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Matt Walker: Sleeping Enough to Be Truly Awake



Nov 12, 2016

Guest: Matt Walker, Ph.D.
Host: Amit Dungarani
Moderator: Aryae Coopersmith


Aryae: Matt Walker, Ph.D. is professor of Neuroscience and Psychology at the University of California (UC) Berkeley and the director of the Sleep and Neuroimaging Laboratory. Research in the laboratory focuses on the cognitive aspects of the sleeping brain by using a multi-modal imaging approach which includes MRI, neurophysiological, and psycho-physical techniques.

Calling the global sleep loss epidemic “the greatest public health challenge we now face in the 21st century,” Matt examines the impact of sleep loss on the human brain function in clinical and healthy populations. Through his work at UC Berkeley, he has been at the forefront of sleep research. He has linked sleep deprivation to multiple disorders—psychiatric, obesity, risky behavior, post-traumatic stress disorder (PTSD), learning, and memory loss in old age. He has found a link between poor sleep and the build up of a protein related to Alzheimer's disease: a major breakthrough in our understanding of the disease that shows just how critical a good [night’s] sleep is to all of us.

Matt earned his Ph.D. in Neurophysiology from the Medical Research Council in London. Subsequently, he became Professor of Psychology at Harvard Medical School. He is the recipient of funding awards from the National Science Foundation and the National Institutes of Health. He has been featured on CBS’ 60 Minutes and on the National Geographic documentary Sleepless in America. He is a fellow of the National Academy of Sciences. To date he has published more than 80 research studies describing the critical importance of sleep for learning, memory, creativity, emotional regulation, and cardiovascular health.



[Matt] has just returned yesterday from the United Kingdom after having given talks throughout Europe. Matt, we are delighted [to have you] and thank you for being with us today.

Matt: Well, thank you very much for having me; I’m delighted to be sharing this time and this space with the Awakin audience. Thank you.

Aryae: So, let’s start at the beginning. Sleep is one of the most familiar things to all of us and yet what do we know about it? Can you start off with talking a little bit about what actually is sleep and the different issues and ways we deal with sleeping.

Matt: Sleep used to be this remarkable enigma in science. Until very recently [there was no consensus] as to why we slept, which is remarkable if you think that we've known the functions of the three of the main biological drives (to eat, to drink, and to reproduce) for many years. But this fourth biological drive which is common across every living species--the drive to sleep--has eluded scientific judgment.

And the best that we used to have in terms of an explanation was that the reason that we sleep was to cure sleepiness—which, if you think about it, is a profoundly unhelpful answer. It's like saying the reason that we need to eat is to cure hunger. And that tells you nothing about the nutritional benefits that food actually provides.

But now over the past 10 years, through an explosion of the most wonderful science, we understand that there is no single process within your brain, and there is no single physiological process within the body, that is not powerfully enhanced when you get sleep or demonstrably impaired when you don’t get enough.

So now we've been forced to up-end the question in a way. Rather than asking “What is the function of sleep?”, we've been forced to ask, “Is there anything that does not benefit from sleep?” And the answer is no. Everything is tied to sleep in one way or another. So I hope we can explore those different functions and perhaps shatter some myths around sleep and insufficient sleep.
But in responding to your question, “What is sleep?”--that is such a critical question. I think many of us think that we think we lose consciousness, and our brain is dormant and our body gets a little bit of rest, and gets some recharging, and then we wake up. So what is the harm if we short change our sleep by going to bed late or waking up a little too early with an alarm clock?

Sleep is not a dormant state. It is an incredibly active state in the brain and in the body. There are some parts of your brain that are up to 30% more active in some stages of sleep relative to when you are awake.

There are two principal stages of sleep that we cycle through when we are asleep that many people might have learned about. One of them is non rapid eye movement sleep or non-REM sleep. The other is rapid eye movement sleep or REM sleep, which is commonly associated with dreaming.

And it turns out that you ebb and flow through a cycle of REM to non-REM sleep every 90 minutes. And you will replay that 90 minutes cycle every 90 minutes throughout the night. It is an incredible cerebral war that is won and lost between these two stages of sleep.

What is interesting is that although that 90-minute cycle of non-REM to REM is stable across the night, the ratio balance of REM to non-REM sleep changes as you move across the night. So in the first half of the night the majority of those 90-minute cycles is comprised of that deep non-REM sleep--that sort of classic restorative sleep that we think about. With very little REM sleep, very little dreaming happens in the first half of the night.

As you push through the second half of the night, now that seesaw balance actually changes. And instead much more of those 90= minute cycles are composed of rapid eye movement sleep and a lot less deep non-REM sleep. And all of these stages of sleep are important.

And the reason I try to emphasize this is not for the dry academic information. It has a big impact on your sleep depending on how you sleep. And what I mean by that is, if you go to bed a little bit too late--perhaps an hour or two hours later than you normally would--and you asked, “How much sleep have I lost compared to a normal eight hours?” You might think I've lost 25% of my sleep since I've gone to sleep 2 hours later than normal. I am going to wake up at the same time, so I only got six hours of sleep rather than eight. But that is not true actually. You didn't just lose 25% of your sleep. You have probably lost up to 60 to 70% of your deep sleep.

And it works the same way on the backend, too. Let's say you are a teenager and you've gone to bed at the normal time, but you have to wake up for your early school bus that next morning because you have got athletic training. You have to wake up maybe an hour and a half or two hours earlier than you would otherwise. How much sleep have you lost? Maybe 20 or 30%? Well true. You've lost that much total sleep. But you have actually lost maybe 80%-90% percent of your REM sleep. So we have to be so careful. We can't afford to burn the candle at either one of those ends based on how sleep plays out throughout the night in terms of this canonical structure. I hope that gives people an idea of the framing and the types of sleep and this beautiful ballet of physiology when you watch it [sleep]. I’m so lucky to watch it at my lab each night.

Aryae: The complexity of this is very interesting. I know that my own habits tend to be I've lost an hour or two of sleep tonight, so I'll sleep an hour or two extra tomorrow night. My understanding of what you're saying is that this will not catch me up.

Matt: No, this is one of the myths that is so critical for people to recognize and embrace. We've found no evidence that you get back all of the sleep that you lose. What I mean is that sleep is not like the bank. You cannot accumulate at debt and hope to pay it off at a later point in time.

Now this isn't to suggest that if I deprived you of sleep tonight, and then asked you how much sleep are you going to get the next night when I give you a chance to recover, you are going to sleep longer on that recovery night. However that’s not what you do. Let's say you normally sleep eight hours, and I deprive you of sleep one night, and so the next night we would expect that if sleep did work like the bank, that you would sleep your normal eight hours and then you would recruit the entire debt the entire eight hours that I deprived you of the night before. So you would sleep 16 hours. But you don't. Not even close. You may sleep perhaps 10 hours. Maybe 11 hours. And even if I let you keep going, even if I let you sleep as much as you want after deprivation, you never get back all that you lost. So there is no safety net in place. And that is not the case for other aspects of your body. Let's take calories for example. Your body does have a credit system for calories. They are called fat cells. And we have developed this system of fast or feast or famine and plenty. And our bodies have learned that there will be times where there is lots of food around so you can store it and hold onto those calories because there may be famine ahead. There is nothing like that for sleep.

And you may ask why? And the answer is this: human beings are the only species that deprives themselves of sleep. No other species that we see will do this without biological gain. And what that means is that evolution has never faced the challenge of insufficient sleep since the dawn of time. As a consequence, Mother Nature has never had to solve this problem of insufficient sleep, so there is no safety net.

Aryae: Interesting. I want to ask you another general question about sleep. I noticed that when I was younger and I missed sleep, I could normally bounce back and have my same energy on the following day and the day following that. But as I've gotten older, it doesn't seem to work like that; losing sleep seems to carry forward many days. And I'm wondering what's the difference between sleep in a younger person and sleep in an older person?

Matt: There are two interesting questions there. When is and how is sleep different across the lifespan? And the second is how do older and younger adults deal with insufficient sleep?

In terms of sleep across the lifespan, there are just dramatic changes. Some of the most dramatic changes happen in the first 18 to 24 months of life. Your sleep structure changes. You start to stabilize. You start to have longer regular bouts of sleep. And then you start to have different types of sleep. An infant when it sleeps seems to have predominately rapid eye movement sleep. And very little deep sleep which is very interesting. And that seems to be common across almost every single mammal that we have studied. And then non-REM sleep starts to develop later in life. And we're not entirely sure why. Why is it that REM sleep dominates early in life? There's a theory that it's actually a critical igniter of brain development. That REM sleep or dream sleep sparks all of these neural pathways and makes them flourish. It is like an internet service provider in the brain that populates the brain with all of these high-speed broadband connections.

Then there's another dramatic change that happens in our sleep. And it happens right around adolescence. What we see is that sleep time preference changes. What I mean by that is that when you are a younger child, you want to stay up late, but it is nearly impossible. You fall asleep early and much to the chagrin of your parents, you wake up early. Once you hit adolescence a dramatic shift happens in what we call the 24-hour biological clock rhythm, or your circadian rhythm. What that means is that you now want to go to bed later and wake up later. And there is nothing you can do about it. No amount of parental ranting and raving is going to make you fall asleep as a teenager at 9 o'clock because you have to wake up at 6 a.m. the next morning to catch the bus. And that is one of the most profound tragedies of society in industrialized nations right now--the brute forcing of adolescent teen sleep against its biological natural tendency. And this is doing our youth a terrible disservice.

Then we gain or maintain this regular sleep pattern in our mid-to-late twenties. But then sadly comes the great sleep depression. And it happens early, somewhere between your thirties and your forties. If you were to come into my laboratory, we could measure the decline of your deep sleep quality. So even by the fourth or fifth decade of life, sleep starts to deteriorate.

By your seventies or your eighties, it’s actually really difficult for us to pick up really deep sleep. You've actually lost most of that deep sleep. We've actually done work in the last five years to explore why and what the reasons are. And it is even more profound in diseases like dementia, particularly in Alzheimer's disease. Very recently we've discovered that these two things that we very commonly associated with aging--poor memory or poor cognitive function and poor sleep--they aren't simply coincidental. They are, in fact,  significantly interrelated. And the destruction of deep sleep in later life is perhaps one of the most under-appreciated factors that is contributing to what we call cognitive decline, and now it seems Alzheimer's disease as well.

So it is very difficult with aging. There is now good evidence that older adults do not simply need less sleep. That is another myth that I would like to dismantle. A lot of people think that as we get older maybe we're not as active or maybe we're not learning as much or maybe our brain and our body don't need sleep as much. That is just not true. All signs point to the fact that sleep need remains just as high, but sleep-generating capacity is eroded and declines.

In other words, the older adult brain cannot produce the sleep that it nevertheless still needs. We are now desperately trying to find innovative new ways to restore sleep in the elderly. It is one of the moonshot goals in my laboratory. Can we give back and boost and amplify deep sleep in older adults? And in doing so can we salvage aspects of learning and memory function? And can we start to fight back against disorders like Alzheimer's disease? That is the very real hope now.

Aryae: All right. Well, all of us older adults will be rooting for you Matt. But I’d like to shift direction a little bit. You've mentioned your sleep and neuroimaging laboratory, and you've also mentioned the explosion of science. Would you tell us a little bit about the work that you're currently doing in the lab? And what is this explosion of science that you're talking about? And how is that helping you discover some of these new things about sleep?

Matt: So the research that I do in my lab has many different programs. Some of them as you mention are clinical. I'm not an M.D. by the way, and I don't pretend to be one or play one in the public forum. I am a Ph.D. But we do work with clinical populations and psychological populations and patients with Alzheimer's and dementia. But we also do a lot of basic science research. We're still trying to uncover all of these nutritional benefits that sleep provides to the brain and to the body. And there's still a lot more to discover.

But the explosion of research and understanding about sleep has been driven by technology. We have all of these new methods of brain science to actually explore sleep in ways that we actually never could before. We can actually measure patterns of brain wave activity during sleep. And we can also peer deep into the brain with things like MRI scanners as people are sleeping. And we can look to see which parts of the brain are switching on and switching off. And we can also sort of decompose these brain wave patterns, and really understand their individual parts, like a prism where you’re beaming white light and you can break it apart into its component shades and hues. We are able to do that now with remarkable technologies. By doing that we are able to speak in the currency of the brain which is in oscillations and brain waves and patterns of brain activity and networks of brain activity. And we are able to explore the body and find out more detail than we ever could before. We can look at genetics now through genetic screening—we can do blood draws; we can do measurements of heart rate and cardiac function, and we can start to unite all these things together. We can get a holistic view of the human while they sleep. And then we can see how that predicts the same set of measurements while they are awake. And then pattern match those two and then understand so much more about sleep. So it's been this revolution of new science and technology that allows us to understand these living organisms and live homosapiens included. And it is that which has given us traction that perhaps we did not have in the nineteen sixties or seventies regarding sleep.

Aryae: That is fascinating; it must just be amazing to see all these different things going on in the body and in the brain and make the correlations. I'm curious: is there a particular focus of your research currently or this year--a particular direction that you are going in?

Matt: We have several different areas at work that we are doing. For example, one of them is working with aging and Alzheimer's disease. Right now, based on work that is really coming out of my lab and some other labs around the world, insufficient sleep across the lifetime is becoming one of the most important lifestyle factors determining whether or not you will develop Alzheimer's disease. This is an incredibly hot topic now. And it is bi-directional. What we now understand is at night during deep sleep the brain actually cleanses itself of toxins that have been building up during the day. And it is important that people realize that wakefulness is low-level brain damage. And I don't mean to be alarmist in saying that. It is simply a scientific fact. From all of this metabolic combustion and activity that happened when we're awake inside of the brain you build up excretory products just like in the rest of your body.

And this system in your body, the sewerage system, is called the glymphatic system. At night is when that glymphatic system kicks into high gear. And one of the things that this system clears out at night is this toxic protein called beta-amyloid, which is one of the leading factors that we believe causes Alzheimer's disease. Now we realize why insufficient sleep can set you on a trajectory path towards Alzheimer's. Because if you're not getting the deep sleep that you need throughout your life, you're not cleansing the brain of that toxic protein. Then we made a discovery that where that toxic protein builds up is not just [in random places] all over the brain. The Alzheimer's protein amyloid will actually develop in some parts of the brain and not in others. And sadly, the parts of the brain that it targets early on and most aggressively are the same centers that help generate that deep sleep that I was telling you about. So it actually helps cleanse the brain of amyloid. So it is a vicious cycle. And we now understand that if you don't get that deep sleep at night, more of that toxic protein builds up, and it builds up in these deep sleep areas so you can't generate the deep sleep even if you allow yourself the chance to get it. So more of that toxic protein builds up and prevents us from getting the deep sleep that we subsequently need. And through this sort of spiral, it leads to what we know is an accelerated trajectory. That is one of the areas that is exciting for us right now.

Of course, one of the other features of that discovery is that there is a silver lining—in making this discovery that sleep is a new missing piece in the puzzle about Alzheimer’s. [But it’s] not the only one. Please don't think that. There are many factors we know that contribute to Alzheimer's. But sleep seems to be one unlike many of the other factors—changes, for example, in the blood flow dynamic of the brain or the chemistry of the brain—sleep is a particularly treatable target. We can actually do something about sleep. It is very difficult for us to change blood flow in the brain right now. Modern medicine doesn't have the technology to do that. But we do have some new methods to change sleep, and one of the ways that we’re exploring is by electrical brain stimulation We've been doing some of this work and other groups in Europe have pioneered this method, too. We’ll try very small amounts of electricity in the brain. So small you don't feel it. But if you pulse that electricity in time with those deep sleep brain waves I was describing, almost as if you're singing in time with the natural rhythm of the brain, in young healthy adults you can amplify the size of those deep sleep brain waves. And you can almost double the amount of memory benefit that you get from sleep as a consequence.

So the question now is. can we translate the same techniques into older adults and those with dementia and give back that sleep? I should note for callers that it is important to note the potential limitations of sleep medications. It is a very touchy subject, but I do want to address it.

Sleeping pills are not advised for the long term, and in fact, they are not advised as the primary method for treating poor sleep. Sleeping pills do not produce naturalistic sleep. If I were to show you the electrical read out of your brain while you are taking sleeping pills verses natural sleep, they are not the same. Those sleeping pills have been commonly called the sedative hypnotics and for good reason. Sedation is not sleep. Now I'm not going to argue that when you take those sleeping pills that you are awake at night. You are not. You are certainly not awake. But to suggest that you are in naturalistic sleep is equally a falsehood. And now there's some quite damning evidence of the use of sleeping pills and increased risk of mortality and increased risk of cancer. People who would like to read more about this topic, about the dangers of sleeping pills, please Google Daniel Kripke. Or Google “the dark side of sleeping pills.” Kripke has a website that will describe to you the dangers of sleeping pills.

There is hope here. There's a new method called cognitive behavior therapy for insomnia for anyone having sleeping problems. You can just Google that—CBT. It is just as effective, if not more effective, than sleeping pills. You work with the therapist. It doesn't require drugs. But better still it’s much longer lasting than sleeping pills. One of the problems with sleeping pills is that you start to use them and if you stop you have what's called an insomnia rebound effect which is that you not only go back to having the poor sleep that you had before but your sleep is even worse due to drug tolerance and drug expectation.

So we're looking at non-pharmacological ways to cure sleep in the elderly. We are not using drugs because right now the evidence isn't strong enough to prove that they are beneficial. I'm not anti- drugs. Please don't think that. I work within the drug industry. If we can find a drug that does improve sleep, and we can scientifically prove that, I will support it. It's just that simply right now we haven't gotten there yet.

Mila from UK: What's one thing that we can do to salvage that lack of sleep in our older age? And why is it that some people have dementia and Alzheimer's and others don't? Does it mean that those who do have it have lost valuable sleep in their lifetime?

Matt: Two great questions. Firstly, in terms of sleep as we get older, there are several things that we can do. These are things that we call sleep hygiene or the principles of sleep hygiene. If you just Google sleep hygiene you will get a list of these things. And they are helpful across ages and they are helpful for the elderly.

Firstly, you can try to help regulate your rhythms. As you get older you actually start to regress back to childhood in terms of your sleep preference. You want to go to bed earlier and wake up earlier. And that's a problem because a lot of older adults don't want to go to bed around 8 or 9. They want to be around, have an active social life. Maybe stay up with the grandkids and family members. But they try to adhere to a regular sleep schedule waking up at the same time and going to sleep at the same time everyday.

The other thing that older adults commonly do, that they make a mistake on, is that they fall asleep in the afternoon and evening, and that is ill-advised. So sometimes when I meet my older clients in the study I'll ask, “do you nap during the day?”

And they all say “no, I rarely nap.”

And then I'll say, “you know sometimes when you're watching TV at night do you nod off?”

And they will say, “Yeah, sometimes I fall asleep.”

Well, that's a nap.

Here is the problem with that behavior. During the day when we are awake we build up something called sleep pressure. There is a chemical that builds up. The chemical is called adenosine. The longer you are awake, the more adenosine builds up. The more adenosine that builds up, the sleepier you feel. And after about 16 hours of continued wakefulness, you are usually so sleepy that it's time to go to sleep. And you fall asleep naturally and easily.

When we sleep at night it is like a pressure valve on that cooker. We release and remove all of that adenosine. We clear it out. And then we wake up the next morning feeling refreshed, because we've removed that adenosine, that sleep pressure.

And here is now the problem. If you stay awake during the day like all us adults, and you're building up all this sleep pressure and ready to get a full night's sleep, and then you fall asleep on the couch or you go to the movies and you fall asleep, now you've released that sleep pressure or some of that sleep pressure. Even just a couple of minutes can relieve that sleep pressure. So no wonder then you find it difficult to fall asleep at night or stay asleep throughout the night. So be really mindful of unplanned napping. And falling asleep on the couch is napping.

The three final things I would say for elderly individuals: firstly, when you go out in the morning, get lots of bright light and try not to wear shades. Make sure you have sun protection—a hat or SPF is good, but don't wear shades in the morning. Get lots of light. Suppress your hormone called melatonin. Melatonin is a hormone. It signals darkness to your body, and when you block it with light which is what happens--daylight helps put the brakes on melatonin--it makes your body realize that it's no longer darkness, and it wakes you up so that you feel good and alert in the morning. But then what we need to do is decrease our light exposure throughout the afternoon and evening. So that now if you go out for a walk in the afternoon now is the time to put shades on. Try not to get too much bright light exposure in the afternoon and as you go into the evening, try to cut down on screen time. People with televisions in their bedrooms tend to sleep worse than those who don’t. People who use iPads or iPhones an hour before bedtime tend to have considerably worse sleep than those who don't.

Caffeine too, by the way--please avoid caffeine after midday. That is critical.

The last thing for older adults is medications. Some medications that older adults take for hypertension, for example, actually prevent sleep at night. So maybe see your primary care physician and ask about not just what medications you are on but the timing of the administration of those medications because sometimes people take the same medications, but it's just about when you take them that will help you sleep better.

Parniti: Why do we sleep with our partners? Often sleep is compromised [by] other people. Is there a biological or evolutionary benefit to sleeping or to not sleeping alone? I have a difficult time adjusting to Daylight Savings Time as I have an early- bed, early-to-rise schedule. Do you have any tips on adjusting to the time change every six months?

Matt: So two questions there. So how are we supposed to sleep as a species? If you look at cultures that are untouched by electricity, many of them are actually co-sleepers. They all sleep as a community or group. Whether or not that is the best thing for us now in modern society is a completely different question. We shouldn't necessarily adhere to that sort of classic hominid curtain. And the reason is this. Firstly, the frequency of sleep disorders in industrialized nations is astronomical. About 70 million Americans now suffer from some sleep disorder. And there are over a hundred types of sleep disorders.

If you look at these cultures that are not affected by electricity those rates of sleep disorders are usually less than 1%. What that means is that when sleeping as a group, the group tends to sleep largely at the same time. They are driven by dusk, by the sun, and by dawn. So everyone has a much more stable regular common sleep pattern. Now that is not true in industrialized life. First, we have higher rates of sleep disorders and people are going to bed at different times for different social and professional reasons. As a consequence, having a partner in your bed who is off your schedule and sleeping at a different time and/or has a sleep disorder—snoring, sleep apnea, tossing and turning with insomnia—has a profound impact on your sleep, too. And we now know that between some 40% and 60% of couples will either not sleep in the same room or they will start sleeping in the same room but then end up sleeping in different locations, either on the couch or in a spare room or in a guest room. So now there is a revolution, largely unspoken of because of the stigma, which is called the wonderful sleep divorce, where people are deciding to go to sleep in different rooms where they sleep better. And the stigma around this of course is that it signals that you're not having a healthy relationship if you are not sleeping in the same bed then perhaps you are not having a physical relationship. In fact the opposite is true if you look at the data. People who get more sleep are more physically engaged in their relationships than people who are not getting sufficient sleep in part because it regulates many of our hormones and our energies that are critical to that side of nurturing physical relationship. So that's a big topic, and I think we'll see a continued recognition and acceptance of it in the community.

Coming onto Daylight Savings Time, it is a problem. It is very hard on the body when it shifts between time zones. It cannot make up time zones as quickly as we can now travel with this thing called the jet airplane. And it causes a mismatch between the biological clock and the new clock time in the time zone. That mismatch causes what we call jet lag. Everyday that you are in a new time zone your biological clock, your circadian rhythm, adjusts by about 1 hour of time. So if I fly back to United Kingdom, which is eight hours ahead of us, it is going to take me eight days to catch up an hour each day. Now for Daylight Savings Time: what that means is it's going to take a little bit of time to catch up. The best way to try and deal with Daylight Savings Time is to use an alarm to gradually titrate. It is almost like coming off a drug. You're at full dose and you come down to 80% dose and then you come down to 60% dose. If you were in the springtime where you are losing an hour sleep, and we'll have to wake up an hour early, in the weeks before, try to start waking up 10 minutes earlier--that's six or seven days before--then 10 minutes earlier the next day and 10 minutes earlier the following day. And just gradually move yourself sliding on that sliding scale to an earlier and earlier waking time rather than doing it all in one sitting on that one night of time change. You will find it easier to do it in that gradual build-up fashion.

Amit: I have a good friend of mine who lives in the United Kingdom and when she comes to visit her family in California, she stays for a couple of weeks. Literally about a week or so before—she has two young girls—she starts to move into the California time schedule so it isn't as much of a hectic transition when they get over there.

Matt: It's just simply understanding how sleep works. There's so much information out there. I'm actually publishing a book next year. My first science popular book on sleep and it's really aimed at the lack of understanding  [I’ve seen] from doing public speaking and radio and television interviews. Scientists have done such a poor job of getting the science and the good work on sleep out there in a digestible or meaningful way. And society’s sleep neglect and society’s apathy towards sleep in part is because people like myself have failed to communicate with the public. That was one of the reasons to motivate me to put pen to paper and write this book and get research on sleep out there. I hope this call helps on those lines, too.

Aryae: So Matt, I have another question, sort of shifting frames again. You talk about the global sleepless epidemic as the greatest public health challenge that we are now facing, and hearing what you are now saying, that makes a lot of sense. Before the call, I was curious and Googled public health challenges, and I got all kinds of lists. Here is one from the Centers for Disease Control and Prevention (CDC) that was published in March of this year. They have on the list alcohol-related harms, food safety, healthcare-associated infections, heart disease and strokes, HIV, motor vehicle injuries, nutrition, physical activity and obesity, prescription drug overdose, teen pregnancy, and tobacco use. They don't have sleep on their list and I didn't see it on other lists. So what do you say about that discrepancy?

Matt: What is fascinating is that almost every one of those large public health concerns is directly related to insufficient sleep. So, for example, we know that insufficient sleep is tied to high rates of cardiovascular disease, the calcification of the coronary arteries,  hypertension, and stroke. We also know that sleep loss is causally related to obesity. It is also causally related to diet and disease. Sleeplessness has a profound impact on your immune health and in fact you can go to so many of the classic immune disorders even the common cold. People who get six hours of sleep or less are between 50% or 60% more likely to catch a cold than those who sleep more.

Cancer is now strongly related to insufficient sleep. That includes cancer of the bowel, cancer of the prostate, and cancer of the breast. So much so that in fact the World Health Organization (WHO) recently classified any form of nighttime shift work as a probable carcinogen. Set jobs that disrupt your sleep wake rhythm are cancer-inducing, that is how strong the evidence is right now.

We now know that drowsy driving causes more accidents on our roads then either drugs or alcohol combined. And yet we spend a fraction of 1% of our public health policy budget on educating people about the dangers of insufficient sleep.

Risk-and-reward behaviors are intimately tied to insufficient sleep, from risky behavior to drug addiction and drug-taking and teenage pregnancy. We've done a lot of work in this area, too, particularly on adolescent youth. You shorten their sleep, they become much more risk-taking and sensation-seeking. They engage in behaviors that are high-risk behaviors.

So every one of the conditions on that list has a link to insufficient sleep. So why sleep is not on that list is so desperately sad and striking to me. That is why people like myself need to come out and become much better sleep ambassadors. We need to go to places like Capitol Hill. We need to go to Washington. We need to not just go there waving our hands saying look at this problem. We need to come up with 21st century new visions of solutions. And that is one of the things that I speak about in the forthcoming book. And is one of the things that I am trying to now push very hard with a number of quick advocacy policies. We need to change society for the better. We need to reorient and prioritize.

Aryae: So what you're saying is that this is a public health challenge which is behind many of the other public health challenges and that this meta public health challenge needs to get on the radar screen?

Matt: If we bend, the downward arrow of insufficient sleep in society--and it really is only going in that one direction--if we bend that arrow so that people start sleeping more all the health dangers and concerns that are on that list will change as a consequence. We know this from interventions studies. If you treat sleep disorders or newly regularize sleep or you casually improve sleep in an individual, those health metrics also improve. In people who have sleep disorders, for example, which lead to cognitive impairment and Alzheimer’s, if you start treating those sleep disorders like sleep-disordered breathing or sleep apnea, you can actually delay the onset of cognitive decline by somewhere between 5 and 10 years. So there's a causal intervention that staves off ill health and dementia. So if we rectify sleep, we rectify the brain and the body--it is almost like a Swiss army knife of health. I've heard people say that sleep is the third pillar of health along with diet and exercise, and I actually disagree. I actually think that sleep is the very foundation on which those two other pillars of health sit.

And we know this, too, that if you erode sleep, dieting becomes ineffective; physical exercise also is diminished. It's where everything starts. A good night of sleep provides nothing more then the greatest recharge to your waking life. More than anything else that we know of right now.

Aryae: Thank you. Yes that makes sense. Something that you and I had discussed earlier and that I've been very curious about, is how is the way any of us might be getting a night's sleep affected by where we live, by our cultural background, by a socioeconomic status?

Matt: Such a wonderful question. This is another area that is getting some light. I've spoken a lot about how and why we sleep from a biological angle or from the physiology of our brains and our body. Of course they are strong determinants. Our biology is a big determinant of how we sleep. But sleep is also determined socially. It is a social construct. Just think about it. Like who are you? What is your social standing? And do you think that makes a difference with how you sleep?

For example, take someone who is of a low socioeconomic status. What is their sleeping condition like? Do you think that social status changes their opportunity to get good [night’s] sleep? And the answer is of course yes. The answer comes in a variety of different forms. There are different factors that there are pressure on sleep in low socio-economic classes. There's a deep sleep disparity right now. But it is not just biologically caused. It is socially caused. Firstly, one of the principal reasons is your sleeping situation. If you live in a neighborhood where there is high crime, for example, then that psychological threat of danger will prevent you from getting a full and normal night of sleep. And this we know from lots of good studies—that psychological weight of danger if you're in the neighborhood where there is constant violence or there is constant threat of burglary or home intrusion, imagine how well you would sleep at night. Not particular well, I'm sure.

The other thing is how work pressures sleep and grabs sleep like a vice grip and squeezes it from top to tail. What I mean by that is a lot of low-paying, low socio-economic employment is in the service industry right now. In the service industry, jobs tend to start very early in the morning. And as a consequence, people from low socioeconomic families also often don't have a car, so they are taking public transport. So to get to those early jobs, which can sometimes start at 5 or 6 in the morning, they may have to wake up at 4 o'clock in the morning to get to those jobs. And then when they come home sometimes they may have two jobs--one that goes from the afternoon into the evening. Often these are families that have just one parent. You have this huge burden of child care in the evening and then you are waking up at 4 o'clock the next morning to get to your job again. So there is an economic and employment disparity that forces poor sleep in these communities.

Amit: Wonderful. Thank you. I'm going to go to one of our first callers.

Caller: Yes, I have a question. Thank you for pointing out the problems with sleeping pills. I've got some pills that I'm taking for anti-depression and other medications and they are messing with my sleep. And I have to take Ambient to go to sleep. And if I don't take it I do have that rebound kind of insomnia. What kind of suggestions do you have?

Matt: Yeah, so I would say that obviously it is important to be guided by your physician, and as I mentioned I am not an M.D. I'm not here to give medical advice, but the wisdom out there right now is to go see a board-certified medical doctor who specializes in sleep problems. Sometimes even regular general practitioners are not up-to-date on the latest research in medicine. It's striking when you look at the medical syllabus, by the way, how much education our doctors get regarding sleep is actually not enough. It is not anywhere near sufficient. So I would think about if you're having problems with sleep and the sleeping pills aren't serving you well, I would perhaps seek out a referral to a board-certified sleep medicine doctor. If you are in California, there are some great sleep clinics. University of California San Francisco (UCSF) has a great sleep clinic. Stanford has a great sleep clinic. If you are not, please go to the National Sleep Foundation. Just Google National Sleep Foundation. And on their website you can actually find a link to locations where there are great sleep centers and you can find a particular doctor who will help talk you through the alternatives. But right now one of the strongest alternatives and the first line treatment of defense for insomnia has now shifted to cognitive behavioral therapy and away from short-term sleeping pills.

Caller: Thank you; it is long-term sleeping pill use.

Matt: Yeah, and that is not unusual right now. According to the American Board of Sleep Medicine, the long-term prescription use of sleeping pills is not advocated, as I currently understand the recommendations. Maybe that is something you would want to take up with your general practitioner and perhaps with a board-certified sleep doctor.

Caller: Okay, thank you so very much.

Matt: I hope you find the solutions to sleep.

Caller: I've been listening to your whole presentation. I've been taking a lot of notes. I'd like to offer myself to you as a study subject for you. I've been studying and perfecting. I think I've become a sleep master. I'm not trying to sell me or my method or anything in any way. But I have really, really learned about sleep. I can go to sleep and decide when I want to wake up, even though they say that's not what you're supposed to do. And it works for me.

I'd like to ask you a question. Besides offering something to you. I'd like to communicate with you because I have discovered things that I don't hear anyone talk about, about the formula of sleep. I'd like to share it with the world. I've become a sleep master.

As I'm writing you're saying some things that are crucial. But sleep does not cause disease. That disease is there and then we don't get to the healing part of sleep. And it doesn't let us heal. So the disease may be caused by diet. It may be caused by stress. It could be a whole bunch of things. The sleep is crucial. To sleep properly without drugs. Natural. It's not the quantity of sleep. It is the quality of sleep that is important. So my question is what are the ingredients necessary for a good, not necessarily night of sleep, but just a good rewarding session of sleep per session?

Matt: Yeah, let me just come back to a couple of things. You make such a great admission that diseases tend to cause sleep problems. We know this. That there are a number of conditions--many conditions in fact--that can lead to the destruction of sleep. But I want to make clear that it is bi-directional. We know that if you take an individual, or there is lots of evidence even in animal studies, that if you causally manipulate sleep you can trigger disease. So it works both ways. It is a two-way street. It can cause disease and sleep disorders.

In terms of ingredients I would say that the sleep hygiene principles are the best principles that you can use to obtain a sound night of sleep. Your point also is really an essential one. It's not just about sleep quantity, it's also about sleep quality. It's not one or the other. It is both. You can't simply just have great sleep quality for four hours and then short change the rest of sleep and get away with it. But nor can you sleep for 10 hours but have very poor fragmented sleep and get away with it, too. The research we now have is really quite definitive. It is both quantity and quality.

With that being said, there are really several critical sleep hygiene practices. Firstly, try to stay away from caffeine after midday. The second is wake up at the same time of day if you can. If there's a single most prescribed piece of advice from sleep doctors it is that. Wake up at the same time of day each and every day. And do not change on the weekends. Do not sleep in one pattern during the week and then sleep in a different manner during the weekend. That is critical, too.

The next thing is to try to stay away from alcohol in the evening. Many people drink alcohol because it helps them fall asleep. That is a misnomer. Alcohol like sleeping pills is a sedative. And alcohol will sedate you but it won't keep you asleep. It will fragment your sleep. You will wake up many times throughout the night. And it also blocks your dreams. So stay away from alcohol.

The third thing is avoid napping during the day. We talked about that.

The next thing is light. Lots of bright light during the morning. Try to cycle down your light in the evening. Especially blue light devices. The next thing is to find a relaxation routine before bed. Many people in this day and age, the only time we get to reflect on what is going on inside of our heads is when it hits the pillow and that's the last thing that we should be doing. To try to spend a little bit of time winding down. Take a bath. Baths help to actually drop your core body temperature. I know that sounds strange. You get in the bath you warm up. You get out of the bath and you drop your core body temperature. That drop in core body temperature allows you to fall asleep quickly. You need to drop your core body temperature to initiate sleep. It's the reason why it is always easier to fall asleep in a room that is too cold than in one that is too hot. Decrease the thermostat settings. Most people don't realize that a comfortable temperature for sleep is usually between 65 to 70 degrees. Most people have the thermostat set to too high a temperature. So try to cool down core temperature. Having a warm bath helps with that.

So those are things that help people get their good quality of sleep as well as good quantity of sleep.

Amit: Thank you for that question. We have a lot of interest from people around the world. Isabel from Germany says, “Thank you; I've been looking forward to this call. I'm one of those people that is sleeping less and less and is that reversible? I've done this for years. Is there any benefits to changing now rather than in my late sixties?”

Matt: There is always benefit. And one should always hold out hope to try and obtain the very best sleep that your brain in that time of life is capable of. As I said some of these sleep hygiene principles--you can just Google sleep hygiene--should really help your biology at this stage of life, which is about finding the best chance of producing the best quantity and quality of sleep that you can have. So I think there is usually always room for improvement and individuals even in later life there is always room for improvement.

Also speaking with your physician or a board certified sleep specialist to look into perhaps things like chronic pain that you're suffering, other conditions that can contribute to insufficient sleep things like anxiety, depression. You manage those. If you manage your pain in a better way you can actually get better sleep.

Thinking about trying to decrease medications that increase urination at night. That’s one of the things we have problems with when we get older: we tend to have to go to the bathroom at night and it is hard to get back to sleep. Another thing to not be concerned about, if you wake up at night and you're having trouble getting back to sleep first try not to fret. Secondly, don't stay in bed. If you haven't fallen asleep when you get back into bed after about 15 or 20 minutes, don't stay in bed. Instead, get out of bed. Go to a different room. And in dim light just do something that is relaxing. Like reading a book that is not going to cause your wheels in your mind to start spinning. Don't get on an iPad or check email. Stay off technology. Only when you feel tired and sleepy then come back to bed. And the reason for this is that your brain is an incredibly associative device. If you stay in bed and you are awake, your brain starts to link and associate and make connections between being in bed and staying awake, rather than being in bed and falling asleep. And you need to break that association. So just accept that tonight is not going to be a great night. Tomorrow you're going to feel a little tired because you have woken up and you couldn't get back to sleep quickly. But try not to fret. Get out of bed. Do something relaxing. When you feel sleepy come back to bed. Fall asleep. Break that association. Don't sleep too long the next morning, because then you will get into a cycle where you are waking up later and later and now you can't fall asleep at night at your normal bedtime because you haven't been awake long enough to fill all of that sleep pressure. So these are things that can really help. So try to follow the sleep hygiene tips. It should help you later in life.

Kozo: Hi Matt. Thank you for this wonderful information. My name is Kozo. I'm calling in from Cupertino, California. I was really struck by when you said that sleep and bad sleep patterns can actually cause disease. I'm wondering if you know if there's any research being done on sleep being actually a therapeutic for disease. So let's say you are diagnosed with cancer, is there any research being done where they require people to sleep in a certain way for a certain amount of time and then check and see if that affects the disease?

A related question, is there any movement or any research being done on sleep and hospitals, because it seems to me like you said sedation is not sleep. And in a hospital environment it seems like sleep is almost impossible. They come in and check on you. You have a roommate. They are moving things around. They have lights on. I'm just wondering if that is causing more disease or causing more mortality?

Matt: So the answer to both of those questions is an emerging area but the movement isn't really in full swing right now. The evidence is concrete. We have good evidence and clinical studies in animal models that suggest that if you bi-directionally perturb sleep you can accelerate or retard certain diseases. A good example of this is cancer. If you are fighting a battle against cancer and not getting sufficient sleep, we now know that the cancer will grow more aggressively and more quickly. So people are now trying to think about prioritizing sleep as an agent that will aid in in the fight against cancer. Some really powerful and quite disturbing animal studies are out there showing that if you are short changing animals who have cancer of sleep, that cancer can increase in its speed and size and growth by 200%. So the evidence is that sleep is causal and bi-directional. It has forced people like me to try and advocate to medicine and doctors that we need to start prescribing sleep. Not prescribing sleep medication but prescribing sleep as the elixir of life, as a panacea for good health, and perhaps one of the best Archimedes lever that we can think of for actually brute forcing health under the attack of disease. And we will see more of that in the future.

In terms of sleep in the hospitals, you are absolutely right. There's now a slow but growing recognition that it is a major problem. The place where I would argue you need a good night's sleep the most is perhaps the last place that you get it, which is a hospital. And one of the things that I write about in the forthcoming book, is why don’t we do what we do on transatlantic flights. We give people a free eye mask and a free pair of earplugs. Add a small cost and it would help significantly with improving sleep. Now we've even seen evidence in neonates in the Intensive Care Unit that if you regularize the sleep they will exit out of the Neo Intensive Care Unit in half the time. It's a dramatic improvement in health. So, the short answer is yes to both of those, but more needs to happen on both of those. I hope that helps.

Kozo: Thank you for being a vanguard in both those realms. You are doing a wonderful service. Thank you.

Matt: Thank you. It is my privilege. I feel like it's an honor to do that.

Albert from Oakland: Thank you so much. So, what I'm hearing is that a nap during the day is not really encouraged, which is contrary to a lot of older stories of certain cultures that may have benefited from the tradition of a siesta. Or if you take a look at children for example napping is encouraged for them for brain development. So is there a shift that happens at a certain age where it is no longer required or needed?

Matt: So let me be very, very clear about naps and their use. Firstly, children should be napping. Children very early in life are what we call polyphasic in sleep, which means they have many phases of sleep. Then they become biphasic, which means they have an afternoon nap and then they sleep at night. If you do look at cultures that are touched by electricity, many of them are biphasic. They will sleep six and a half or seven hours of sleep at night and then they will have a siesta-like phase in the afternoon. We may be in modern-day societies not sleeping in the way we are naturally programmed. And I think there's good evidence for that. Which could lead to the suggestion that we should be napping. But here's the problem. Most people are not able to regularly nap. And it is in that context that sleep medicine now advocates against napping.

So if you can regularly nap during the day, day after day in a very stable manner and you can do so early in the afternoon, then napping is advantageous only under the condition that you are not having problems falling asleep at night. But if you cannot nap regularly then it is not adviseable. Secondly, it is not advised that you nap later in the day. And finally, for older adults, if you are napping and having problems with sleep at night it is strongly advocated against that you don't nap during the day and that you try to just push all of that sleep pressure into getting a good night's sleep throughout the night.

So children—great to be napping. It is natural. Human beings, innately, we may be biphasic. We may be born natural nappers throughout our adult life. It is just that in modern day society very few people can nap regularly and if you can't then it can be problematic especially late in the day.

Amit: Do natural supplements support sleep like calcium and magnesium or melatonin?

Matt: Sadly the evidence isn't particularly strong in clinical trials. If you are in a severely nutrition deficient state then that can have an effect on your sleep and I want to be clear about that, but many of the homeopathic medications and even melatonin--and this is melatonin in the context of once you're in a new time zone and you’re stable and you're not suffering from jet lag--homeopathic medicines and melatonin for the most part have not held up under clinical trials to be any more efficacious than a placebo. Let me be clear about that, if you are taking melatonin or some kind of a homeopathic medication and you feel as though it helps you sleep, my recommendation is keep taking it. And the reason is this that the placebo effect is the most reliable effect in all of pharmacology. And what that tells us is that there is such a thing as mind over matter, and science is now grappling with this. It is acknowledging the placebo effect and that we should take advantage of it. So I don't mean to be dismissive of people who are finding these things to be helpful. All I would say is that the help that they provide does not seem to be anything above and beyond that of a placebo at least on the science that we have right now.

Caller: Hello my name is Suzanne. I'll try and be fast. Our new president concerns me in that he stays awake tweeting all night and a lot more. Is he going to be able to judge adequately not sleeping? He boasts about that.

Matt: Great question. And it strikes at the very heart of one of the biggest problems with sleep. The answer is no he's not going to be able to judge based on the scientific evidence. The fact is this your subjective sense of how well you are doing when you haven't been sleeping enough is a miserable predictor of objectively how poorly you are doing with insufficient sleep. What I mean by that is you don't really know that you're sleep deprived when you're sleep deprived. The analogy is a drunk driver at a bar who has had five or six shots of vodka and a couple of beers and who may pick up their keys at the end of the night and say, “I am fine to drive home.” And your response is, “No, no, no, I know you think you're fine to drive, but trust me you are, objectively speaking, certainly not.” It’s the same with sleep deprivation, and we've got great data demonstrating this. That's the reason why people will say to you, “No I'm actually one of those people who can survive on six hours of sleep or less.” That is sadly not true based on the scientific data of about 17000 studies; the number of people who can survive on six hours of sleep or less without measurable impairment rounded to a whole number and expressed as a percent is zero.

Suzanne: Oh goodness. Thank you so much for that. And bless us all.

Caller: Thank you Matt for sharing so much info. I’m just blown away. This is Mish in NY and I’m now questioning the benefit of my sleep pattern after listening. I’m a senior, I fall asleep as soon as my head hits the pillow, I sleep straight through for about 4 hours. I wake up between one and three times for a few minutes, go back to sleep right away each time, and then wake up as soon as my feet hit the floor. Is there any quality to the sleep pattern?

Matt: You're worried about the waking up throughout the night-- is that your concern?

Mish: Yes.

Matt: As long as you are finding that you're able to fall asleep quickly after those awakenings without a problem, and secondly during the day if you are feeling restored by your sleep and you're not feeling as though you're nodding off, or you're lacking in energy, then the chances are that the sleep you're getting is sufficient. But if it's not, or you're concerned and don't think your sleep is sufficient, definitely do go and see your doctors and let them know about those sleep problems. But from the sounds of it, it doesn't seem like you're suffering one of the two forms of insomnia. One of them is called sleep onset insomnia which is having trouble falling asleep and the other is sleep maintenance insomnia which is trouble staying asleep where you wake up throughout the night and find it difficult to fall back asleep. It sounds like you do wake up, but you're able to get back to sleep.

Mish: Yes, usually right away, and I do go back into dreams.

Matt: Yes and as I said earlier in the call, the second half of the night it's much more deep, rich sleep whereas the first half is much more dreamless sleep so that makes sense. It shouldn't be concerning.

Mish: Thank you so much; I feel much better.

Matt: You’re welcome

Amit: I'm going to go to one of our online questions: “Do you have any recommendations for getting smartphone apps for monitoring the quality of our sleep? Have you heard of things like motion eggs and are there techniques for getting dream sleep and non-dream sleep?

Matt: It's a little bit of a mixed bag out there in terms of these sleep assessment tools, and I should also mention full [disclosure] that I work with a start up company up in San Francisco as the Scientific Advisor. But I think right now the apps that track your sleep are perhaps not particularly accurate. I think we'll get there very soon, and in the next two to three years, we will have good sleep-tracking devices, and I'm excited about that because right now technology is one of the biggest enemies in the bedroom for sleep. But I think it's going to be technology that is our salvation. And the reason is this, there's a common adage in medicine which is, “What gets measured gets managed.” And for so many of us for so many decades we've never really had a handle on how we are sleeping because we couldn't measure it apart from our subjective sense of what time we turn the lights off and what time we woke up--and that's not a very accurate rendering of our sleep. I'm very hopeful that soon we will have wearable technology or technology in the bedroom that accurately tracks our sleep. And once we take control of our sleep we will be able to better manage our sleep, and I think that's fast going to happen and it will only be good for society.

Amit: For our final question from Pranidhi, “What do you think of advocacy for institutional change in this realm? How do we encourage our schools and our work schedules to prioritize sleep? When you think about the difficult personal circumstances of certain people, whether they are single parents or the professional obligations that might come into play or familial obligations if someone was just limited by the mere fact of that there are only twenty-four hours in the day, are there ways to maximize the efficacy of the short amount of time of sleep or are we just out of luck?”

Matt: Certainly, we're out of luck. There is just no way to cheat the brain and the body out of sleep. One way or another it will catch up to you whether it's chronic sleep deprivation across a lifetime, leading to chronic disease and ill-health, or it's the tragedy of mortality and this brings us back to road traffic accidents. When you are not sleeping, you are having micro-sleeps at the wheel. Sometimes your eyelids will partially close. Now at 65 miles per hour if you have a micro sleep that usually lasts just for one or two seconds, at 65 miles per hour that means you'll drift from one lane to the next. So at that moment for those two seconds there is a one ton missile traveling at 65 miles per hour and no one is in control. And that can lead to fatal consequences not just for you but for those around you on the road. So one way or another not getting sufficient sleep will come back to you unfortunately. There’s sadly no way to short change it. It's non-negotiable; it's a life support system. It's a biological necessity, and it’s Mother Nature’s best effort yet to counter death.

Caller: My name is Alissa; I am in Seattle. I work sling shift so I do have an odd schedule but I try and keep my sleep regular. And this is for all the people who can't do what you describe and go to bed an earlier time--is that still okay as far as still keeping your sleep regular but working at odd, different times?

Matt: Right now shift work is a real problem and working at different times of day causes that normal window of sleep to slide across the 24 hour clock face. That really isn't an optimal way to be falling asleep. Right now the advocacy in shift work is, if you're on a shift, try to maintain that shift for long durations of time, and then come off and have a long period of recovery, and then go back on that stable shift. The biggest problem with shift work is having shift work that is inconsistent. So trying to find consistency within shift work is perhaps right now if it really has to happen--and for many people--for some people it does--as it’s your job--we are serviced by people, doctors, pilots, emergency service personnel, nurses, many people service us as a society by way of shift. Now technology is going to help try to limit the burden some, but people still make that sacrifice for us and we need to make it better for them and this is one of the ways that seems to be best. If you do need to do shift work, maintain that stable shift, that off normal natural rhythm shift, for a long period of time and once that shift ends give yourself a long period of recovery before you have to go into that same shift again. Right now that is the best advocacy that medicine has.

Caller: So basically what you're saying is get a good night's sleep at a different time, and I'm not shortening my sleep an hour; it's just that I sleep at a different time.

Matt: Unfortunately if you give yourself eight hours of sleep during the day versus eight hours of sleep at night, the sleep you get during the day is not the same that you get at night; it is more fragmented, and it's not as deep quality of sleep and it doesn't necessarily contain the same stages of sleep. And the reason is that biologically you're not designed to sleep--we are humans, we’re not designed to sleep during the day--other species are, however--but we are not. We're not nocturnal species; we are a diurnal species. And so the recommendation is make sure you do give yourself eight hours, that's critical, but do realize that it's probably not going to be as good a quality as eight hours of sleep during the day as it would be eight hours at night.

Caller: I see, so if I go to sleep at 2 and wake up at 10 or whatever, that's not really the best thing. I should go to bed earlier if I could.

Matt: Just a little bit of a caveat on that: everyone has their own circadian preference, the fancy name is pronotype which means some people are owls, some people are larks. Some people like to go to bed late and wake up late. Others like to go to bed early and wake up early. It's a natural variation and it’s determined by genetics. It also changes across the lifespan, of course. If you're one of those people who likes to go to bed late and wake up late then the schedule that you just described, of going to bed at 2 a.m. and waking up at 10 a.m., may actually be fine. It fits perfectly with your biological rhythm. But if you're someone who is a lark then you would like to go to bed at 10 o'clock and wake up at 6, then going to bed at 2 a.m. and waking at 10 is not going to be optimal for your biology.

Caller: Thank you; that makes a lot of sense, and I think that will make sense for a lot of people. I really appreciate it.

Matt: I hope you sleep well; thank you.

Amit: This is a very hot topic. We really appreciate you coming to share with us today. As a community how can we support your work?

Matt: I think I would just ask people to actually propagate the good work. And rather than necessarily support my work try and learn more about sleep and advocate more the critical thing for us to do as a society is to get rid of the stigma of sufficient sleep. This is one of the major problems right now that we face is in the civilized world is that we have associated getting sufficient sleep with this thing called laziness. That we think people who get eight hours are slothful, and they're not productive and the opposite is true. So as a society we need to be proud of our sleep; we need to reclaim our right to a full night of sleep without embarrassment and without that terrible stigma of laziness. And in doing so, we may all feel what it's like to be truly awake during the day. So please don't chastise others for getting sufficient sleep. As parents we shouldn't chastise our children because that parent-child transmission of sleep neglect is powerful and it is problematic. That's the only support I would ask for.