Science Vs - Sleep: All Aboard the Snooze Cruise!

Episode Date: November 8, 2019

Not sleeping enough turning you into a monster? Cutting-edge science helps us understand why. And we sort through the fads to find out, what really works to get more ZZZs. We speak with lab coordinator Pam De Young, sleep researcher Dr. Brady Riedner, and circadian scientist Prof. Russell Foster.  Check out the full transcript here: http://bit.ly/2Ns26Zt  Selected references:  Consensus on the optimal amount of sleep: http://bit.ly/2Nu33Rc  Local sleep review: http://bit.ly/33rXWGL  Drunk study: http://bit.ly/33sN1wo  Melatonin review: http://bit.ly/2WXC1EW  E-reader study: http://bit.ly/2NU67EY  Credits: This episode was produced by Rose Rimler and Lexi Krupp with help from Wendy Zukerman, along with Michelle Dang, Meryl Horn and Kaitlyn Sawrey. We’re edited by Caitlin Kenney. Fact checking by Diane Kelly. Mix and sound design by Peter Leonard. Music written by Peter Leonard, Emma Munger, Bobby Lord, and Bach. Recording assistance from Dave Drexler, Tim Peterson, Zoe Sullivan, and Martin Wiggins. Sonification of EEG data came from Dr. Gerold Baier and Dr. Thomas Hermann. A big thanks to Dr. Amandine Valomon, Prof. James Krueger, Dr. Ari Shechter, Dr. Jade Wu, Dr. Bei Bei, Dr. Connor Sheehan, Dr. Jennifer Ailshire, Dr. Agostinho Rosa, and everyone else we spoke to for this episode, especially our frustrated sleepers. Thanks for calling in! And special thanks to Chuma Ossé, the Zukerman family and Joseph Lavelle Wilson. Learn more about your ad choices. Visit podcastchoices.com/adchoices

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New episodes drop every other Thursday, starting February 1st. So, now that it's time to go to sleep, my body's tired, but my brain is not. It's 2 a.m. and I can't fall asleep because my mind is just racing. Racing, racing, racing through just random s**t. Hi, I'm Wendy Zuckerman and you're listening to Science Versus from Gimlet. This is the show that pits facts against 40 winks. On today's show, sleep. We asked people to send us a little note when they were tossing and turning at night. And by the next morning, our email was full of frustrated sleepers.

I have tried to go back to sleep. I've trimmed my toenails. I've brushed my hair. So it's 3 a.m. It used to be 2 a.m., but I decided to look on Facebook. I've drafted a text, six texts to a dude

I'd like to go on a date with. It's sort of kind of driving me nuts. I'm now watching a spider build a web on my set of shelves. It's f***ing infuriating. For some people, this was something that happened every now and then. For others, it had become the new normal. I've been having like four to five hours of sleep a night. And yeah, it sucks. It really sucks. After a while, you start to wonder like what all this interrupted sleep is doing to your brain. That's the feeling at 5.30, 5.40 in the morning. It really sucks when you're tossing and turning at night. And it turns out that a lot of us just aren't getting enough sleep.

Around a third of Americans, in fact. That's according to the CDC. A third. And the number of sleep-deprived suckers out there seems to be going up. It's a nightmare. So, do we have to take this lying down? On today's show, we are diving into the cutting-edge research on the science of sleep. It's a nightmare. So, do we have to take this lying down? On today's show, we are diving into the cutting-edge research on the science of sleep. To find out, one, what happens to our brains and our bodies when we don't get enough sleep?

Turns out, it's worse than we thought. And two, what can the best science around tell us about how to get more Zs? Does stuff like melatonin or blue light blocking glasses do anything? When it comes to sleep, there's lots of... But then there's science. Science vs Sleep is coming up just after the break. Welcome back. On today's show, sleep.

We all know it feels crap when you haven't had enough sleep. But what exactly is it doing to your body? To find out, we called up Pam DeYoung. She helps run a sleep lab at UC San Diego. Most of the time, if people ask me what I do, I just tell them I work in sales. Why? So they don't ask me questions about sleep.

So is this conversation your worst nightmare? That's Science vs. producer Rose Rimla. She's on this sleep safari with me. So we asked Pam, how many hours a night should we be getting? So most of the science has shown that you should sleep between seven and nine hours of sleep. Seven to nine hours. Yes. There are some people who seem to need less than seven hours.

Science calls them wankers. Nah. Science calls them wankers. Nah. Science calls them natural short sleepers. It's pretty uncommon, though. Maybe 3% of the population. But Pam says she hears it all the time. They all say, oh, I don't need seven hours of sleep. And you're like, OK.

But I think the average population needs between seven to nine. Less than seven things go wrong. And this is not just something your grandmother tells you. A few years ago, a group of scientists were tasked with coming up with recommendations for the optimal amount of sleep that adults need. So they combed through a few hundred studies that looked at people's health and how much they slept. And they found that those who were getting seven to nine hours of sleep on the reg

were the healthiest in the bunch. Getting less than seven hours was linked with some serious health conditions. Diabetes rates increased. Depression. Immune suppression. Weight gain. Heart disease.

So, for example, one big study found that being chronically underslept raised the risk of dying from heart disease by around 20%. Now, it can be hard to tease out the cause and effect in these studies, but we do have some clues to suggest that not getting enough sleep is leading to these diseases. We know that losing a few nights of sleep raises someone's blood pressure, increases inflammation

and can be a hit to the immune system. OK, so not sleeping enough can ravage your body. But what can it do to your mind? In the long term, studies suggest that not getting enough sleep can increase your risk of dementia. And in the short term, docs have shown in the lab that missing out on sleep makes us grumpy and dopey. If you're in an office, you can kind of see the people who don't sleep a lot.

They tend to talk more or overshare, have no filter. Studies have found that when people don't get a good night's sleep, they report feeling more pain the next day. And one study even found that people were less likely to find jokes funny. That's probably why you didn't find our amazing seven dwarfs joke funny. You know, with the doc and the grumpy and the dopey. I guess we should be more bashful about it. Ah-choo! That was sneezy.

But seriously, not getting enough sleep? It can really mess with our heads. Pam told us about this one study that measured how much slower our reaction times are when we don't sleep enough. And Rose and I were so intrigued by this study that we wanted to try it ourselves. Here's how it worked. First, we had to get only six hours of sleep, which actually didn't sound that bad. But then... Ah.

Shut up. 6.30. Everything in my body wants me to keep on sleeping. Yeah, so that's me on six hours. Not so chipper, hey. But I rolled out of bed, met Rose at work, and a few hours later it was time to test our reaction times. To do this, there's this computer program that scientists can use.

A red circle pops up on a black screen at these random times, and as soon as you see that circle you have to hit the space bar. Your task is simple, to press the space bar whenever you see the red circle. Okay, cool. Normally people at their best could hit that space bar pretty quickly but on six hours of sleep, I missed the space bar. I feel like I'm doing fine. I feel like I'm focusing. I feel like I'm going to, like, fall asleep in front of the microphone.

OK, so I did not think I did well on that. Rose was a bit more confident. But we were only at half time. In the study, researchers wanted to compare sleepy people to those who drank alcohol. And that's because science knows that drinking can make you very slow on the draw. That's one reason you're not supposed to operate heavy machinery or drive a car when you've had a few. So for us, that meant our next step was... Alright, cheers.

Cheers. For science. To... Yeah. Cheers. For science. To, yeah. Downing three beers. One down. Number two. Two to go. Let's do this.

In 30 minutes. I actually have to shotgun them. It's in the protocol. It is not. That's a lie. All right. Here we go. Chug, chug, chug, chug. Here we go. Chug, chug, chug, chug.

We finished number two. Wait. We finished number two. Two, three. Number three. Number three. Yay. And time to play the space bar game again.

Just waiting for this red dot. There it is. I feel like I should be faster. Press the space bar. I got you, space bar. F*** you. So, moment of truth. What made us worse?

Being sober but sleepy or lively but loaded? We crunched the numbers. So, moment of truth. What made us worse? Being sober but sleepy or lively but loaded? We crunched the numbers. For the big reveal. Who won? Who won? Who won? Or is that not what this is about?

Okay. So we were both worse when we were sleepy. Oh, not when we were drunk. Not when we were drunk. So we hit that space bar on the average faster when we were drunk compared to like six hours of sleep. Oh, that's funny because I was like, I was for sure like impaired in the drunk arm of this trial. Yeah, we downed those beers really fast. Yeah, we chugged. Now, in the actual study, The Real Science, which tested around 30 people, alcohol and sleep loss slowed everyone down pretty much equally. Another work

has found similar stuff, which for us was a real wake-up call. I find this quite scary when I think about all the things that I do on six hours of sleep that I would never do like with three beers in me. Like what? Like I talk to my boss. I make a science podcast. I ride my bike in traffic. I know you would never get behind the wheel after chugging three beers, but you would 100% get behind the wheel after a six hour night sleep. Huh. Given all of this, it shouldn't surprise you

that a big review paper found that being drowsy driving ups the risk of car accidents by around 30%. And it ups the risk of other accidents too. Like, an investigative team found that the Exxon Valdez oil spill was caused in part because the guy steering the ship hadn't gotten enough sleep the night before. So, we're crap when we don't sleep well. But we wanted to know why.

Like, what is happening in our sleep-deprived brains that makes us such blockheads? Well, it turns out that some recent breakthroughs in the science of sleep are starting to give us some answers. To get the goss, we spoke to Brady Radner. He's an assistant director of research at the Wisconsin Institute for Sleep and Consciousness. And are you a good sleeper? I'm a fantastic sleeper, yeah. I could probably fall asleep under my desk right now if you asked me to. But that would probably not make for good radio. So this champion sleeper told us that in the earliest days of sleep research, scientists used to think that being asleep and being awake were pretty much two different things.

So that's a very binary thing. You're either asleep or you're awake. One of the reasons they thought this was because scientists can use electrodes to measure the electrical signals in your brain when you're awake and when you're sleeping. And these signals add up to a particular pattern that looks very different in either state. Scientists have actually converted these sleep-wake patterns into sounds. And this is what they found. Here's a real person's brain while deeply asleep. And when they're awake...

Pretty cool, huh? So researchers thought for a long time that while you were awake, every part of your brain was awake, you know, making this noise. And when you were asleep, all your brain was like this. But several years ago, scientists like Brady thought, huh, you know, we're only putting a couple of electrodes on people's heads. What if we used a lot more? Then we could see what was happening in so much more of the brain. In our lab, we use 256 different locations to look at what the brain is doing. So we get a much better image. Armed with all these electrodes, Brady and

his bunch wanted to know what kind of signals they would pick up in a really sleepy person. So they brought people into their lab, they kept them up all night, measuring their brainwaves again and again and again, and these people were up. They were awake, walking, talking, reading. So you would think that Brady would have just been picking up this awake pattern.

But he was actually picking up something else as well. Pockets of their brain were asleep. So Brady's research suggests that when you're really sleepy but up and about. Your brain is awake so you're still doing stuff but a part of your brain is kind of offline. It's doing its own thing. It's kind of asleep. Other researchers have found the same thing. And now this phenomenon is called local sleep because it happens in these local areas of your brain. Maybe think of your brain as New York City. This research is showing that Staten Island can be falling asleep while Brooklyn parties on. New York City. This research is showing that Staten Island can be falling asleep while Brooklyn parties on.

Brady and other researchers we spoke to reckon that local sleep could explain why we're not at our best when we're tired. When you might be spacing out in class and not paying attention to what the teacher is talking about, even though your eyes are open and you're still hearing things in the classroom, it's possible that what's happening is that part of your brain is actually asleep. Well, you know, I feel like it kind of explains my entire life. There are probably other things going on in your brain that explain why you become the worst of the seven dwarves when

you're sleep deprived. Like there's some evidence that not getting enough sleep can affect neurotransmitters that help you stay alert. But still, this idea of local sleep, it's just so amazing. I mean, it shows that parts of your brain will fall asleep whether you like it or not. And get this, it's not just that you can be asleep while you're awake. Parts of your brain can also be awake while you're asleep. And that could explain these strange things that people sometimes do in their sleep. Things like this. I remember thinking there were cockroaches in my bed. This is Pam DeYoung, the sleep researcher who you met at the beginning of the show. And I remember taking my bed outside. So I had to get two doors open with keys, brought my bed outside, put it outside in the rain. So the rain was coming down,

went back to my room, slept on the floor and woke up in the morning, my brother being like, what are you doing? And I was like, there was cockroaches in my room. And he was like, no, there aren't. And you're sleeping on the floor. And it was like a hard, cold floor. Wait a sec. Whoa, whoa, whoa. You did that when you were asleep?

Yeah. Doing odd stuff like this in our sleep, like sleepwalking and talking or sleep eating, are known as parasomnias. And what might be happening here is that while most of the brain is sleeping, the part capable of walking or talking or moving furniture outside is awake. In one study, electrodes were scanning the brain of someone who was sleepwalking. And it was actually very sweet sleepwalking. This guy hugged and kissed the air next to him. And what the electrodes recorded was that the part of his brain responsible

for movement woke up during this period while the rest of his brain slept on. Yeah. And that's this idea that, you know, most of your brain can be totally offline, totally asleep. But the part of your brain that was responsible for executing a very specific function could still be totally awake. And so they're in this kind of mixed state. So for those of you who only got six hours of sleep last night, here's what we've learned. Sleep is really, really, really important.

It's so important that when we don't get enough of it, it increases our risk of all these nasty diseases. Plus, getting sleep is so important for you, the parts of your brain will just fall asleep, whether you like it or not. So now that we know how important sleep is, how do you get more of it? There are so many sleep hacks out there. Melatonin, blue light blocking glasses. Do any of them work? That's coming up after nap time. Welcome back. So without sleep, we get sick, we're slow, we make mistakes,

and pockets of our brain go to sleep without us. Our next question is how do we get more sleep? You can take a sleeping pill, which might knock you out, but some of them have side effects and they're not recommended in the long term. So what else is there? You look online and it seems like everyone is selling some kind of trick to get us to bed. Now there's a solution to help you fall asleep naturally. Introducing melatonin.

Care about blue light blocking glasses. The luxurious weighted blanket that helps you relax. You'll sleep better, dream better and live better. Believe science. So does any of this work? To find out, we called up this fella. Okay, jolly good. My name is Russell Foster.

I'm Professor of Circadian Neuroscience, and I am the Director of the Sleep and Circadian Neuroscience Institute here at the University of Oxford. Russell researches our circadian rhythm. So the circadian rhythm essentially tells you when's a good time to be asleep and when it's a good time to be awake. In other words, it's our internal clock. And scientists have been trying to uncover what makes this clock tick for a very long time. In fact, one of the earliest studies looking into this involved a scientist and

his assistant who, in the 1930s, moved into a cave for a month. This incredible cave complex in Kentucky. And they did this because they thought the sun might be driving our internal clock. So being without the sun in a dark cave should mess it up. So the two scientists dragged down a set of bunk beds for their stay. One interesting thing about the bunk bed is that the feet of the bunk bed sat in four buckets. And in the buckets was, what's the stuff you shove down the lavatory?

Poo? No, no, chemicals. Bleach? Bleach, yeah, that's it. So one of the unforeseen things was that the cave was full of cockroaches. And what they didn't want to be is to disturb so that the cockroaches would climb up the sides of the buckets, then fall in the bucket into the bleach and die so they wouldn't then crawl up the legs of the bunk bed and disturb them whilst they were asleep.

Actually, we think it was probably rats that they were trying to deter. But either way, it sounds pretty terrible down there. Still, they were willing to do it for science. And in 1938, this was big news. Well, if the experiment helps us to sleep better these hot nights, we vote for science. This research and later studies discovered that we do need the sun to help with our internal clock.

You see, without it, our clock doesn't run at exactly 24 hours. On average, the human body clock is around about 24 hours and 10 to 15 minutes under constant conditions. So we drift by around about 10, 15 minutes a day. So we would get up and go to bed later and later and later each day. So the sun is important to keeping our internal clock ticking on time. But there are lots of other moving parts in this clock as well. And they all work in tandem to help make us feel sleepy and wake us up.

And some of the most popular sleep products on the market right now are designed to specifically hack our clock and to help us get to sleep. And this brings us to our first sleep hack, melatonin. These days, you can find melatonin in pills, gummies and drinks. It's huge right now. In six years, the number of people using it in the US has doubled. Okay, so what is melatonin and can it actually help you sleep better? Melatonin is a hormone that the body makes naturally and we pump it out when the sun goes down. And so there's a beautiful rise in melatonin at dusk, reaches its highest point at around about four-ish in the morning in many people and then declines in anticipation of waking up in the morning. And so because melatonin

only comes out at night, it is often called the Dracula hormone. This Dracula hormone, melatonin, moves through our bloodstream. It's a signal to the body to say, OK, drink blood. No, it's a signal to say, get sleepy. And so it actually makes sense that popping melatonin in a pill could boost your natural supply and hopefully get you to sleep better. But does it work? Well, when scientists get people who have trouble sleeping or who are jet lagged to take melatonin and then report back on how they slept, people tend to say, yeah, I had a better night's sleep. But the curious thing is that when scientists objectively measure how much more people slept,

the results are kind of a letdown. Like two review papers found that people who took melatonin fell asleep just five minutes sooner compared with a placebo. It's having some mild effect, but I don't think it's a very big effect. It's certainly, if you take it, it's not going to knock you out like a sedative. So why isn't melatonin a miracle sleep drug? Well, it's probably because there's all kinds of reasons that people can't get to sleep. Anxiety, babies, Netflix. And melatonin can't help you with that stuff. Still, though, if you're an adult and melatonin is working for you,

while we don't have long-term studies, as far as we can tell, it's safe. Do we have any studies suggesting that melatonin can be toxic? I don't know of any. I think it seems to be a drug that has very few side effects whatsoever. OK, so that's a green to yellow light on melatonin. Our next stop, blue light. It's a type of light that gets emitted from our favourite bedtime gadgets

and ragging on it is all the rage right now. It is all about the blue light. Computers to our lights. We are constantly bombarded with blue light. Blue light emitted from modern electronic devices increasingly interfere with our slumber. So is this true? How bad is it to look at our screens at night?

OK, so to understand how this all might work, you have to understand that we have light-sensitive cells in our eyes. You might know about the rods and the cones from Biology 101, but... There's a third light-sensitive cell within the eye that is sending messages to the biological clock in the brain. This third kind of cell gets really turned on by blue light and it sends a message to your brain that says, it's daytime, go get them, tiger.

So the idea of not looking at your blue light-emitting phone before bed, it does make sense. But what does the research show? Well, we found a small study that had people read on an iPad for about a week. Set on their highest intensity, four hours of consecutive use on five consecutive nights. While another group read a book, you know, with pages. At the end of the week, the e-readers fell asleep later. But it was by 10 minutes.

10 minutes. Now, the studies have looked at what happens when you block this blue light, say, by wearing fancy blue light-blocking glasses before bed. And the results have been pretty mixed. So some find no effect, a few did. But ultimately, for all the hype here, the research is just pretty underwhelming, which is why Russell says... Yeah, I think we need to be a bit careful about the banging on about that. In Russell's mind, there's a much more obvious reason why looking

at your phone at night might be keeping you up. When you pick up your phone, there's all these things on it. Work emails, Twitter, the internet, that just amps us up. And it seems like we just can't help ourselves. Well, it's because we're so horribly weak as a species. We check social media or check what the latest on Brexit is. And so, you know, what you need to do is not start waking up the brain and engaging in the outside world. We went down the rabbit hole on lots of different things that are supposed to help us sleep. Some things didn't have much research behind them, like weighted blankets? Dream on. There was promising evidence that doing exercise, taking a warm bath before bed, keeping your room dark and blocking out noise like with

earplugs, that stuff can help. Waking up at the same time every morning is a good idea too. And if all that doesn't really do much, there is a special kind of therapy specifically for insomnia. That can help. But the thing is, when it comes to sleep, Russell told us that you should find out what helps you sleep better and then do it. It's working out what works best for you and then defending it. Russell told us what works for him.

Read a few pages of a book, wind down and chill. Don't discuss awkward, difficult things before you go to bed. It's very interesting. My wife always wants to discuss the family finances. And I say, nope, absolutely not. Nope, nope, nope. We're due it in the morning. Pam DeYoung, who dreamt up the cockroaches,

also has a sleep routine. She told us about it. Oh, man, I go, yeah, I have a ritual. I definitely am in bed at 10 o'clock every single night, if not earlier. And then I go into the room, I turn the fan on, I have to have the temperature. I can't give you an exact temperature gauge, but probably around 68 degrees. I have my curtains up. I have a sound machine.

What about like ocean waves? Yeah, I don't like the change. You know, like when the rain one's on and all of a sudden they have that lightning, that lightning wakes me up. Yeah, like occasionally there's like a seagull squawking. Yeah, I can't handle that. That would really get in the way. That's science versus sleep.

Good night and good luck. Okay, Rose, how many citations in this week's episode? 158. 158? Yeah, that's pretty good. And where should people go if they want to see these citations? They can click on the link in our show notes, and they can also find it on our website, which is scienceversus.show.

Thanks, Rose. Thanks, Wendy. Next week, the story of revolutionaries who fought for healthcare and won. He said to me, you know, I think you're going to be a revolutionary little girl. Wait, who said that to you? Malcolm X said that to me. This episode was produced by Rose Rimler and Lexi Krupp with help from me, Wendy Zuckerman, along with Meryl Horn, Michelle Dang and Caitlin Sorey.

We're edited by Caitlin Kenny. Fact-checking by Diane Kelly. Mix and sound design by Peter Leonard. Music written by Peter Leonard, Emma Munger, Bobby Lord and Bach. Recording assistance from Dave Drexler, Tim Peterson, Zoe Sullivan and Martin Wiggins. Sonification of EEG data came from Dr. Gerald Beyer and Dr. Thomas Herman. A huge thanks to Dr. Amandine Vallamon, Professor James Kruger, Dr. Ari Shetter, Dr. Jade Wu,

Dr. Bei Bei, Dr. Connor Sheehan, Dr. Jennifer Aylshire, Dr. Agostino Rosa, and everyone else we spoke to for this episode, especially our frustrated sleepers. Thank you so much for all the voice messages. A special thanks to Chuma Osei, the Zuckerman family, and Joseph Lavelle-Wilson. I'm Wendy Zuckerman. Back to you next time.