theanine, epigenin, and melatonin. They have lots of great flavors. I tried the cinnamon cocoa flavor, and I love the idea of having something warm and delicious as part of winding

• 18:15Mike Carruthers?

  down at night. And it's less than 20 calories per serving. Dream has improved more than 30 million nights of sleep, and they back it up with a 30-day money-back guarantee. If you don't sleep better, you get your money back. And right now, there's a terrific offer. Go to shopbeam.com/sysk. Use code S Y S K and get 50% off during Beam's cyber sale. Only available while flavors are in stock. With this incredible discount, that means you'll pay just 83 cents per night for the best sleep of your life. So seriously, think about it. I mean, how much would you pay for a truly great night of sleep? Beam is just 83 cents

• 19:00Mike Carruthers?

  per night. So go to shopbeam.com/sysk now. That's shopbeam.com/sysk.

• 19:10Mike Carruthers?

  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. 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.

• 19:34Speaker 01

  That's so rare.

• 19:35Mike Carruthers?

  And but but in the old days, you know, the doctors used to put magazines in their waiting rooms because that's what people did to pass the time. Now it's just habit. You sit down, you whip out your phone and you stare at it until they call your name.

• 19:52Speaker 01

  Yeah, I think a lot of our use is really, yeah, as you're saying, really habitual, really sort of mindless. 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. We've sort of gotten in the habit of using it a certain way. That's one reason why I think that, 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, more mindfully. Meaning just taking a step back and really trying to be

• 20:33Speaker 01

  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 about when we're using it and why, like what it what's the purpose?

• 20:46Mike Carruthers?

  So that's a good, probably a good place to start is to start thinking about why you're using it. But but what else? Because that's

• 20:54Speaker 01

  Yeah.

• 20:54Mike Carruthers?

  a great idea, but it's a little vague. It's like, well,

• 20:57Speaker 01

  Yeah.

• 20:57Mike Carruthers?

  be more mindful. Yeah, I know. I know. But I'm sitting here and I have nothing to do, so I'm going to whip out my phone. And but but like, what's the plan? What's what's a way to approach this?

• 21:09Speaker 01

  Yeah, it's a great question. I think so. The first thing, of course, is to be aware, right? 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? 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. 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, they want to be able to do on their phone. They appreciate that. 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. For

• 21:54Speaker 01

  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. 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. You can, you can set time limits on certain apps, or you can block apps at different times of day, using settings like downtime. Android devices also have a similar feature through their well, digital wellbeing tools. 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

• 22:39Speaker 01

  do just in your day-to-day habits as well, to try to, you know, reduce your mindless use, if that's what you're looking to do. So you can try to set, you know, phone-free, like, times of day, whether that's meals, or other times. You can try to set phone-free locations of your house. 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. I think you can, you know, talk to your family and friends about what sort of the, the phone guidelines are going to be when you're spending time with each other. And that can, can go a long way.

• 23:16Mike Carruthers?

  My guess is, as wonderful as those recommendations are, people just don't do them. They, it would be very hard for me to imagine. To alter my use using those suggestions you just made, I'll just take care of it myself. And I imagine most people don't follow those recommendations.

• 23:40Speaker 01

  People do find it very hard to do this kind of thing. So in many of the studies that ask people to reduce their use of their phones or of social media, the compliance is somewhat low, meaning that it's hard to get people to do this. It's just, yeah, it's just tricky for a lot of people. But in most cases, they do find that when people stick to it, when people do it, they do end up reporting improvements in mood and well-being and other factors. So it can, it can certainly make a difference.

• 24:17Mike Carruthers?

  Well, I've had that.

• 24:17Speaker 01

  The other, the other thing I would note that, that 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, you know, keeping us awake at night. You know, one thing that seems very simple but can make a big difference is charging phones outside of the bedroom when you go to sleep. And there is some evidence that that can improve both the length and the quality of people's sleep.

• 24:48Mike Carruthers?

  Even though you're not on it, it's just not in the room, so you can't be, well, what is that?

• 24:54Speaker 01

  Right. Well, I think the, when it's in the room, the problem is that there's too much temptation for many people to grab it. So if you, you know, or maybe it's making noises in the middle of the night that's waking you up. 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. So sort of having it out of sight, out of mind can, can make a big difference.

• 25:17Mike Carruthers?

  Well, one of the big concerns about screen time that you hear was probably the first big concern is about kids and, and video games and, and all of that. Where are we? What does the research say about all that? Is it, is it horrible or not? Or what?

• 25:36Speaker 01

  Yeah, so with video games, I think that 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. 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. 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. So some of that concern, I think, has been somewhat overblown.

• 26:19Speaker 01

  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.

• 26:27Mike Carruthers?

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

• 26:54Speaker 01

  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? Like, it's still a screen that's being watched, and that's it. I think the, you know, practically, there are some differences. 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, and it's off. And that's sort of it. And then you get up and you walk away. 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

• 27:39Speaker 01

  stopping to use it. The activities that you do on a phone versus, or a tablet...

• 27:46Speaker 01

  Versus a TV, also sometimes differ, 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, more shows. And, you know, with a, with a TV show, it tends to have more of a definitive endpoint, right, 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.

• 28:10Mike Carruthers?

  Well, it's a topic that is the subject of a lot of conversation and concern, maybe especially for parents, 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. Jackie Neese has been my guest, she's a psychologist, an assistant professor at Brown University, and she writes a popular weekly newsletter called Technosapiens. And if you'd like more information to that, there's a link to Technosapiens in the show notes for this episode. Jackie, thank you for coming on and talking about this.

• 28:49Speaker 01

  All right, thank you so much, Mike.

• 28:51Mike Carruthers?

  So here's the problem with drinking water. You can't tell if it's clean just by looking at it. A glass of water can look perfectly clear and still contain things you definitely don't want to drink. In fact, three out of four US homes have toxic chemicals in their tap water. An ordinary refrigerator and pitcher filters, they do little to remove many of these contaminants, which is why Aqua True is different. Aqua True is a countertop water purifier with a patented four-stage reverse osmosis system. It's tested and certified to remove 84 contaminants, including chlorine, lead, forever chemicals,

• 29:36Mike Carruthers?

  and those microplastics. And there's no plumbing, no installation, you just put it on the counter and you get pure, great tasting water, you can actually feel good about drinking. Aqua True was even named best countertop water filter by Good Housekeeping. Look, if you're gonna drink water every single day, and you probably should, well, why guess what's in it? Go to aquatrue.com now for 20% off your purifier using promo code S Y S K. Aqua True even comes with a 30-day best tasting water guarantee. That's aquatrue.com, A Q U A T R U dot com, promo code S Y S K.

• 30:20Mike Carruthers?

  Hiring the wrong person is expensive, but it's also exhausting. Because now, you haven't solved your problem, you've created a new one. You've spent time interviewing and training somebody, but it's the wrong person, and it's just not working. So when you're hiring, you don't just need a person, you need the right person. And that is a job for Indeed Sponsored Jobs. Sponsored Jobs helps you reach candidates with the skills and experience and other qualifications you're looking for, and boosts your job in search results, so the right people are more likely to see it.

• 31:02Mike Carruthers?

  In fact, Sponsored Jobs posted directly on Indeed are 95% more likely to report a hire than non-sponsored jobs. So give yourself a better shot at finding the right person. Spend less time searching and more time actually interviewing candidates who check all your boxes. Less stress, less time, more results. When you need the right person to cut through the chaos, this is a job for Indeed Sponsored Jobs. And listeners of this show will get a $75 sponsored job credit to help get your job the premium status it deserves at indeed.com/podcast.

• 31:43Mike Carruthers?

  Just go to indeed.com/podcast right now and support our show by saying you heard about Indeed on this podcast. Indeed.com/podcast. Terms and conditions apply. Need the right hire fast? Then this is a job for Indeed Sponsored Jobs.

• 32:06Mike Carruthers?

  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. 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. He is a scientist and researcher who has worked at both the University of Oxford and the University of Glasgow.

• 32:48Mike Carruthers?

  He is author of a book called "The Body: Ten Things You Should Know." Hi, Dara, welcome to Something You Should Know.

• 32:54Speaker 02

  Thanks very much for having me.

• 32:56Mike Carruthers?

  So, the human body, our bodies, like every other living thing, gets older and ultimately dies. From a scientific point of view, why must that be? Do we know why that is? Because it seems like we certainly live longer than we used to, but ultimately, we die.

• 33:18Speaker 02

  Well, the why do we age is certainly a question with an answer. You know, there's very deep rooted ways that our cells and the cells of all living things work that makes them age. 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. 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. And eventually, it's too small and it just goes away, you know?

• 33:59Speaker 02

  So, that in itself is a limit, it's a ticking clock, and there's nothing we can do about it. So, yeah, that's a bit of a problem for people who want to live forever, I'm afraid.

• 34:10Mike Carruthers?

  But even people who get older and die from diseases that are normally associated with old age, die at different ages. Some people die in their 70s, or their 80s, or 90s, and some people make it even longer than that. So, there is a clock, because ultimately, nobody gets any older than whatever the maximum age is, but there is a clock.

• 34:34Speaker 02

  Well, it's a maximum clock. So the most people don't reach that. That isn't the the 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, you know, exposure to sunlight makes our skin look older, other lifestyle choices, what we eat, you know, what we do, how much exercise we take, how happy we are, how stressed we are. 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 ourselves.

• 35:17Speaker 02

  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. And the stress response is a big factor in senescence. 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. So you can maximize your chances of being younger for longer, but not forever.

• 35:42Mike Carruthers?

  It's never forever, is it?

• 35:44Speaker 02

  Unfortunately, no.

• 35:45Mike Carruthers?

  No. So let's talk about blood and how blood gets circulated all throughout the body and how that all works.

• 35:55Speaker 02

  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. So there that elastic motion helps maintain blood pressure. And it's it's the pressure of the system that keeps it all moving. 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. And yeah, it's just, it's a constant pressurized system with a constant flow. It's astonishingly efficient, considering it's driven by, you know, a lump of muscle about the size of our fist that doesn't make very much noise.

• 36:36Speaker 02

  If you ever see how much noise and energy a water pump uses that to pump something that long, it's it's massively more efficient. Evolution beats engineering every time.

• 36:48Mike Carruthers?

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

• 37:06Speaker 02

  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 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. 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. 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. And because they were so good at providing energy, they've become part

• 37:51Speaker 02

  of our, our setup. 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. And yeah, it's, 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.

• 38:13Mike Carruthers?

  So you've mentioned a few times how, you know, this is amazing and this is really efficient. And, and my guess is that, that the systems get that way over time through evolution. But I don't, I don't know that we really understand, I don't think evolution works the way people think it does.

• 38:30Speaker 02

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

• 39:15Speaker 02

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

• 39:22Mike Carruthers?

  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 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. It doesn't work that way.

• 39:41Speaker 02

  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. But yes, most of the time the change is extremely gradual. And quite often it's because there's a cost to everything. So the 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, as an animal, change color, you know,

• 40:25Speaker 02

  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. It's purely, this is the bit that people don't understand. It's, it's not about growing bigger teeth to fight off the predators. It's just about, are you going to survive long enough to pass those genes on? And they're kind of like, you know, memes or viral things on the internet, you know, it doesn't necessarily have to be good.

• 41:09Speaker 02

  It doesn't necessarily have to be brilliant. It just has to be popular and that's it.

• 41:14Mike Carruthers?

  Why do we sleep?

• 41:16Speaker 02

  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. And you would think that evolution of all things, this really strict, you know, filter that takes away anything that's dangerous will get rid of sleep. But it just can't. 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. And it seems so inbuilt to how our nervous system specifically work that we can't get rid of it.

• 42:01Speaker 02

  So the cost of getting rid of it is way too high. And if you ever meet someone who's sleep deprived, you very quickly realise why, because it just messes with us so badly.

• 42:12Mike Carruthers?

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

• 42:19Speaker 02

  Oh, it absolutely does. So our brain function completely relies on sleep. 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. But in the ones that they have done are ones where people have had medical problems that kept them awake. You, you lose all critical function. And your brain stops working completely. It's almost like you've been drinking, you know, it's, it's that kind of level of, of loss of motor control. You become emotionally problematic. You start overeating because your hormone system stopped working properly. And a really key thing as well is that your brain washes itself at night time.

• 43:05Speaker 02

  So there's been studies where they've watched people when they're going to sleep through MRIs and, and CAT scanners and things. And they've seen pulses of cerebrospinal fluid going over the brain during sleep. And they really think that this downtime, this maintenance time of sleep helps remove, you know, bad things for your brain, toxin buildup, but especially things like misfolded proteins. So misfolded proteins can lead to Parkinson's disease, to dementia and to all sorts of other neurological problems. 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. So effectively, sleep is brain maintenance mode. You need to let the janitors in to clean up.

• 43:50Mike Carruthers?

  So here's, I'm so glad you tackle this in your book because how many times have we heard about how the body defends itself? That you have an immune system in it and it, but, but I, nobody knows what that means or how it works. It's just, well, you know, I didn't get a cold and he did because my body defended itself. But how? I don't know what that means.

• 44:14Speaker 02

  Yeah, I, I think a lot of people, especially since the pandemic, 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. 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. So this is, if it sees something

• 44:57Speaker 02

  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. And that's the whole reason why, why vaccines work is because vaccines prime that innate system. It's kind of like giving your security guards a wanted post. They're going, if this guy comes along, you make sure you catch him real quick. And a lot of people don't understand how it works. 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.

• 45:31Mike Carruthers?

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

• 45:36Speaker 02

  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. And almost all of them land on your skin and die. You know, if you're a scientist and you're doing microbiology, you have to sterilize everything and have a flow of sterile air, or you have to have a Bunsen burner to 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 if you cut yourself, you open the gates, you know. So your immune system makes sure it doesn't get infected. And then your body repairs it in a different

• 46:21Speaker 02

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

• 46:43Mike Carruthers?

  But going back to catching a cold, there are some people who seem to get sicker more often than others, exposed to more or less the same things. And, you know, my wife who works in a hospital, she never gets sick. 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.

• 47:10Speaker 02

  Part of it is. So having an exposure on a constant basis boosts your immune system. Your adaptive immune system recognizes more pathogens. You're more primed to do it. 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. 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. 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. But yeah,

• 47:55Speaker 02

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

• 47:59Mike Carruthers?

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

• 48:14Speaker 02

  I think one thing that a lot of people get wrong is nutrition. 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 genuine need for a healthy diet to keep yourself healthy. 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. 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

• 48:55Speaker 02

  why they're not like doing well. The overriding dietary advice since probably first 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. So five is kind of the bare minimum. And almost nobody eats five portions of fresh fruit and veg a day.

• 49:35Mike Carruthers?

  Almost never. No, yeah, nobody does. Who does?

• 49:38Speaker 02

  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 wish there was some fun way of saying a healthy diet, but unfortunately, healthy diets are what doctors have been telling us for since like the 1920s.

• 50:07Mike Carruthers?

  And lastly, what happens when we die?

• 50:11Speaker 02

  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. And I don't mean this in a spiritual way, if anybody's thinking that way. 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, I think, fascinating, you know,

• 50:54Speaker 02

  what happens when you stop being a person and you suddenly become a body, literally a body. And 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. 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. 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. But yeah, I thought it was, it was important for people to, to address this because I think we shy away from it because it's a difficult subject.

• 51:39Mike Carruthers?

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

• 52:00Speaker 02

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

• 52:07Mike Carruthers?

  Of course, you know that talking on a cellphone when you're driving is a bad idea because it's very distracting. But it turns out that driving a car while your passengers are talking on a cellphone is also very distracting. In fact, listening to anybody talk on a cellphone is distracting because you're only hearing half of the conversation. It's called a half-a-log, and it reduces your cognitive function. 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. So your brain is frantically trying to make sense of a conversation where you're only hearing half of it.

• 52:51Mike Carruthers?

  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. 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. 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. And that is something you should know. Something You Should Know is produced by Jeffrey Havison, Jennifer Brennan, and our executive producer is Ken Williams. I'm Micah Rutherford. Thanks for listening today to Something You Should Know.

• 53:34Speaker 03

  Progressive's Accident Response can contact emergency services if you're in a major accident. The only thing worse than someone you love being in an accident is not being able to help them. So Progressive is here to help when you can't. So get peace of mind knowing your loved ones are protected with Progressive's Accident Response. Learn more at progressive.com. Progressive Casualty Insurance Company and Affiliates. Limited availability in California. Driver is responsible for emergency and towing charges not covered by the policy. Coverage subject to policy terms and conditions.

• 54:03Speaker 04

  As wish lists grow, you know where to go. Head to Ulta Beauty. We have gifts they'll love from brands like Tato One and Rare Beauty by Selena Gomez. Shop beauty faves to give or keep from Shark Beauty, Sol de Janeiro, and more. Not sure what they want? You can't go wrong with Balmain, Clinique, or Redken. And don't forget to put yourself on the list. Book a salon moment or add a little more sparkle to your season. Shop holiday in-store or at Ulta.com. Ulta Beauty.