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The World’s No.1 Sleep Expert: The 6 Sleep Hacks You NEED! Matthew Walker — Transcript

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0:00When you're struggling with sleep in the
0:01middle of the night, and you're wide
0:02awake in the last hour before bed, try
0:05this experiment.
0:08I'm I'm sold.
0:10Matthew Walker.
0:11Neuroscientist and best-selling author.
0:13And one of the world's leading
0:14researchers in sleep science. It's going
0:17to blow your mind.
0:18There's a global sleep loss epidemic
0:20shaped by this thing called the modern
0:22world. What society wants is that you're
0:24either producing or you're consuming. In
0:26fact, the CEO of Netflix is stating was
0:30that we ought to commit war against
0:31sleep. We have this mentality in
0:34business. Less sleep equals more
0:36productivity. That is just not true.
0:38Insufficient sleep costs most nations
0:41about $411 billion.
0:44Jeez.
0:45Your rates of obesity, cardiovascular
0:47disease, mental health conditions, all
0:49of these things escalate. If that wasn't
0:51bad enough,
0:51Oh my god.
0:52if you're not getting sufficient sleep,
0:54then 60% of all of the weight that you
0:58lose will come from lean muscle mass and
1:01not fat.
1:03Not the muscle. How would you redesign
1:05society to help us to sleep better?
1:07So, first I would
1:10Feels like caffeine is a miracle drug
1:12with no apparent cost. Was I wrong or
1:14was I right?
1:16Wrong. Caffeine will hurt your sleep in
1:18three ways most people are not aware of.
1:21So, if you have a cup of coffee at
1:23midday, what happens is that
1:28Before we get into this episode, just
1:29wanted to say thank you first and
1:31foremost for being part of this
1:32community. Um the team here at The Diary
1:34of a CEO is now almost 30 people, and
1:36that's literally because you watch and
1:38you subscribe and you um leave comments
1:40and you like the videos that that this
1:42show's been able to grow. And it's the
1:44greatest honor of my life to sit here
1:45with these incredible people and just
1:47selfishly ask them questions that I'm
1:49pondering over or worrying about in my
1:50life. But this is just the beginning for
1:52The Diary of a CEO. We've got big big
1:54plans to to this show um to every corner
1:56of the world and to to to diversify our
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2:05if there's one thing you could do to
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2:15Means the world.
2:17Let's get on with it.
2:25Matt,
2:26I have spent the longest time trying to
2:29sit down with you on this podcast. So,
2:31I'm very very happy to spend some time
2:33with you today.
2:35And that is because your your work is
2:37now world-renowned um and it's very very
2:40important work.
2:41But,
2:43as is the case with a few of the recent
2:44episodes in this podcast, I wanted to
2:46start by asking you,
2:48in your view,
2:50what is it you do and why is it so
2:52important in your mind that you do it?
2:56Well, firstly, thank you so much for
2:58having me here and having this
3:00conversation. It's an incredible
3:02privilege to sit with you.
3:04Um
3:05why do I do what I do and why do I think
3:08it's important?
3:09Um
3:10sleep, I would argue, is the single most
3:14effective thing that you can do to reset
3:16your brain and body health.
3:19And I don't say that flippantly. It's
3:20not as though I'm dismissing exercise or
3:23diet. Those two things are absolutely
3:25critical.
3:27But, if I were to take you, the
3:28individual, and deprive you of exercise
3:31for a day, deprive you of food for a
3:34day, deprive you of water for a day, or
3:36deprive you of sleep for a day, 24
3:39hours, and I were to map your brain and
3:42body impairments, it's not even a
3:44competition.
3:45That one night of lost sleep relative to
3:47those other things, it dwarfs The only
3:50thing I lose out against is oxygen. If I
3:53deprive you oxygen, you're going to pop
3:55out
3:56of existence a little bit quicker than
3:57you will with a lack of sleep. So,
4:00sleep to me, I think, is the elixir of
4:04life. It is your life support system.
4:07And as best we can tell, I would argue
4:09it's Mother Nature's best effort yet at
4:12immortality.
4:14And so in that regard, that's why I when
4:16I look across all of the studies and all
4:18of the data, it's so compelling to me.
4:21And part of the reason I think it's I've
4:24desperately tried and I haven't done a
4:26good job, but I've tried to offer some
4:29public mission of reuniting humanity
4:31with the sleep that it's so bereft of is
4:34because it does appear that there is a
4:36global sleep loss epidemic. If you look
4:38at the numbers, people are struggling so
4:41desperately with their sleep. So we have
4:44all of this knowledge, this incredible
4:45knowledge of sleep and how important it
4:47is.
4:48And it's a perfect storm colliding with
4:50this great sleep depression in modern
4:53society. And for that reason, I just
4:56felt as though what can I do to try to
4:58help, offer this voice and this science.
5:02And I am but a scientist and I stand on
5:05the shoulders of all of my colleagues
5:07and all of these giants in the field.
5:08I'm just a researcher, so that's a
5:10little bit about I guess who I am, but
5:13more about why I do it and why I think
5:15it's important.
5:16If I were to try and define your sort of
5:18And this I hate doing this because it
5:19requires the application of some kind of
5:21narrow label. If I was to try and define
5:23what your title is in your own words,
5:26what would that be?
5:27So I'm just a professor of neuroscience,
5:30of brain science at the University of
5:31California, Berkeley.
5:33Um I am I am not a medical doctor, just
5:36FYI for all of the things that we will
5:38talk about in this conversation. Uh so
5:40I'm just a PhD.
5:42Just a PhD.
5:43Yeah.
5:44You know, that's um
5:45incredibly humble of you, but but I
5:47would assert that you're without a
5:49shadow of a doubt the leading
5:52author, scientist, commentator, voice as
5:57it relates to the topic of sleep.
5:59And my my my question from that is,
6:02where did that begin? Like, where did
6:04that start in your life, in the journey
6:06of your life? When did sleep become the
6:09thing?
6:11It occurred to me or happened to me, I
6:14should say, when I was doing my PhD. I
6:16was studying people with dementia and we
6:19were trying to understand what type of
6:22different dementia that they had very
6:24early on in the course of the disease.
6:27And we were looking at patterns of brain
6:29wave activity. So, I was placing
6:30electrodes all over the head and I was
6:32measuring them and I was trying to
6:34differentially diagnose them very early
6:36on and I was getting no good data
6:39whatsoever. I was miserable. Nothing was
6:41was landing.
6:43And one day I went home uh at the
6:45weekend and sort of with all of my
6:47printed journals and I go to the my
6:49doctor's residence and have this sort of
6:51eggloo of journals around me that I
6:53would sit and read at the weekend. Um,
6:56and I was which probably tells you
6:57everything about my social life at the
6:59weekend if that's what I was doing, but
7:01um so I was reading these journals and
7:04it occurred to me that some of these
7:05dementias were eating away at the sleep
7:07centers in the brain and others would
7:09leave them untouched. And at that moment
7:12I realized I'm measuring my patients at
7:14the wrong time. I'm measuring them when
7:16they're awake. Should be measuring them
7:19when they're asleep.
7:20Started doing that, got amazing results.
7:23And at that point I wanted to ask the
7:25question, well, I wonder if the sleep
7:28problems are not simply a symptom of the
7:31dementia.
7:32I wonder if it's a potential cause of
7:35the dementia.
7:37And at that point I started to think,
7:38well, so then what is this thing called
7:40sleep?
7:42And what I learned is that some of the
7:45greatest minds in the past 100 years had
7:48tried to answer a very simple question.
7:51Why do we sleep?
7:53And you know, 30 years ago in fact, the
7:56crass answer was that we sleep to cure
7:59sleepiness.
8:02Which tells you nothing about you know,
8:03it's like saying, I eat to cure hunger.
8:05Well, no, you that's not the right
8:08answer.
8:09Now, 30 years later, we've had to upend
8:12the question and we now have to ask, is
8:15there any physiological system in your
8:17body? Is there any operation of your
8:19mind that isn't wonderfully enhanced
8:22when you get sleep or demonstrably
8:24impaired when you don't get enough?
8:26And the answer seems to be to be no
8:28there. So, my journey into the science
8:32of sleep really was an accident. But at
8:34that moment in time when I started
8:36reading about sleep, I utterly fell in
8:39love with the topic.
8:41And it is a love affair that has lasted
8:43me over 20 years.
8:46I think it is the most beguiling topic
8:48in all of science. I'm biased of course.
8:52Um and I will never study anything
8:54different. I know that now. I'll study
8:56it to the end of my career and until the
8:58end of my life.
9:00Wow.
9:01I've never heard anybody say to me on
9:03this podcast that they would study
9:05the same topic for the rest of their
9:07life.
9:08And you're a young man. That's a you've
9:09got a long way to go.
9:10Actually, the amount you've been
9:11sleeping
9:12It's very kind of you to say. I I wish
9:14I'm I'm moving into the foothills of
9:16middle age rapidly, but
9:18no, I
9:20I'm so fortunate in what I do
9:22to have found it or for it to have found
9:25me. You know, if I won all of the money
9:27in the world tomorrow,
9:30I would genuinely genuinely not do
9:33anything different. Um,
9:36I am so fortunate Well, I probably start
9:39trying to fly like business class or
9:41first class. That would be nice. But
9:42other than that, um, I would do nothing
9:44different. And I
9:46I'm very mindful of that because that
9:48sounds very privileged. And I know a lot
9:50of people
9:53endure what they do for a living rather
9:56than enjoy what they do for a living.
9:59And I know how lucky I am. So, I don't
10:02mean to be dismissive of of people in
10:04that God, I just know how much I love
10:06what I do.
10:07You you asked a question now which is,
10:08um, you you you posed a question which
10:11many people have tried to answer. You
10:12gave the the answer from 30 years ago
10:14about, you know, why do we sleep? Um,
10:17and it dawned on me as you said that
10:20that I've never asked myself that
10:21question.
10:22I've never even pondered the thought of
10:24why I sleep. I mean, I know what happens
10:26when I sleep. But do I know why my body
10:29can't just find another way? Why can't
10:31my body stay awake for the 24 hours? I
10:33know some animals, they sleep half their
10:34brain and then the other half kind of
10:36has a nap and whatever. Why why why do
10:39we sleep?
10:40It it's a puzzling question because when
10:42you think about it from an evolutionary
10:44perspective, it makes no sense
10:47whatsoever.
10:48Sleep is utterly
10:51idiotic because when you're sleeping,
10:54firstly, you're not finding a mate,
10:56you're not reproducing, you're not
10:58foraging for food, you're not caring for
11:01your young. And worst of all, you're
11:03vulnerable to predation.
11:06Now, on any one of those grounds, but
11:08especially all of them as a collective,
11:10sleep should have been strongly selected
11:12against during the course of evolution.
11:16But from best we can tell, sleep evolved
11:19with life itself on this planet.
11:22And it has fought its way through
11:24heroically every step along the
11:27evolutionary path.
11:29And what that has told us is that sleep
11:31must be essential at the most basic of
11:34biological levels.
11:36And now we understand that Mother Nature
11:39didn't make a spectacular blunder with
11:41this thing called sleep. Sleep, for
11:43example, will restock the weaponry in
11:46your immune arsenal.
11:48And it will make you a more
11:50immune-sensitive individual. So, you're
11:52more immune-robust
11:54when you wake up.
11:55We also know that it regulates your
11:57blood sugar levels. It controls your
12:00appetite hormones. It also regulates
12:02your sex hormones, testosterone,
12:04estrogen.
12:06Um sleep upstairs within the brain will
12:08fixate memories and help you learn and
12:11remember. Sleep will de-escalate
12:13anxiety. It will reduce your emotional
12:16difficulties and traumas. Sleep will
12:19actually cleanse away the Alzheimer's
12:22toxic proteins that build up in the
12:24brain. You know, the list is endless.
12:26These are all of the reasons that we
12:29need to sleep.
12:31But why can't I just do what those
12:34animals do where they half of their
12:35brain falls asleep and the half of the
12:37brain stays awake? Is that at all linked
12:39to the fact that we we live in tribes?
12:40So, we are essentially, although we're,
12:43you know, there might be 10 people in
12:44the tribe, we're
12:46all 10% of the tribe. So, we can rest at
12:48different times and kind of cover each
12:49other's backs or
12:51Gosh, yeah. So, actually, there are two
12:53nested
12:55very insightful questions there. The
12:57first is this notion of what you're
12:59describing with just what we call
13:00unihemispheric
13:02sleep, which is just a fancy way of
13:04saying you can sleep with one half of
13:06your brain and the other half is wide
13:07awake. Now, there are only a few species
13:10that can do this. Um for example,
13:12aquatic mammals, dolphins are great
13:15example. We can place actually
13:17electrodes on their heads and you can
13:20see that one half of their brain will be
13:22fast asleep. It will be in deep, deep
13:25non-REM sleep. The other half of the
13:27brain will be frenetic, wide awake.
13:30And in part for them, the reason is
13:33because they need to maintain aquatic
13:35mobility. You know, they need to keep
13:37surfacing for air, otherwise, you know,
13:39that's not going to be a good outcome.
13:41We also know that
13:43uh
13:44birds or even many avian species will
13:46have unihemispheric sleep. And you can
13:50actually see this. There's some great
13:51YouTube videos online where they will
13:53film one half of the sort of the side of
13:56the the bird's face and the eye is
13:59closed. And what it means is that the
14:01other half of the brain, cuz the brain
14:03is actually the left half controls the
14:05right side, the right side controls the
14:06left side. So, that left side is now
14:09fast asleep, which is the right eye
14:10closed. And then you kind of pan around,
14:13and all of a sudden, the other eye is
14:15wide awake, and it's clearly looking
14:17about. Now, this is obviously not for
14:19aquatic surfacing to gain air. This is
14:21for a different reason. What happens is
14:23that in a flock, a bunch of birds will
14:27all land on a branch.
14:29Now, all of the folks in the middle,
14:32they get to sleep with both halves of
14:33their brain. They can sleep with both
14:35halves or just one half.
14:37All of the folks in the middle, they get
14:38to sleep with both halves. The
14:40unfortunate girl or guy who sort of
14:43lands at the end, the far end,
14:46they will actually sleep with one half
14:48of their brain. So, one half of the
14:50flock, the entire flock, has one eye,
14:53180° of sort of half panoramic view
14:58uh out. The other bird on the other end
15:00will have the other half of the brain
15:02asleep with the other eye awake, giving
15:05the other 180° view of protection uh
15:09vision. And therefore, the entire tribe
15:12has a 360°
15:15assessment. Now, you would think, in
15:17fairness, that once those guys or girls
15:20at the end have done their duty, they
15:22get to move into the middle and they get
15:24to sleep with both halves. No, that's
15:26not what happens. What they will do
15:28after a while is that they will stand
15:29up, they will turn around 180 degrees,
15:33sit back down, and switch the other
15:35sides of the brain.
15:37Wow.
15:37So,
15:38to to just be clear, the complexity
15:42of wiring and architecture that has to
15:45happen for one half of the brain to be
15:48deep in sleep and the other half to be
15:50wide awake is astronomically hard. I
15:53mean, it's incredibly difficult to
15:55create that wiring.
15:56What that tells me is that if sleep was
15:59dispensable, if it was negotiable,
16:03then Mother Nature would have just found
16:04a different way for us to get all of
16:06these brain and body benefits and not
16:08gone to all of the evolutionary trouble
16:11of figuring out this fancy wiring for
16:13half-brain sleep. In other words, you
16:16just can't get away from sleep. You have
16:18to sleep. But, your second question, I
16:21think, is is even more fascinating,
16:23which is as as a tribe, because we are a
16:26tribe species.
16:29Now, there is something else that we
16:30call your chronotype.
16:32Are you a morning type, evening type, or
16:34somewhere in between?
16:37And by the way, you don't get to decide.
16:39It's not your choice. You know, this
16:41notion of these go-getter type A's who
16:44say everyone has to be awake at 5:00 in
16:46the morning, you know, you
16:48go to the gym, you blast out a workout
16:50for an hour, and you're at the desk by
16:526:00 a.m.
16:54Um
16:55you have no choice. If you're an evening
16:57type, you're an evening type. It's
16:58hard-coded. We know that right now
17:00there's at least 22 different genes that
17:02dictate what you are, morning type,
17:04evening type, or somewhere in between.
17:06It's about a third-third split across
17:08the population.
17:09Why is it a split? Why are we nicely
17:12spread out across our chronotypes? For
17:15exactly the reason you described.
17:17Because when we're in a tribe, if we all
17:19sleep at the same time, we're all
17:21vulnerable for 8 hours.
17:24But if you were to insert some genetic
17:26variability into when people have a
17:28desire to sleep, you've got the morning
17:31types who maybe go to bed at 9:00 p.m.
17:34and are waking up, let's say, at 5:00
17:36a.m. And then you've got all of the
17:38extreme evening types who are going to
17:40bed at 2:00 a.m.
17:42and waking up at maybe 11:00 or midday.
17:45So that way, the everyone gets their 8
17:48hours of sleep, but the entire tribe,
17:51the nucleus of this group of Homo
17:53sapiens themselves, is only vulnerable
17:57for maybe just 2 or 3 hours. So it's a
17:59clever solution that Mother Nature has
18:02come up with to say, "Everyone gets
18:04their 8 hours, but as a species, you're
18:07only going to be vulnerable for 2 to 3
18:09hours max when everyone at least as a
18:11collective is sleeping."
18:13Absolute genius.
18:14I used to think it was a load of
18:15nonsense, this this chronotype thing. Um
18:17it was actually on this podcast where I
18:19learned about its existence, and then I
18:20went on YouTube to learn more, and your
18:22video came up of you explaining it.
18:24Because I thought I always pondered why
18:26my partner
18:28goes to bed super early,
18:29wakes up super early. I go to bed late,
18:32wake up late.
18:34Um
18:35I'm going to ask you this question
18:36actually cuz it cuz I've I've wondered
18:37this. In that situation where I'm
18:39sleeping in bed with a partner that has
18:40a different chronotype,
18:41Yeah.
18:43it can have an impact on my sleep,
18:45right? Because of the way that the our
18:47sleep cycles work, and the REM sleep,
18:48and the stage one, deep sleep, etc.,
18:49etc. If she's woken up when I'm pulling
18:52into REM sleep, I if she's woken up at
18:545:00 a.m., but at 5:00 a.m. because I've
18:56gone to bed late, my REM sleep has just
18:58begun.
18:59That has quite a significant impact on
19:01me, right?
19:02If she is waking you up,
19:04Yeah, if she's wake if she wakes me up,
19:05then it's non-trivial. And likewise, if
19:08you're waking her up as you're getting
19:10into bed on the front end of sleep.
19:13So, it's very difficult one of the
19:15things that couples will cite if they
19:18break up. Firstly, is
19:20usually about a third of them will cite
19:22sleep difficulties or sleep issues as a
19:25as a cause of the the breakup or at
19:28least as a contributing factor to that
19:30breakup.
19:311/3?
19:31Yeah.
19:32Jeez.
19:32That it's one of at least one of the
19:34factors.
19:35When you go with then in and when you
19:37double click to say, "Okay, then what is
19:39it about this sleep kind of tension
19:42between the two of you?"
19:44One of those things is a mismatch in
19:46chronotype.
19:48And you can see this when, you know,
19:50people I think this, you know, on dating
19:52profiles now someone was telling me
19:53people will even say like, "I'm a
19:55morning type or I'm an evening type." As
19:57if you're stating up front this is part
19:59of my identity and just FYI be
20:01forewarned because maybe it's been an
20:03issue for them in the past.
20:05This is why I often speak about
20:09the notion of what's called a sleep
20:11divorce to prevent a real one.
20:14Now, it's not for everyone. Um a sleep
20:17divorce is where you sleep in separate
20:19locations.
20:20And when we've surveyed people um both
20:23uh you in the from the sleep council in
20:25the United Kingdom and also in the
20:27National Sleep Foundation here in
20:28America,
20:30the data is about the same. One in four
20:32people will say that they sleep in
20:34different locations with their partner.
20:37So,
20:38almost a quarter of
20:40people in relationships will sleep in
20:42different locations. We think it's
20:44potentially an underestimate because if
20:46you survey people anonymously,
20:49then a third of them will report waking
20:52up at least in a different location the
20:55next morning.
20:57And part of the reason that it's a taboo
21:00is because people think, "Well, if I'm
21:02if we're not sleeping together, then
21:04we're not sleeping together." The exact
21:07opposite is true that when a couple is
21:09sleeping well,
21:11we know that the sex hormones are
21:13improved, testosterone men, estrogen, um
21:16and uh
21:18uh luteinizing hormone in women. We also
21:20know that your
21:22um desire to be intimate with your
21:25partner is increased. Uh what we found
21:27is that for an hour of extra sleep, if a
21:30woman gets an hour of extra sleep, her
21:33libido desire to be intimate with her
21:35partner increases by 14%.
21:38Now, to give you some context, the FDA
21:41drugs for improving or increasing libido
21:44in women, drugs such as Vyleesi here,
21:47clinical drugs, they will increase it by
21:49about 24% and that's a pharmacological
21:52agent. But here, just the added
21:54non-pharmacological benefit of 1 hour of
21:57extra sleep will get you more than 50%
21:59of the way there.
22:01So, I want to just remove that notion of
22:04the stigma
22:05of that if you're not sleeping together,
22:08you're not sleeping It's usually quite
22:10quite the opposite.
22:12Um I would say that
22:15part of the the challenge, though, is
22:19that
22:21if we look at all objective measures, if
22:23I measure your sleep and the sleep of
22:26your wife,
22:27if when you're sleeping separately
22:29versus when you're sleeping together,
22:31it's very likely that objectively you
22:33will both be sleeping worse when you're
22:35sleeping together. That's what the
22:36science tells us. However, what's
22:39interesting is that when you survey
22:41people and say, "How satisfied are you
22:44with your sleep?" which is a subjective
22:46measure, people will say, "I'm actually
22:49more satisfied with my sleep when I'm
22:50with my partner than when I'm sleeping
22:54alone." So, there's a mismatch here.
22:56Objectively, your sleep is better, but
22:58subjectively, you still prefer that. And
23:01of course, it's natural. you know, we
23:03there is safety, there's security in
23:05co-sleeping, there is this
23:08sort of connection that we get.
23:11You You can approach it if you want.
23:13Just be honest with yourself.
23:15And be honest with your partner.
23:18And you can start by saying, "Look, this
23:20isn't forever.
23:22I just want to say let's do an
23:24experiment for a week, 10 days. Let's
23:27Let's just try it and see how it goes.
23:30It doesn't need to be permanent."
23:31Because what you actually miss
23:34are the bookends of sleep.
23:36For the most part, the two of you are
23:38not conscious for most of the experience
23:40of sleeping together.
23:42It's really getting into bed and sort of
23:43having a kiss or a cuddle or and sort of
23:46waking up together in the morning and
23:47sort of
23:48Now, obviously, when you're a mismatched
23:50chronotype, that's also can be a
23:51challenge, too. So, you can still have a
23:54sleep divorce, but you can set up a a
23:57system where you will go in, you'll say
23:59your good nights, and you'll kind of get
24:01into bed, have a kiss and cuddle, and
24:02then you retreat to a separate location.
24:05And you can repeat that same process. Um
24:07so,
24:09I I don't want to sort of
24:11belabor the point of a of a sleep
24:13divorce, but um people can certainly
24:15explore There is something called a
24:17halfway house, which is called the
24:19Scandinavian method, which sounds far
24:21more salacious than it actually is. It's
24:24simply that you buy two beds, and you
24:26put them side by side in the same room,
24:29and therefore, the amount of disruption,
24:31physical um disruption that happens by
24:34way of sheets and movement, is
24:36decreased.
24:37But that doesn't solve it all. Sometimes
24:39there is snoring, uh sometimes there is
24:41sleep talking. Those things are not
24:43obviated by the Scandinavian method.
24:46When you think about where society is, I
24:48was I was I was going to ask you, you
24:49know, you said you wanted to to do the
24:51work you're doing now for the rest of
24:52your life.
24:53Um so, do you think the work you're
24:54doing now is going to become
24:56increasingly more important and
24:58relevant.
25:00I mean, is the problem going to get
25:01worse?
25:02Mhm.
25:02Or is it going to become less
25:04significant and less relevant? Based on
25:06the trajectory of societies, do you see
25:08it?
25:10You know, I'm
25:12mixed. I think when I wrote the book, I
25:14started writing uh
25:17the a book that was called Why We Sleep
25:19back in probably about 2014 or 15, and
25:22at that point sleep was the neglected
25:24stepsister in the health conversation of
25:27that day. You know, we were speaking a
25:29lot about diet and exercise, which was
25:30wonderful, but there was no voice of
25:33sleep.
25:35And I was so sad about that because I
25:36could see so much disease and suffering
25:38that was coming so clearly by way of a
25:41lack of sleep, but it wasn't there on
25:45the public buffet menu for consumption
25:48of knowledge.
25:49And so, that was part of the motivation
25:52for trying to write the book. So, I
25:55would say now,
25:56and this is not because of me or the
25:58book or anything like that, but is is
26:00sleep more of a conversation in this day
26:03and age than it was six or seven years
26:06ago. I think I would say yes, there is a
26:09greater awareness of of sleep.
26:12Um
26:14but
26:16with that awareness,
26:19I want I think one can still question
26:22the pragmatics, meaning
26:24just because we're talking about it more
26:26does not mean that people are still
26:29failing to either get the sleep that
26:32they need or that they are unable to get
26:36the sleep that they need. And those two
26:37things are different. One is that you
26:39are healthy and you can generate the
26:41sleep that you need, but you don't give
26:42yourself the opportunity, time, or life,
26:44I should say sometimes, cuz it's
26:46sometimes not your choice. Life does not
26:48give you the chance to get sleep. And if
26:49only you had the chance, you could
26:51sleep. That's one version. The second
26:53version is, "No, I'm giving myself the
26:55right opportunity to sleep, but because
26:58I'm anxious or because of other issues,
27:01I am not able to generate sleep. I
27:02suffer from insomnia and sleep
27:04problems."
27:05So, those two things I don't see having
27:09changed since
27:12you know, I think this public movement,
27:14this increasing movement of sleep
27:16conversation came on the table. So, in
27:18that regard, I'm more pessimistic than I
27:21am optimistic. And I think it will only
27:24get worse. If you look at rates of
27:26insomnia, for example, they're only
27:28increasing. They're only escalating.
27:30Rates of anxiety disorders, the very
27:32same thing. And those two things are
27:34intimately intertwined.
27:37So, I think
27:39I wish I my mission was extinguished
27:42within the next couple of years, because
27:44society started sleeping wonderfully
27:46well. I don't think that's going to be
27:48the case. So, I think I've got my work
27:50cut out for me
27:51um to try and help people with better
27:53sleep. Um
27:55Is it So, it's getting We're getting
27:57worse at sleeping?
27:59I think
28:00modernity is making it
28:04so much more difficult for us to sleep.
28:06Modernity? What's that?
28:08I think it when you think about
28:11you know, we often think about sleep as
28:12a biological process, and it very much
28:14is.
28:15And but
28:17also, it's so environmental as well as
28:21biological, meaning
28:24when you were to say, you know, "How did
28:26you sleep last night?" Think about all
28:28of the external factors that changed it.
28:31Well, I had to be up at this time. I had
28:33to catch a flight this time. My partner
28:35went to bed at this time, and she woke
28:37up at this time. There was this noise
28:39that sort of happened. I'm now sleeping
28:41in a hotel room." You know, there are
28:43countless externalities.
28:45And those externalities are shaped by
28:48this thing called the modern world. And
28:50in the modern world, if I could really
28:52be cynical, and I'm not someone, I'm
28:54very optimistic and I'm very
28:56non-cynical, but you could argue from a
28:58capitalistic standpoint that society
29:01does not want you sleeping.
29:03Because what society wants from a
29:05capitalistic point of view is that
29:07you're either producing
29:09or you're consuming.
29:10And when you're sleeping, you're neither
29:12producing and you're neither consuming.
29:15And so,
29:17there are lots of ways that I think
29:19society and the modern world has
29:22conspired,
29:23willfully or not, conspiratorially or
29:27not, to
29:31decrease and try to diminish sleep. In
29:33fact, I think the CEO of Netflix several
29:37years ago, and I'm sure that YouTube
29:39comments will correct me if I'm wrong
29:40here, but I believe his very statement
29:42was that we are
29:44we are deciding to commit war against
29:47sleep.
29:48That was their goal.
29:50And it just stunned me that, you know,
29:53that we're going to go to war with
29:55sleep. We're going to remove you from
29:57your sleep. So, there are lots of ways
29:59in in which I think society does not
30:01help us. Light is another good example.
30:04We are a dark-deprived society in this
30:06modern era because we're exposed to
30:08light. We are not giving ourselves the
30:11right temperature cues. You know, we go
30:13into an office where it's you know, 20°
30:17or 70° C, whatever it is, stock-stable.
30:20Then we come home and we regulate our
30:22temperature at home to be the same
30:24thing.
30:25We take on board probably too much
30:27caffeine in this day and age, although I
30:29am actually an advocate of drinking
30:31coffee and I can explain why, too.
30:34But anxiety, as I said, is a huge issue.
30:38All of these things are preventing and
30:41classic roadblocks to sleep.
30:45How many of us are getting the sort of
30:47recommended daily allowance of sleep as
30:50a percentage, do you know?
30:51It seems to be about
30:541/3 of
30:56most modern civilizations
30:59are failing to get the recommended 7 to
31:019 hours of sleep a night.
31:031/3 so roughly 30 35% 33% roughly.
31:07Yeah.
31:08And does that have geographic variants?
31:10I in some countries it's worse and some
31:12countries it's better. I'm thinking
31:13about the UK versus the US or you know,
31:15Japan or whatever.
31:16Yeah, it is. And in fact, you let me
31:19give numbers to the three countries that
31:21you described. Here in the United
31:24States, the average amount of sleep that
31:27people are getting is 6 hours and 29
31:32minutes. In the UK, it's not much
31:33better, 6 hours and 49 minutes. Japan
31:37was the worst, 6 hours and 22 minutes.
31:41Now, to be clear,
31:44that's the average.
31:46What that means is that there is still a
31:48large proportion of that bell-shaped
31:50distribution
31:52of people getting even less than that
31:55amount.
31:57Now, there are some countries that you
31:59look at that are actually sleeping much
32:02better than that. I think let me
32:05Mexico for example is is doing very
32:09well. If you look at Mexico City,
32:10people are actually sleeping not too far
32:13off from 8 hours. So, there is
32:15variability and we can try to understand
32:17why, which by the way just brings me
32:20back while I think about it to your
32:21comment of will my work be done not from
32:24the because I'm a scientist and I do I
32:26have a run a big sleep center at UC
32:28Berkeley, but the work I do as a
32:31hopefully a public advocate for sleep
32:33why I don't think it's going to change
32:35um,
32:36soon
32:37is because
32:38governments aren't really doing much
32:41about it and I've tried as best I can
32:43and if there is any government out there
32:45that listens to this that wants to work
32:46with me, I'd be delighted.
32:49I don't remember and maybe you can, but
32:52any major first world nation government
32:55that has had a public health campaign
32:57regarding sleep.
32:59And it stuns me because those same
33:02governments have had public health
33:04campaigns regarding, you know, eating,
33:07regarding smoking, regarding drunk
33:09driving, regarding risky behaviors, safe
33:12sex,
33:13loneliness,
33:14loneliness, mental health,
33:17suicide.
33:19Where is sleep in that equation?
33:23And it's such a fundamental ingredient.
33:26And in fact, almost all of those things
33:28that I've just described
33:30have an intimate relationship
33:33with sleep. I mean, suicide especially.
33:35We were starting to do a lot of work
33:37with this, although it's been hard to
33:38get funding. But what we found is that
33:41insufficient sleep is a precursor to
33:44suicide. That sleep disruption seems to
33:47predict both suicide ideation, in other
33:50words, suicidal thinking, suicide
33:53planning, and tragically, suicide
33:56completion as well.
33:58So, if we were to try to have
33:59governments create a public health
34:01campaign to pull this Archimedes lever
34:05on better sleep, there are so many other
34:07health benefits. You know, sleep is the
34:10tide that rises all the other health
34:12boats. It's almost like a
34:15it's like a mixing deck in a studio. You
34:17know, in those sound studios where
34:18you've seen it. And then there's that
34:19one button all the way to the end, the
34:21white button, sort of that when you move
34:23it up, sort of all of the other dials,
34:25the sort of the red, yellow, orange,
34:27green dials, they all move up at the
34:29same time as well. There's this like
34:30sort of one messed like one ring to rule
34:33them all. Sleep is that
34:35Archimedes lever. So, if governments
34:37could only execute on that, the health
34:40benefits would be manifold in terms of
34:43their consequences.
34:44It begs the question, you know, if I
34:46were to make you today
34:48president, prime minister, whatever, of
34:50the world,
34:51and you had to do, you know, just a few
34:53things to really fix the
34:57lack of sleep epidemic, there you go,
35:00diagnosed it. Um what would those things
35:02be if you were in charge? How would you
35:04redesign society to help us to sleep
35:06better?
35:09Gosh, it's such a good question and I've
35:11thought a lot about this
35:13it almost in reverse, which is to say
35:16why is it that we are struggling to get
35:19sleep? And there is no single answer.
35:21There are so many different reasons, and
35:23that's why it's actually a very
35:25challenging problem to solve.
35:28I would go through a descending level of
35:30steps. So, first I would start at the
35:32government level, and we would get those
35:34public health campaigns in order.
35:37Um next, I would go to the professional
35:40level, because there we have this
35:42mentality in business that, you know,
35:45sleep is for the soft among us, that
35:50less sleep equals more productivity.
35:54And that is just not true, and I can
35:56provide you with all of the evidence.
35:58So, we need to get rid of this sort of
36:00sleep machismo attitude in the
36:02workplace, where we wear wear our badge
36:04of honor of sleep deprivation on our
36:06arms. We need to get companies to
36:08actually start embracing sleep. And I
36:10can guarantee you, and I can give you
36:12all of the evidence as to why, if as a
36:15company, as a CEO, if you start
36:18prioritizing the sleep of your
36:20employees, you will be far better off as
36:23a company. You will be more
36:25product-based, and you will be more
36:27profitable and revenue generating.
36:30Sleep is the very best form of
36:32physiologically injected venture capital
36:34that you could ever wish for. And in
36:36fact, the RAND Corporation, which is an
36:38independent survey corporation, what
36:40they found is that at a national level,
36:43insufficient sleep costs most nations
36:46about 2% of their GDP.
36:49So, here in America, that number was
36:50$411 billion
36:53of lost profit caused by insufficient
36:55sleep. In the United Kingdom, it was
36:57over $50 billion.
36:58In Japan, it was over $120 billion.
37:01If I could solve the sleep loss crisis
37:03in the workplace, I could perhaps double
37:06the health care benefit for many of
37:07those countries, or I could halve the
37:09out the education deficit in those
37:11countries. So, the next level I would
37:13target is
37:14at business. Then next step down would
37:16be medicine.
37:18Medicine is a classic demonstration
37:20here. We have junior doctors, or here in
37:22America, they have doctor residency
37:25programs, where people are working 20-30
37:28hour shifts.
37:30And so, already doctors are inculcated
37:33into the mindset of the uselessness
37:36of of sufficient sleep.
37:39Across numerous countries, and I think
37:41it was maybe over eight different
37:43countries, we looked at the medical
37:45curriculum.
37:46And we asked, "How many hours of
37:47education do doctors get about sleep?"
37:51And what's strange is that, you know,
37:52often doctors will you go in and you'll
37:53have an appointment, they'll say, "Okay,
37:54you know, how you eating?" And you know,
37:56what's going on with the bathroom? How's
37:58the toilet? Um and then, you know, how
38:00are you sleeping?" As if sleep is one of
38:02these universal health barometers. But
38:04what we found is that most doctors will
38:06only be given about an hour to an hour
38:09and a half of sleep education during
38:11their entire medical school education.
38:15Which
38:16blows my mind because it is 1/3 of their
38:19patients' lives, but they're only given
38:23about 90 minutes of education. So, no
38:25wonder your doctors aren't treating your
38:28sleep problems, thinking about your
38:29sleep problems, understanding your sleep
38:31It's not their fault. And plus, they're
38:33sleep deprived anyway when they're being
38:35trained.
38:36Ironically, by the way,
38:39doctors, junior doctors who've worked a
38:4130-hour shift, when they finish that
38:4430-hour shift and get back in their car,
38:46they are 168%
38:48more likely to get into a car accident
38:51because of their lack of sleep and end
38:53back up in the emergency room from where
38:55they were just working, but now as a
38:57patient. I mean,
38:59this the paradox,
39:01the irony just stuns me. So, I next
39:03moved down to the level of medicine.
39:05Then, I would go to education
39:08because we don't get taught about sleep
39:10in schools. Now, I never got one of
39:13those special classes. You know, I got
39:15sort of, you know, sexual education
39:17classes, classes about drugs. No one
39:20came in and told me about the benefits
39:22of sleep. Why aren't we doing that? Then
39:25next, I would move down into the family
39:28because there is prejudice in families
39:30with sleep. It's this notion of
39:33parents of teenagers. And these
39:36teenagers, by the way, it's not their
39:38fault. They have a shift in their
39:40chronotype, in their circadian rhythm,
39:42that when they go through puberty, when
39:44they're going through adolescence, they
39:46get fast-forwarded in time. So, when
39:48they were 8 or 9 years old, they would
39:50be going to bed, you know, sort of early
39:53in the evening, but now as teenagers,
39:55they seem to be stubborn and they're
39:57staying awake, staying awake until
40:00midnight, 1:00 a.m., and they won't get
40:03into bed. It is not their fault because
40:06they have a biologically wired shift in
40:10the tendency of when they want to wake
40:12up and when they want to sleep. Why am I
40:14bringing this up about this sort of
40:16mismanagement in the home because
40:18parents weekends they'll go into the
40:21room of the teenagers they'll, you know,
40:22pull open the the curtains they will
40:24pull the covers off and they say you're
40:26wasting the day.
40:28You know, and firstly what they're doing
40:30is probably trying to sleep off a debt
40:33that we've lumbered them with during the
40:35week because of this incessant model of
40:37early school start times which I'll I'll
40:39come back to.
40:41But within the home if you ask parents
40:44of teenagers what percent of parents
40:47think that their teenagers are getting
40:49sufficient sleep and about 70% of them
40:51will say yes, my teenager is getting
40:53sufficient sleep. When you look at the
40:55data only about 15% of teenagers are
40:58actually getting the sleep that they
40:59need. So what happens is a parent-child
41:03transmission of sleep neglect.
41:05They're saying you're lazy, you're
41:06slothful. So then what happens? Well, in
41:1015-20 years time now that teenager has
41:14got a teenage child, what do they do?
41:17They go back in the room, they rip the
41:19curtains open and they say you're
41:19wasting the day because that's what they
41:21were told. So we need to break that down
41:24too and then finally we need to come to
41:26the individual and we need to solve the
41:28individuals sleep problem. So it's a
41:30very long answer and I'm desperately
41:32sorry to a very big question as to what
41:34I would do if I was off for a day but I
41:36hope that gives you some
41:39sense of of the depth that I think we
41:42need to go to. I've tried to think about
41:43the question a lot. It's not
41:45particularly well executed. I don't
41:46think I was very eloquent there but I
41:48hope that gives a sense.
41:49It sounded perfectly eloquent to me. It
41:51sounded like a manifesto so
41:53um hopefully if there are people
41:54listening from governments which I'm
41:55sure there are cuz, you know,
41:57I hear about that sometimes which is
41:58quite bizarre but um I
42:00I'm sure they'll be getting in touch
42:01with you very quickly. Going back to the
42:03top of that that stack on the company
42:06level. So as a CEO or a CFO or an
42:08employer whatever, um there are some
42:11companies that are incentivizing their
42:13team members to sleep, right? Is there
42:14any data showing the efficacy of that?
42:17There is data that we have, and it's
42:21bidirectional, both the efficacy of when
42:24you
42:25increase sleep, and also the detriment
42:28when you don't allow sleep. So, a great
42:31example was, um,
42:33NASA back in the 1980s,
42:38they were looking at using naps in the
42:42astronaut program, because when you're
42:45up and you're orbiting Earth, you will
42:47actually be cycling Earth, you know,
42:50really quite quickly, and you will get
42:52to see, depending on the orbit, maybe
42:55somewhere between 10 to 15 sunrises
42:58every 24 hours, which sounds, I mean,
43:01amazing and remarkable, but trust me, in
43:03terms of your sleep, it is very
43:06dislocating.
43:08So, they were looking at how to use naps
43:11strategically to improve performance,
43:13because the weakest link on any space
43:16mission, and we've done some work with
43:17NASA, um,
43:19is the human being themselves. And they
43:22can cause catastrophic failure. Now, if
43:24you make an error at work, and you're
43:26here terrestrially on the ground, you
43:28know, it's probably non-trivial.
43:30You make an error when you're up in
43:32space,
43:33it can be a big deal. So, they were
43:35looking at that. And what they found was
43:37that these naps, anywhere between 20
43:40minutes to an hour, could increase
43:44productivity
43:45on these different tasks by about 34%
43:48and increase general alertness by over
43:5050%, and in fact, the data was so
43:53powerful that it ended up being
43:55transmitted to all of the terrestrial
43:57workers on the ground that NASA would
43:59start to It was what was called NASA
44:01naps. It was a NASA nap culture. Now,
44:04NASA isn't desperately compassionate by
44:07any means. It's a great organization.
44:09But they, just like companies like
44:11Google or Facebook, they understand the
44:14pounds and pennies sense, you know, the
44:17dollars and the cents
44:18version of productivity.
44:20So anything that returns productivity,
44:23they will invest in. And some of those
44:24companies, you know, I um
44:26I did some work at Google during a
44:29sabbatical. And there on their campus,
44:31they will have these nap pods and they
44:33will have these what are called shh
44:35rooms where you can go and you can take
44:38a nap.
44:39So think about 20 years ago, you would
44:42never imagine a company paying you to
44:46sleep on the job. If you were caught
44:47sleeping on the job, you'd probably be
44:49fired. Now companies are incentivizing
44:51it. Not because they are thinking
44:54compassionately or empathetically about
44:56the health or the wellness of their
44:58individuals. It is because they
44:59understand that it transacts marked
45:01productivity. So NASA was a good
45:03example. When you give sleep, you get
45:05something back. But I can go back to the
45:07reverse of that.
45:09Why we think that a lack of sleep does
45:12not equal more productivity is for at
45:14least five reasons. First, when you
45:16survey, and we've we can do these
45:18studies in the in the laboratory, too.
45:20When you undersleep employees, they will
45:23choose less challenging problems. So if
45:26you give them an array of work problems,
45:28they will just simply, you know, check
45:30email, they'll listen to phone messages.
45:32They don't dig into deep project work.
45:34Second, of the problems that they do
45:37take on in their work, they will produce
45:40fewer creative solutions.
45:42And after all, creativity and ingenuity
45:45are supposed to be the two engines that
45:47drive businesses forward in terms of
45:50their productivity and their revenue.
45:53The third that interesting finding that
45:55we've discovered is that when underslept
45:57employees start working in teams,
46:00they will slack off. They won't do their
46:03work. They will let other people do
46:04their work. It's what we call social
46:06loafing. So, they ride the coattails of
46:08other people's hard work, which won't
46:11breed a good atmosphere in your company.
46:13You know, trust me.
46:15The fourth thing that we found is that
46:17underslept employees are more deviant.
46:20That they're more likely to fudge data
46:22in spreadsheets. They're more likely to
46:24falsely claim uh money for reimbursement
46:27that was inappropriate.
46:30The final thing is that a lack of sleep
46:31will go all the way to the top of the
46:33business chain. What we found is that
46:36the more or less sleep that a business
46:38leader has had from one night to the
46:40next to the next, the more or less
46:43charismatic that employees will rate
46:46that business leader from one day to the
46:49next to the next, even though the
46:51employees themselves, they know nothing
46:54about the sleep that that CEO has been
46:56getting. It's evidential in how
46:59charismatic that CEO is.
47:02So, you can add all of these things up
47:04and no wonder you
47:07if you don't snooze, you lose in the
47:09case of business in that regard. That's
47:11why I can produce, I think, a
47:13non-trivial case for business. By the
47:15way, the other aspect that is hugely
47:18costly to businesses and when I go and
47:20speak to businesses about why they
47:22should value sleep,
47:25if you offer it on the grounds of again
47:27sort of compassion or mental health,
47:31they probably don't want to listen. When
47:32you convert it into the cost to the
47:33company and how much it's fleecing them
47:36in terms of their prof- profits, then
47:38they start to pay attention.
47:40Underslept employees will
47:43take on average about 11 more days
47:47uh sick days throughout the year
47:49relative to well-slept individuals. So,
47:51you're essentially just paying people
47:53additionally for 11 days of work that
47:55they will never give you when you are
47:57under sleeping them. Secondly, the
47:59utilization of health care resources
48:02increases by about 80%.
48:05So, the cost to either you, the company
48:07here in the US where your company is
48:09paying for your health care, or the cost
48:11to the government, for example, in the
48:12United Kingdom is astronomical.
48:16And also then the co- what we call
48:19comorbid diseases, your rates of
48:21obesity, diabetes, cardiovascular
48:24disease, mental health conditions, all
48:26of these things escalate as under slept
48:29employees continue to get even more
48:31under slept.
48:33So, there is no strong case that I've
48:36seen
48:38that leads me to think
48:40businesses should foster the mentality
48:43of insufficient sleep. Quite the
48:45opposite. So, that's hopefully an answer
48:47to a question. We can look at it
48:48bi-directionally. When we give sleep
48:49back, do you get productivity? Yes. When
48:51you take sleep away, the things implode
48:53rapidly? Yes. And is it costly to your
48:56company? Very much so.
48:58On that point of naps, and you know,
49:00Google sleep pods, naps, and things like
49:02that. There was a point in my life where
49:04I because I learned about REM sleep and
49:07the importance of REM sleep and deep
49:08sleep, and that happens a little bit
49:10further on into my, you know, the
49:1290-minute Look at me trying to tell a
49:14sleep expert about this.
49:15No, I love it.
49:16But do you see what I mean? Like, this
49:17is my very This is my monkey brain. So,
49:19I didn't understand the subject matter
49:21very well. I still really don't, to be
49:22honest, but in the first It takes me a
49:25significant amount of time to get to
49:27deep sleep into REM sleep.
49:29How long on average would would you say
49:30it takes for it for some, you know,
49:32Yeah, so you will probably go into light
49:35sleep in the first 10 to 15 minutes.
49:36Then you'll go down into deep sleep.
49:38You'll stay there for about 30, 40
49:41minutes. Then you'll start to rise back
49:43up and you'll pop up and you'll have a
49:44short REM sleep period. And then you
49:47complete the non-REM to REM cycle after
49:50about 90 minutes, and back down you go
49:52again, down into non-REM, and up into
49:55REM. So, on average for human beings,
49:57it's 90 minutes.
49:58So, I therefore assumed that napping
50:01really does nothing, because I thought,
50:03well, it takes me so long to get to REM
50:04sleep and to deep sleep that there's If
50:07I've got 15 minutes, 20 minutes to to
50:09nap, it's just a waste of time.
50:11Right.
50:12Was I wrong, or was I right?
50:14You were
50:16understandably wrong.
50:18Okay, good.
50:20I'm happy because I I've always rejected
50:22naps because I thought they didn't
50:23matter, because it takes me so long to
50:25get to a restorative state anyway, so.
50:27So, we've done lots of different studies
50:29with naps, we and other colleagues, too.
50:32And what we found is that naps can
50:34transact some fantastic benefits. They
50:36can improve cardiovascular health, lower
50:38blood pressure.
50:40They can improve your learning and
50:42memory abilities.
50:44They can reset the emotional
50:48north of your magnetic compass in a good
50:50way, where you can de-escalate negative
50:53emotions and increase positive emotions.
50:56Um so,
50:57naps certainly are a good thing, but
51:00with a big caveat that I'll come back
51:02to.
51:03Um yes, you're right in the sense that
51:06to get a full cycle of sleep and to get
51:09into REM sleep, you would probably have
51:11to make that nap about 90 minutes. And
51:14in fact, a lot of the studies that we
51:16do, we will use a 90-minute nap duration
51:19of time so that the brain can cycle
51:22through all of those different stages of
51:24sleep.
51:25But you don't need to, nor would I
51:26suggest that you do.
51:29What we found is that different stages
51:30of sleep perform different functions for
51:33the brain at different times of night.
51:36There are actually four separate stages,
51:38stages one through four, increasing in
51:40their depth of sleep. So, stages three
51:42and four are those really deep stages of
51:45non-REM sleep. Stages one and two,
51:46that's the lighter form of non-REM.
51:49And then you have rapid eye movement
51:50sleep, or what we think of as dream
51:51sleep.
51:52And people will sometimes say to me,
51:54"How do I get more REM sleep? Or how do
51:56I get more deep sleep?" And my response
51:59to them is, "Why do you want to get more
52:01REM sleep?" And their answer is, "Well,
52:02isn't that the good stuff?"
52:05And it turns out that there is no good
52:07stuff. It's all good stuff. You know,
52:09maybe with the exception of that light
52:12stage one non-REM sleep, that's shallow
52:14sleep and we typically don't like to see
52:16too much of that. But stage two non-REM
52:18sleep, three and four, they all have
52:20their different functions that we've
52:22discovered. And REM sleep has its
52:23functions.
52:25So, you need all of them. You can't
52:26short short shortchange any of them. But
52:29for a nap,
52:31what we found is that you can get
52:33nice benefits for things like your
52:35learning and your memory, and it can
52:37even reduce some level of anxiety
52:40up to about 20 minutes. You can In fact,
52:43you can nap, I think the study one of
52:45the studies, they brought a nap down to
52:47about 9 minutes in duration, and there
52:49were still some basic improvements for
52:52your sort of general level of alertness
52:54and reaction time. For example, if
52:55you're an athlete, that's that's
52:57non-trivial.
52:58So, um
53:00so, the reason I would say
53:03be careful with naps is for two main
53:07um sort of suggestions. The first is,
53:09try not to nap for about longer than 20
53:11minutes, because once you go past 20
53:13minutes, you really start to go down
53:15into those deeper stages of non-REM
53:17sleep. And if you wake up after about 45
53:20minutes or 60 minutes,
53:23it's not a problem. I'm not suggesting
53:24that you shouldn't or you couldn't. I'm
53:27just saying be aware, because when you
53:28come out of that deep sleep and you wake
53:30up from that deep sleep, normally that's
53:32not how you wake up. You will usually
53:34wake up out of lighter stages of sleep
53:37or out of REM sleep. It's rare that we
53:39wake up out of deep sleep. But if you
53:40nap and you snap for about 40 minutes,
53:43you'll probably go down into deep sleep.
53:46And at that point, what if you wake up
53:48and your alarm goes off,
53:49then you're going to feel almost
53:51miserable and worse than you did before
53:53the nap, because you have what's called
53:55sleep inertia, which is essentially a
53:58sleep hangover,
53:59where the brain is still sort of pulled
54:02back into that deep sleep state, and it
54:05can take you almost an hour before you
54:07feel like you're back up to operating
54:09temperature and you're up to motorway
54:10speed.
54:12So, I would say keep it 20 minutes, and
54:14you don't suffer too much of that
54:15inertia. You still get some nice
54:18benefits.
54:19Also, don't nap too late in the
54:21afternoon.
54:22Also, the final part is if you are
54:25struggling with sleep at night, if
54:27you're someone who has insomnia or sleep
54:29difficulties, do not nap during the day.
54:33It's the worst thing that you can be
54:34doing.
54:35Because
54:36when we're awake during the day, we
54:38build up a sleepiness chemical in our
54:40brain. It's called adenosine.
54:43And the longer that we're awake, the
54:44more adenosine that builds up, the more
54:46adenosine that builds up, the sleepier
54:48and sleepier that we feel.
54:51And when we sleep, the brain gets the
54:52chance to clear away all of that
54:55adenosine, all of that sleepiness.
54:57And somewhere between 7 to 9 hours after
54:59sleeping a full night, the brain has
55:02evacuated all of that sleepiness
55:05chemical, all of that adenosine, so that
55:07then we should wake up and we should
55:09feel refreshed and restored and not
55:12needing caffeine to to function.
55:15Why is that relevant to naps? Well, it's
55:17relevant to naps because when you take a
55:19nap, you're essentially it's like a
55:21pressure valve on a cooker. Pshh, you're
55:24just releasing some of that healthy
55:26sleepiness that you've been building up.
55:28And therefore, if you are struggling
55:29with sleep at night, and then you nap
55:31during the day, it's terrible because
55:34you're taking away all of that healthy
55:36good weight of sleepiness that we've
55:39been trying to build up on your
55:40shoulders to give you the best chance of
55:43a good night of sleep.
55:45That's why I would say if you are
55:47suffering from insomnia, don't nap
55:48during the day. Also, even if you are if
55:51you don't struggle with sleep at night,
55:53try not to nap after about 3:00 p.m. in
55:56the afternoon or 2:00 p.m.
55:58Napping late in the afternoon or in the
56:00early evening, it's a little bit like
56:02snacking before your main meal. It just
56:05takes the appetite off your sleep
56:07hunger. So, try not to do that. But,
56:09naps, for the most part, if you don't
56:11struggle with sleep, they are wonderful
56:13things. Just keep in mind the 20-minute
56:15sort of idea.
56:16You mentioned caffeine there. A topic
56:18I've mulled over
56:20over and over again on this
56:21show.
56:22Um because as I've said to uh maybe
56:24three or four of my guests now,
56:27it feels like caffeine is a miracle drug
56:30that comes with no apparent cost. But,
56:32when I think about things like anxiety
56:34and I don't know, shallow sleep states.
56:36I've always pondered that maybe caffeine
56:38is playing a role in that. You said you
56:40you're you're pro-caffeine. You're a
56:41caffeine drinker yourself.
56:43So, I am not a caffeine drinker myself,
56:45but I am pro-coffee.
56:48Oh, okay.
56:48And I'm I'll tell you why I'm very
56:51thoughtful about my wording between
56:53caffeine and coffee there. And to your
56:56point, it's a it's another astute one,
56:58which is
57:00it would you know, is it a miracle drug
57:02with no cost?
57:05In biology and medicine, there is almost
57:08no free lunch.
57:11Um and
57:14that is true when it comes to caffeine
57:16and sleep. So,
57:18perhaps I'll give the skinny on caffeine
57:21and how it impacts your sleep, but then
57:23circle back around to what seems an
57:25oxymoronic statement for me, which is
57:27why I'm still pro-coffee.
57:30Um caffeine will hurt your sleep in
57:33probably at least
57:35three ways, some of which you most
57:38people are not aware of.
57:39The first issue is the duration of its
57:42action.
57:43So, caffeine has what we call a
57:45half-life of about 5 to 6 hours. In
57:48other words, after about 5 to 6 hours,
57:51half of that caffeine is still in your
57:53system.
57:54What that means is that caffeine has a
57:55quarter-life
57:57of somewhere between 10 to 12 hours.
58:00So, if you have a cup of coffee at noon,
58:02at midday,
58:04a quarter of that caffeine is still in
58:06your brain at midnight.
58:08So, having a cup of coffee at noon, and
58:11it's
58:12hyperbole in truth, probably or it's a
58:14little bit hyperbolic, but it's almost
58:16the equivalent of
58:18a coffee at noon is the equivalent of,
58:19you know, tucking yourself into bed and
58:21just before you turn the lights out, you
58:23swig a quarter of a cup of coffee and
58:25you hope for a good night's of sleep,
58:27and it's probably not going to happen.
58:29So, that's the first thing to keep in
58:30mind is the
58:31timing of of caffeine.
58:34The second is that caffeine is a
58:36stimulant. Now, everyone knows this.
58:38Everyone knows that caffeine can make
58:40you more alert and more awake. By the
58:42way, how does it do that? Um, it comes
58:44back to adenosine, which is the chemical
58:46that we spoke about, the sleepiness
58:48chemical.
58:49It's no coincidence that those two
58:50things sound the same at the end of the
58:52name, caffeine and adenosine.
58:55Caffeine will actually race into your
58:57brain and it will latch onto the
58:59adenosine receptors, the welcome sites
59:02in your brain. And it has very sharp
59:04elbows and it will force away the
59:06adenosine from those receptors and it
59:09will hijack those receptors.
59:11Now, at this point you may be thinking,
59:12well, hang on a second. If it's latching
59:14onto those sleepiness chemical
59:16receptors, shouldn't caffeine make you
59:19more sleepy? And the answer is no,
59:21because what it does is it just latches
59:23onto the receptor and it inactivates it,
59:26essentially. So, it masks the receptor.
59:30What caffeine does then is race into
59:33your brain. You've got all of this
59:35sleepiness at 9:00 p.m. or 10:00 p.m.
59:37You have an espresso cuz you're trying
59:39to power through and finish the report
59:41or, you know, the presentation for your
59:43sort of your pitch for your deck for
59:45your startup company.
59:47And that caffeine races in, it latches
59:49onto the adenosine receptors,
59:52and blocks the signal of adenosine. So,
59:55now your brain was thinking, "I'm
59:56starting to get tired. It's 10:00 p.m."
59:59But now, all of a sudden that signal is
1:00:01blocked.
1:00:02And it caffeine is like hitting the mute
1:00:05button on your television remote
1:00:07controller. It just muts the signal of
1:00:09sleepiness. So, now you think, "Well,
1:00:10now I don't feel sleepy anymore." And
1:00:13here's the danger
1:00:14that even though well, when the caffeine
1:00:16is in your system and it's latched onto
1:00:18the receptors, that adenosine is still
1:00:20there. It's not going away. In fact, if
1:00:23anything, during the course of the
1:00:25caffeine in your system, it continues to
1:00:27build and build.
1:00:29And now, when the caffeine finally gets
1:00:30metabolized and excreted out of your
1:00:32system, not only do you go back to the
1:00:35sleepiness that you had many hours
1:00:37before, it's that plus all of the
1:00:40adenosine sleepiness that's been
1:00:41building up during that time in between.
1:00:44So, you get hit with this huge tsunami
1:00:46wave of sleepiness, and that's what we
1:00:48call the caffeine crash.
1:00:51So, the one of the issues So, that's
1:00:54sort of caffeine in terms of how it
1:00:55works and its timing. Another issue is
1:00:57that it creates anxiety, just as you
1:01:00said.
1:01:01And anxiety is probably one of the
1:01:03greatest enemies of sleep. It's one of
1:01:05the principal reasons that underlies
1:01:07insomnia is a physiological state of
1:01:09anxiety, that your fight or flight
1:01:11branch of the nervous system is
1:01:12ratcheted up. That's what caffeine will
1:01:15do. It needs to do the opposite for you
1:01:17to fall asleep. That's why you can have
1:01:19what we call the tired but wired
1:01:20phenomenon, where you say, I'm so
1:01:22desperately tired. I am so tired,
1:01:25but I'm just so wired that I can't fall
1:01:27asleep. It's because your nervous system
1:01:29is too amped up. Caffeine will trigger
1:01:32that amping up.
1:01:33Then at that point, if you're struggling
1:01:35to fall asleep because you've got too
1:01:36much caffeine on board, it is what we
1:01:38call anxiogenic. So now you start to
1:01:41worry.
1:01:42And the last thing you need to do when
1:01:45your head hits the pillow for good sleep
1:01:47is worry. Because when you start to
1:01:48worry, you start to ruminate. And when
1:01:51you ruminate, you catastrophize.
1:01:54And when you catastrophize, you're dead
1:01:56in the water for the next 2 hours when
1:01:58it comes to sleep. Because we have this
1:02:00sense that, you know, things at night,
1:02:03in the darkness of night,
1:02:06are so much bigger than they are in the
1:02:08brightness of day.
1:02:10And we start worrying, you know, in this
1:02:12modern era, we're constantly on
1:02:14reception.
1:02:15And very rarely do we do reflection.
1:02:18Unfortunately, the only time we we
1:02:20typically do reflection is when we turn
1:02:22off the light and our head hits the
1:02:23pillow. And that is the last time you
1:02:26want to be doing reflection. So that's
1:02:28the the second problem with caffeine.
1:02:29It's anxiogenic, and it only makes you,
1:02:32sort of, almost like the Woody Allen
1:02:33neurotic of the sleep world.
1:02:35The final part of caffeine is that it's
1:02:38very good at blocking your deep sleep.
1:02:41So we've done a number of these studies
1:02:42where we'll give people a standard dose
1:02:44of caffeine, let's say, 150 mg to 200
1:02:47mg, which is probably, you know, a cup
1:02:49and a half of good strong coffee.
1:02:52And then we put you to bed and we look
1:02:53at the amount of deep sleep. And it will
1:02:55strip away your deep sleep by about
1:02:58somewhere between 15 to 30%.
1:03:01Now, to put that in context, to drop
1:03:04your deep sleep by 30%, I'd probably
1:03:06have to age you by about 40 years, 4 0.
1:03:10Or you could do it every night with an
1:03:12espresso with with dinner. And that's
1:03:14one of the problems. People will say to
1:03:16me, "Look, I'm one of those people who I
1:03:18can have two espressos with dinner and I
1:03:21fall asleep fine and I stay asleep. So,
1:03:23no harm, no foul." Well, not necessarily
1:03:26because even if you fall asleep and you
1:03:28stay asleep, you're not aware of the
1:03:30lack of the deep sleep that you're not
1:03:32getting because of the caffeine. And so,
1:03:34now you wake up the next day and you
1:03:36think, "Well,
1:03:37I don't remember having a hard time
1:03:38falling asleep. I don't remember waking
1:03:40up, but now I'm reaching for two or
1:03:42three cups of coffee the next morning
1:03:44rather than my standard one cup of
1:03:45coffee because I don't feel refreshed
1:03:47and restored by my sleep because I was
1:03:49lacking the amount of deep sleep."
1:03:51And deep sleep, what does that rob us
1:03:52of? The lack of deep sleep?
1:03:54So, lack of deep sleep deep sleep is
1:03:56critical for regulating your
1:03:57cardiovascular system. It's the time
1:03:59when we do replenish the immune system.
1:04:02It also regulates your metabolic system,
1:04:04so it controls the hormones such as
1:04:07insulin that will regulate your blood
1:04:09sugar and you will become blood sugar
1:04:10dysregulated without sufficient deep
1:04:12sleep. Upstairs in the brain, deep sleep
1:04:15will um strengthen and consolidate and
1:04:17secure new memories into your brain.
1:04:20They will prevent those memories from
1:04:21being forgotten. Deep sleep is also the
1:04:24time when we cleanse the brain of
1:04:25metabolic toxins, particularly the
1:04:27toxins that are related to Alzheimer's
1:04:29disease. So, getting a lack of deep
1:04:31sleep is, I would say, a non-trivial
1:04:33thing um
1:04:35in that regard.
1:04:37But,
1:04:38I don't want to be also puritanical here
1:04:42and this is where I'm going to change my
1:04:44title tune.
1:04:46I am not here to tell anyone how to live
1:04:49their life. I have no right to tell
1:04:51anyone how to live their life. I'm just
1:04:53a scientist.
1:04:55All I want to try and do is gift you the
1:04:57science and the knowledge of sleep so
1:04:59that you can make an informed choice.
1:05:02And after all, and the same is true for
1:05:04alcohol too and sleep, you know, life is
1:05:07to be lived to a certain degree.
1:05:10You know, no one wants to be the
1:05:11healthiest guy in the graveyard.
1:05:13I don't want to be that way, too. I want
1:05:15to live life just with moderation. The
1:05:19reason I don't drink
1:05:21uh caffeine is not because
1:05:24uh I'm so puritanical I want to be the
1:05:26poster child of good sleep. I love the
1:05:28smell of freshly ground coffee in the
1:05:30morning. It's a great ritual. It's just
1:05:32that I've read my genetics and I am one
1:05:35of the slow caffeine metabolizers. So,
1:05:37you can do these genetic kits online and
1:05:40they will tell you are you a slow
1:05:42metabolizer or a fast metabolizer. So,
1:05:44that's the variability. That's why some
1:05:46people say, "Look, I'm pretty immune to
1:05:48caffeine." And others will say, "No, I'm
1:05:49not." Um why do I now favor coffee? I
1:05:54was actually quite
1:05:56anti-caffeine
1:05:58and coffee when I first came out with
1:05:59the book, just looking at the studies.
1:06:01But now the data is immensely
1:06:03compelling. The health benefits
1:06:06associated with coffee are undeniable.
1:06:09Study after study after study. And we
1:06:11can put them all together in this big
1:06:13what we call a meta-analysis study. And
1:06:15it is so strikingly clear that coffee,
1:06:17drinking coffee, is a good thing for you
1:06:20from a health perspective.
1:06:24Two things to say about that. The first
1:06:27is that it's got nothing to do with the
1:06:30caffeine.
1:06:31And a lot of people have sort of rightly
1:06:33challenged me to say, "Look, you say how
1:06:36problematic sleep can be when you're
1:06:38drinking too much caffeine.
1:06:40But yet coffee is associated with many
1:06:43of the same health benefits that sleep
1:06:45is associated with. But coffee is
1:06:48supposed to hurt your sleep. How do you
1:06:50reconcile those two, Matt Walker?"
1:06:53And the answer is very simple.
1:06:56Antioxidants.
1:06:58Because it turns out that the coffee
1:06:59bean contains a whopping dose of
1:07:03antioxidants.
1:07:04Things such as
1:07:06it's what's other things such as
1:07:07cafestol, but it's got a bunch of
1:07:10incredible antioxidants. Probably the
1:07:12most powerful of them in terms of the
1:07:14coffee bean is something called
1:07:16chlorogenic acid. Now, don't worry, it's
1:07:18not chlorine, it's not chloride, it's
1:07:20not bleach. Chlorogenic acid is very
1:07:23different.
1:07:24And what's happened in the modern world
1:07:27is that we
1:07:28on we have and struggle with our diet so
1:07:32much because we don't eat enough whole
1:07:34foods, etc. So, what's happened is that
1:07:39the coffee bean has been now asked to
1:07:42carry the Herculean weight of all of our
1:07:45antioxidant needs on its shoulders.
1:07:49And where most people get the majority
1:07:51of their antioxidants
1:07:53is by way of drinking coffee. That's why
1:07:56coffee is associated with so many health
1:07:58benefits, and it's not the caffeine.
1:08:00Case in point, if you look at the
1:08:02studies with decaffeinated coffee, you
1:08:04get very similar health benefits.
1:08:07Again, it's not the caffeine, it's the
1:08:09coffee itself. So,
1:08:11the bottom line here is
1:08:13drink coffee, but I would say the dose
1:08:16and the timing make the poison. So, try
1:08:20to limit yourself to about two cups of
1:08:23coffee, three cups of coffee maximum,
1:08:25because if you look at the health
1:08:26benefits, by the way,
1:08:27it's a dose it's not a dose response
1:08:29where it's linear where the more and
1:08:31more coffee you drink, the more and more
1:08:32healthy you become. It peaks at about
1:08:35two to three, and then actually starts
1:08:36to go down in the opposite direction for
1:08:39lots of reasons that we can speak about.
1:08:40So,
1:08:41dose and the timing make the poison when
1:08:43it comes to coffee.
1:08:44So, you drink decaf?
1:08:45So, I do drink decaf. So, I will drink
1:08:48coffee just because I love the smell,
1:08:49and I do enjoy the taste of it, but I
1:08:52drink uh decaffeinated coffee.
1:08:54I would love to drink uh caffeinated
1:08:57coffee too, cuz I
1:08:59you know, I I'm sure
1:09:01it would be interesting cuz I work out
1:09:02day and I work out every morning and so
1:09:04many of the health coaches that I speak
1:09:06with and health professionals say, "You
1:09:09know, you should definitely get a shot
1:09:10of caffeine and it boosts your workout."
1:09:12And actually the data on that is pretty
1:09:14clear, too, that
1:09:15your lifting, for example, in the gym
1:09:17and your metabolic activity is stronger
1:09:19when you've had pre-caffeine doses.
1:09:22But it's also stronger when you sleep.
1:09:24But exactly, and that's the problem. So,
1:09:27uh and sleep is
1:09:28I would argue much more beneficial to
1:09:32health and if you're trying to work out
1:09:34or you're trying to uh be an athlete or
1:09:36perform,
1:09:37sleep will trump caffeine five ways till
1:09:40Tuesday. I mean, sleep is probably the
1:09:43very best legal performance-enhancing
1:09:46drug that we know of that not enough
1:09:48athletes are abusing.
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1:10:51One of the other sort of ongoing
1:10:52stereotypes that I've always wondered if
1:10:53it was wrong or right or whatever, now I
1:10:55get to a chance to ask you is about this
1:10:57culture of sleep medication. So I've got
1:11:00some friends who who might have I don't
1:11:03know prescribed sleep medication but
1:11:04I've got a lot of friends also that use
1:11:07what they call sort of natural they
1:11:08always use the word natural natural
1:11:10something so it's like natural sleep
1:11:13tablets.
1:11:14What's your perspective on this culture
1:11:15of us
1:11:17humans taking sleep tablets to get them
1:11:20to feel sleepy and go off to sleep at
1:11:21night?
1:11:22Usually when people ask me that question
1:11:24personally I the first thing I ask them
1:11:26is why is it that you think you're not
1:11:28able to sleep?
1:11:30And try to reverse engineer the question
1:11:32from there before we even start thinking
1:11:34about sticking band-aids on wounds I
1:11:37firstly want to ask what's causing the
1:11:39infection because we can keep bandaging
1:11:42it for all we like but if it keeps
1:11:45festering it's probably not going to go
1:11:47away anytime soon.
1:11:48Is it a problem to keep bandaging it?
1:11:50It is a problem. Right now we don't
1:11:53typically advocate sleeping pills as the
1:11:55first line defense agent against or for
1:11:58insomnia as a treatment. In fact in 2016
1:12:02the American and again this is me simply
1:12:04describing the science. This is me being
1:12:07descriptive of the science not
1:12:09prescriptive in in terms of medicine cuz
1:12:12I'm not a medical doctor.
1:12:14Um
1:12:15but in 2016 the American College of
1:12:18Physicians they had a expert panel who
1:12:21surveyed all of the literature on
1:12:22classic sleeping pills and what they
1:12:25suggested was that sleeping pills must
1:12:27no longer be the first line treatment
1:12:30for insomnia it has to be cognitive
1:12:33behavioral therapy for insomnia or what
1:12:34we call CBT-I which is a psychological
1:12:37intervention that we can speak about.
1:12:39But their recommendation was that they
1:12:40found
1:12:42I think their wording was um small and
1:12:45of questionable clinical importance in
1:12:48terms of the benefits of sleeping pills.
1:12:50Now
1:12:51there is a time and a place
1:12:53for in clinical medicine for sleeping
1:12:55pills, but usually as an adjunct in
1:12:58combination with cognitive behavioral
1:13:00therapy.
1:13:01They are not advocated for long-term
1:13:04use, but so they usually advocated for
1:13:06short-term use, weeks.
1:13:08Most people have been on them for months
1:13:10if not years, these classic sleeping
1:13:12pills, and that's a problem
1:13:14because those sleeping pills are in a
1:13:16class of drugs that we call the sedative
1:13:18hypnotics.
1:13:20And sedation is not sleep.
1:13:23For sub- subset of some people, there
1:13:25are some of these {quote} {unquote}
1:13:28sleep supplements that may benefit, but
1:13:31overall, the studies are very clear.
1:13:34None of them are efficacious.
1:13:37And when you think about it, it makes
1:13:39sense.
1:13:40You know, if there was some cheap sleep
1:13:42supplement that you could buy on Amazon
1:13:44that was the Shangri-La of good sleep,
1:13:47that was this miracle sleep drug,
1:13:50don't you think that a pharmaceutical
1:13:52company would have patented it 20 years
1:13:53ago and be making billions of dollars
1:13:55from it? You know, that alone tells you
1:13:57all that you need to know about, you
1:13:59know, these natural sleep supplements.
1:14:02Cognitive behavioral therapy for
1:14:03insomnia though
1:14:04Yeah.
1:14:05seems to be the kind of the front line
1:14:06of
1:14:07prescribed defense against a lack of
1:14:09sleep insomnia conditions. What exactly
1:14:12is that therapy aiming to do? What like
1:14:15what does it do for for somebody?
1:14:17Great question. So, in some ways, the
1:14:20the title um tries to suggest what it
1:14:23what it does, but not particularly well,
1:14:24perhaps. So, it focuses on cognitive
1:14:28aspects, and it focuses on behavioral
1:14:30aspects.
1:14:31So, for the cognitive aspects, when we
1:14:34do cognitive behavioral therapy working
1:14:36with the patient, we'll try to focus on
1:14:38thoughts and beliefs and ideas around
1:14:41sleep. Do they have anxiety around the
1:14:43bedroom? Most of them do.
1:14:45I can't sleep.
1:14:46Because I can't sleep. So, every time I
1:14:48walk into the bedroom, my bed is the
1:14:50enemy. And I look at the bedroom and I
1:14:52look at the bed, and I just know that
1:14:54that means I'm going to have a bad night
1:14:56of sleep. So, what's happened is that at
1:14:59that point, your sleep controls you.
1:15:03And you've lost all confidence in your
1:15:05ability to sleep. And we need to course
1:15:08correct that. So, one of the things we
1:15:09do in cognitive behavioral therapy is
1:15:11that we lower that anxiety. And we say,
1:15:13"Look, everyone has a bad night of
1:15:15sleep, even a bad couple of nights of
1:15:17sleep. In fact, I will tell you, I don't
1:15:20sleep perfectly well all the time, too.
1:15:21I've had at least two very severe bouts
1:15:23of insomnia in my life.
1:15:26We all have a bad night of sleep. It
1:15:28doesn't mean that tomorrow you're going
1:15:30to wake up with depression or
1:15:32Alzheimer's disease. Don't worry, you're
1:15:34not going to get cancer, you know,
1:15:36tomorrow, just because you've had a bad
1:15:37night of sleep. So, we start to change
1:15:39people's misbeliefs about sleep. And we
1:15:42try to get them back from being
1:15:44catastrophic about this idea of my not
1:15:46sleeping.
1:15:48So, we That's the cognitive aspect. We
1:15:50start to lower their anxiety around the
1:15:52bed and and the bedroom. We start to try
1:15:55to build confidence back. We start to
1:15:57reduce their expectations about, you
1:16:00know, what is reasonable sleep? Well,
1:16:02right now you're getting 4 or 5 hours of
1:16:04sleep, and we can do better. But, don't
1:16:07start thinking that you need to get 8
1:16:09hours of sleep straight out the box.
1:16:11Let's just manage it.
1:16:12That's just because it's going to stress
1:16:13you out, right?
1:16:14It's only going to make my sleep worse.
1:16:15Right. Okay.
1:16:16You know, when you're struggling with
1:16:17sleep in the middle of the night and
1:16:18you're wide awake,
1:16:20you're laying in bed and you're
1:16:20thinking, "Oh my god, I've got 5 hours
1:16:22left before I've got to go to work."
1:16:23It's terri- It's the last, you know,
1:16:25it's a little bit like trying to
1:16:26remember someone's name. The harder you
1:16:28try, the further you push it away.
1:16:31So, would you say in that What What do I
1:16:32do in that situation? You It's 2:00 a.m.
1:16:34in the morning, you've got to be up at
1:16:357:00, there's a flight you're getting
1:16:37on, say, whatever.
1:16:38Yeah.
1:16:38What should one do? Cuz
1:16:40from what I was reading in chapter 14, I
1:16:42was I was hearing that maybe I should
1:16:44get out of bed.
1:16:45Or not just sit there and ruminate.
1:16:48You know, into the early hours of the
1:16:49morning. Or do I stay in bed and do
1:16:51something?
1:16:52What does one do?
1:16:54The prototypical recommendation is that
1:16:57after about 30 minutes of time awake,
1:16:59you should get out of your bed and you
1:17:01should just go to a different room and
1:17:02do something like, you know, read a book
1:17:05or listen to a podcast. Don't eat cuz it
1:17:07then trains your brain to wake up to do
1:17:10that. Don't start working or getting in
1:17:12front of a computer screen, you know. I
1:17:14said listen to a podcast, sure, you
1:17:16know, just make sure your phone's in you
1:17:18know, you don't start scrolling anymore
1:17:19than that. But you can do relaxing
1:17:21things, stretch, meditate.
1:17:24The reason is because if you start to
1:17:26spend a lot of time awake in your bed,
1:17:28your brain is an incredibly associative
1:17:30device. And very quickly, it will start
1:17:32to learn that this thing called your bed
1:17:34is this place where I'm always awake.
1:17:37And therefore, you start to learn
1:17:39through this
1:17:40repeated loop of behavior that I'm
1:17:43always going to be wide awake in bed.
1:17:44And we need to break that association,
1:17:46and that's why we say get out of bed
1:17:48after about 30 minutes, cuz you're just
1:17:49training your brain to think that this
1:17:51thing called my bed is the place where
1:17:53I'm never asleep. And we want to break
1:17:55that.
1:17:56And only return to bed when you're
1:17:58sleepy, and there's no time limit for
1:17:59that. And that way, gradually, it's much
1:18:02better because you will relearn the
1:18:03association that your bed, just as when
1:18:05you were young, was guaranteed that your
1:18:07bed is this place where you will always
1:18:09be asleep.
1:18:10The problem with that is many people
1:18:12don't want, you know, it's the middle of
1:18:13the night, it's dark, it's cold. I I'm
1:18:16not I'm just not going to get out of
1:18:17bed. So, what's your other what what
1:18:20else have you got in your toolbox, Matt?
1:18:23Um
1:18:23at that point, I would say, "Okay,
1:18:25that's reasonable."
1:18:27The first thing I would suggest is
1:18:28meditation.
1:18:29You know, I am a hard-nosed scientist,
1:18:31and when I was researching that the
1:18:34book,
1:18:35I was, you know, I just thought this
1:18:37sounds all a bit woo-woo and you know, I
1:18:39I live and work in Berkeley, California,
1:18:42which is kind of, you know, the free
1:18:44speech, you know, flower power movement,
1:18:46San Francisco, flowers in your hair
1:18:47business. I just thought this is all a
1:18:49bit, you know,
1:18:51holding hands and singing Kumbaya. This
1:18:53is This is not for me, this this
1:18:55meditation stuff. I couldn't get away
1:18:57from the strength of the data. It was
1:18:59immensely powerful regarding sleep and
1:19:01its benefits on insomnia and sleep. So,
1:19:04I started meditating and now I meditate
1:19:09for 10 minutes before bed every single
1:19:11night and I've been doing that for about
1:19:134 years. So, I would say if even if it's
1:19:16in the middle of the night and if I wake
1:19:17up in the middle of the night, I'll
1:19:18start try to walk myself through a
1:19:20meditation.
1:19:21Um
1:19:22You You referenced there
1:19:24listening to podcasts, etc., etc. You
1:19:26know, doing something else to stimulate
1:19:27the brain. I when I go to bed, I have to
1:19:30have something playing. I say have to. I
1:19:31shouldn't be that definitive. I like to
1:19:34have something playing, some kind of
1:19:36sound or noise, whatever. And much to my
1:19:39partner's dismay,
1:19:41my
1:19:42content of preference is
1:19:45serial killer
1:19:48podcasts or documentaries or just like
1:19:50something which is really going to grab
1:19:52hold of my brain and focus me. So,
1:19:55something like It has to be really
1:19:57interesting to me for me to be able to
1:19:58focus on it. My partner is the opposite
1:20:00again. She likes um
1:20:03silence.
1:20:04Why do I listen to serial killers?
1:20:08It's different for different people's
1:20:09constitutions, you know, and
1:20:11psychologies.
1:20:13Uh and you know, I can pathologize you
1:20:15all you like if if you would wish me to,
1:20:17but I would say it
1:20:19what's fundamentally going on here with
1:20:21meditation and I'll come back to an
1:20:23alternative, too, but the reason why
1:20:26some meditation apps as well have now
1:20:28started to do what's called sleep
1:20:30stories, which in some ways is what
1:20:32you're doing a version of with your
1:20:34podcast,
1:20:36is hark back to when we were kids. You
1:20:38know,
1:20:40for many parents, they would just read a
1:20:41book to the kid. You know, the
1:20:43children's books, good night books.
1:20:45Because you would read the child to
1:20:47sleep.
1:20:48And for some reason,
1:20:51we as we developed into adults, we
1:20:53thought, well, we no longer benefit from
1:20:56having a story read to us to help us
1:20:57sleep.
1:20:58No, it's not true. We
1:21:00we benefit hugely. In fact, the the
1:21:02meditation company Calm, you know, was
1:21:05saved by the introduction of sleep
1:21:08stories into their app. They were doing
1:21:09pretty well as a meditation app, but
1:21:11then they started to do sleep stories
1:21:13and it became a unicorn company um in
1:21:16terms of its valuation. It broke a
1:21:18billion dollars.
1:21:20And it was on the
1:21:21the back of sleep stories.
1:21:23And what they realized is that people
1:21:25were self-medicating their insomnia by
1:21:27way of meditation.
1:21:29So, they latched onto that and then they
1:21:31found that these stories, sleep stories,
1:21:33were great. And you've got now wonderful
1:21:35people, people who you've interviewed on
1:21:36the show. So, what you're doing and what
1:21:39those sleep stories are doing and what
1:21:41meditation is doing, it's all the same
1:21:43thing,
1:21:44which is that it is taking your mind off
1:21:47itself.
1:21:49Because when you are struggling to sleep
1:21:51or you've woken up in the middle of the
1:21:53night,
1:21:54what you don't want to be doing is
1:21:56focusing on either what you
1:21:59what you What did I do today? What did I
1:22:02not do today? What did I do poorly? Oh
1:22:04my goodness, what have I still got to do
1:22:05tomorrow? And at that point, things are
1:22:08just a disaster. You're wide awake.
1:22:12What all of the things that we've just
1:22:14discussed do is they take your mind off
1:22:17itself.
1:22:18And at that point, then you start to
1:22:21allow sleep to come back naturally.
1:22:24That's why one of the other suggestions
1:22:26is take yourself for a mental walk.
1:22:28So, don't count sheep, by the way, that
1:22:30doesn't work. A colleague of mine at UC
1:22:32Berkeley did the study. Actually, takes
1:22:34you longer to fall asleep if you're
1:22:35counting uh sheep. What she found that
1:22:38the Dr. Allison Harvey was that if you
1:22:40just close your eyes and you think about
1:22:42a walk that you take frequently, let's
1:22:44say it's a walk with the dog,
1:22:46and you think about it in high-fidelity
1:22:48detail. So, I close my eyes, I go out
1:22:51the door, take a left down the steps,
1:22:53then I'm going to go up the street, I
1:22:54take the first left past that pine tree.
1:22:57That's the level of detail. If you just
1:22:59walk yourself on that mental walk, sure
1:23:01enough, people fall asleep in about 50%
1:23:04less time, half the time it takes.
1:23:06This is the thing with sleep stories and
1:23:07also my serial killer documentaries or
1:23:10serial killer podcasts that I listen to.
1:23:12Detail.
1:23:13Exactly.
1:23:14You get even I've listened to
1:23:16Calm's sleep stories before, and the
1:23:19attention to detail in the sort of
1:23:21descriptive nature of what they're
1:23:22saying is so apparent. They'll say
1:23:24things like,
1:23:25"The cold, wet window sill saw the
1:23:28raindrops like
1:23:30um tapping against it one by one by one
1:23:34by one." And that sounds very similar to
1:23:36my serial killer documentaries when I
1:23:37hear about the serial killer coming in
1:23:38through the window.
1:23:39Yeah. Yeah. Yeah.
1:23:40At night time. Um
1:23:42and I wondered why the descriptive
1:23:44nature of it, the detail matters for
1:23:46dozing us off.
1:23:47And because it prevent I mean, you've
1:23:49got limited bandwidth in terms of
1:23:50cognitive capacity.
1:23:51Right.
1:23:52And if you're consumed and you saturate
1:23:54your bandwidth with that level of
1:23:56detail, it's very hard for any of these
1:23:58other things called our worries and our
1:24:00anxieties to start entering into our
1:24:03mind. The other thing I would note, by
1:24:04the way, though, is
1:24:06if you are if none of these things are
1:24:08working for you, if the fictional notion
1:24:11of serial killing is not working for
1:24:13you, if meditation is not working for
1:24:15you, if going on a mental walk is not
1:24:18working for you,
1:24:20this is the final suggestion I have. If
1:24:21you're lying there awake, firstly, by
1:24:24the way, if you're struggling with
1:24:25sleep, remove all clock faces from your
1:24:27bedroom. It's one of the best pieces of
1:24:29advice I can give you.
1:24:30Knowing what time of night it is is no
1:24:33favor.
1:24:34So, knowing now that it's 3:23 a.m. in
1:24:38the morning and I'm still struggling to
1:24:40fall asleep, and then I look back at the
1:24:41clock and it's now 4:03 a.m. and I've
1:24:44still been awake, and now it's 4:27 and
1:24:47I've got to wake up at 6:30 a.m. Knowing
1:24:50that
1:24:51has no utility for you. Remove all clock
1:24:55faces from your bedroom. It is a gift.
1:24:58But, coming back to the final
1:25:00suggestion, if you don't want to get out
1:25:02of bed, if you don't want to listen to a
1:25:03podcast,
1:25:05the final thing I would say is just
1:25:07accept and say, "Look, it's okay.
1:25:09Tonight is not my night. It is not the
1:25:12worst thing in the world. And instead of
1:25:15trying to sleep, all I'm going to do
1:25:17here is lie in bed,
1:25:19and I'm just going to rest."
1:25:22Because wouldn't it be lovely if someone
1:25:24came to you in the middle of your work
1:25:25day,
1:25:26you're just stressed and someone said,
1:25:28"By the way, just come into this room.
1:25:30There's a There's a bed here. Just lie
1:25:32down and just rest for an hour."
1:25:35Wouldn't it be lovely? Just have a good
1:25:36old rest for an an hour. Just rest
1:25:39there.
1:25:41And I would say that if you can't sleep,
1:25:43just lie in bed, stop worrying about
1:25:45sleep and not being able to get it, stop
1:25:47worrying about the next day, just lie in
1:25:49there and enjoy a nice good old rest.
1:25:54And by the way, usually what happens is
1:25:56that after you start thinking, "Okay,
1:25:58I'm going to rest," the next thing you
1:25:59remember is the alarm clock going off at
1:26:016:30 because finally you stopped trying
1:26:04and sleep happened. So, yeah.
1:26:05Of course. You know, prolonged one of
1:26:08the things I've also I wonder if this is
1:26:09a if I'm wrong about this is I sometimes
1:26:13thought that, you know, I could go
1:26:14Monday to Friday and kind of sacrifice
1:26:16my sleep. This was specifically when I
1:26:18was really in the height of like running
1:26:19big businesses, etc.
1:26:21Um and then on the weekend I'll just
1:26:22make up for it.
1:26:24So I thought, you know, I could go
1:26:25Monday to Friday, I'll sleep maybe
1:26:26sometimes 2 hours a night, 3 hours a
1:26:28night, whatever. Then Saturday, you
1:26:29know, I'll just do a, you know, 11-hour
1:26:32sleeping and I'll just make up for it.
1:26:33Yeah.
1:26:36Is that a good strategy?
1:26:39The delightful laughter at the end of
1:26:41your sentence that uh
1:26:43I think probably tells you the answer
1:26:44that you know. Um
1:26:46unfortunately, sleep doesn't work like
1:26:49that. It would be nice if it did. Sleep
1:26:51is not like the bank. In other words,
1:26:53you can't accumulate a debt
1:26:56as you were doing during the week and
1:26:57then hope to try and pay it off
1:27:00at the weekend.
1:27:01Um
1:27:02So for example, let me take an extreme
1:27:04version of that experiment. Let me take
1:27:06you tonight. I'm going to deprive you of
1:27:08sleep for an entire night for, let's
1:27:10say, 8 hours of sleep. And then tomorrow
1:27:12night I'm going to give you all of the
1:27:14recovery sleep that you want, as much as
1:27:16you wish for. And then the next night
1:27:18you can have all of the recovery sleep
1:27:21that you want. And even on the third
1:27:22night,
1:27:23will you sleep longer that first
1:27:26recovery night after a night of no
1:27:28sleep? Absolutely, you will sleep
1:27:30longer.
1:27:32But across those three or four recovery
1:27:33nights of sleep, will you get back all
1:27:36of the sleep that you lost? Not even
1:27:37close. You'll maybe only sleep back
1:27:39about four, four and a half of the 8
1:27:42hours that you lost. In other words, by
1:27:45that stage, you are four or three and a
1:27:47half hours in overdraft on your sleep
1:27:51bank account. You went into debt and you
1:27:53only paid about 50% of it back. So
1:27:56what's happening with you during the
1:27:58week is that you're accumulating this
1:28:00debt,
1:28:01you know, of maybe 10 hours. You're
1:28:03short-changing, you're only sleeping
1:28:04like 6 hours a night for the five nights
1:28:07during the week. And then you binge on
1:28:09sleep and you try to maybe sleep 10
1:28:11hours or 11 hours, that's only two or
1:28:14three extra hours. So, sum total that's
1:28:17only four to six, you know, hours of
1:28:21made-up sleep
1:28:23relative to the 10 hours of debt. So,
1:28:25what happens is that that next week, you
1:28:27now carry forward four hours of your
1:28:30debt.
1:28:31And then next weekend, you try to sleep
1:28:34it back, but you're still four hours
1:28:35lost. So, now you've got eight hours of
1:28:37net debt. In other words, what it
1:28:39develops is into a compounding interest
1:28:41on a loan. It just starts to escalate
1:28:43ballistically across weeks, across
1:28:45years, and across the lifespan.
1:28:47And then what happens in terms of
1:28:50health outcomes? So, say that I did that
1:28:52for a couple of years. Say that I
1:28:53sustained that pattern of, you know,
1:28:55depriving myself of sleep throughout the
1:28:56week, maybe catch up on Saturday,
1:28:58Yeah.
1:28:58depriving myself again the next week,
1:29:00catch up on Sunday, deprive myself the
1:29:02next week, and I did that pattern for
1:29:04multiple years. What would What would be
1:29:06the health implications?
1:29:08So, you can describe them short, mid,
1:29:12and long-term.
1:29:14The first thing I would say though is
1:29:15that the elastic band of sleep
1:29:16deprivation will stretch only so far
1:29:18before it snaps.
1:29:20The short-term,
1:29:22you know, probably the most immediate
1:29:23short-term consequence is that you are
1:29:26popped out in a driving-related
1:29:28accident, drowsy-related accident.
1:29:32Because drowsy-related accidents are
1:29:34non-trivial. They make up a large
1:29:37proportion of accidents on our streets
1:29:40in terms of human error-full driving.
1:29:42When you say popped out
1:29:44out of the gene pool.
1:29:46Okay. So, what happens is that when you
1:29:48are under-slept, you're at the wheel and
1:29:50you start to have what we call
1:29:51microsleeps,
1:29:53where your eyelid will partially close.
1:29:55Now, you are not aware of it. You have
1:29:57no awareness of it whatsoever. And in
1:29:59fact, parts of your brain seem as though
1:30:01they're almost falling asleep. Like
1:30:03you're having this microsleep, and it
1:30:04lasts for about a second or two seconds.
1:30:07Now, if you're on the motorway and
1:30:08you're traveling at 70 mph
1:30:10and you have a 2-second microsleep,
1:30:13that's enough time for you to drift from
1:30:15one lane into the next. If you're just
1:30:17in a two on a two-lane, you know, sort
1:30:20of
1:30:21backstreet
1:30:22where there's oncoming traffic in the
1:30:24other direction
1:30:25and you're traveling at 40 mph and you
1:30:27drift halfway into that lane,
1:30:30that's oncoming traffic. So,
1:30:32in other words, if you have a microsleep
1:30:34at 60 or 70 mph, at that point there's a
1:30:382-ton missile traveling at 60 mph and no
1:30:41one's in control.
1:30:42And that may be the last microsleep that
1:30:44you ever have in your life.
1:30:46Obviously, all the other things you've
1:30:48mentioned would be implications, things
1:30:49like performance drop, and sort of
1:30:51memory, relationships, libido would all
1:30:54drop off. So, I wouldn't be having as
1:30:55much sex, I wouldn't you wouldn't have
1:30:56all those things. Then mid-term.
1:30:58So, mid-term, then you're going to
1:30:59escalate those things into more disease
1:31:01state. So, for example, if I were to
1:31:03take an individual and people have done
1:31:05these studies, not not we, but um where
1:31:07you limit them to let's say 4 or 5 hours
1:31:09of sleep for 1 week,
1:31:11your levels of blood sugar are disrupted
1:31:14so significantly that your doctor at the
1:31:17end of that 1 week would classify you as
1:31:19being pre-diabetic.
1:31:21So, that's you could almost argue that
1:31:23short-term, not mid-term.
1:31:25Mhm. Yeah.
1:31:25Um you know, one if you're a male and I
1:31:29limit you to 4 or 5 hours of sleep, a
1:31:31healthy young male,
1:31:33um for 1 week, I will drop your levels
1:31:36of testosterone to that of someone who
1:31:38is 10 years older than you. So, I can
1:31:40age you by a decade just by short
1:31:43sleeping you for 1 week. We see
1:31:46equivalent impairments in female
1:31:47reproductive health in estrogen,
1:31:49luteinizing hormone, and
1:31:50follicle-stimulating hormone.
1:31:52Um so, it's both men and women.
1:31:55Your blood pressure will start to creep
1:31:57up, your systolic blood pressure in
1:31:59particular will creep up. Your heart
1:32:01rate in terms of its um contraction
1:32:03rate. In other words, your the the speed
1:32:05of your heart starts to increase.
1:32:07The progression into obesity, diabetes,
1:32:10cardiovascular disease, mental health
1:32:13issues, anxiety, depression,
1:32:15suicidality,
1:32:17all of these things, immune compromise,
1:32:19infection.
1:32:21All of those things can be termed, you
1:32:23know, will be mid-term. Now, all of
1:32:25those things have a longer-term tail to
1:32:27them, which is this thing called
1:32:29premature mortality. So, using that
1:32:31sweet spot of 7 to 9 hours of sleep, you
1:32:34can argue that there's a simple truth on
1:32:36the basis of the data. The shorter your
1:32:38sleep, the shorter your life. That short
1:32:40sleep will predict or cause mortality.
1:32:43Is that supported by the by data?
1:32:44That's supported by data, yeah. Now,
1:32:46there's an interesting change there,
1:32:48which is once you get past about 9 or 10
1:32:50hours, your mortality risk doesn't just
1:32:52keep going down and down. It will hook
1:32:54back up again, as if almost too much
1:32:57sleep is a bad thing, and we can explain
1:32:59why that is the case as well, and why
1:33:01it's probably not quite as simple as
1:33:03that. But, the final long-term
1:33:05consequence that I would say is
1:33:07Alzheimer's disease. You know, the two
1:33:09most feared diseases in developed
1:33:10nations are cancer and Alzheimer's
1:33:12disease. Both of them have links to
1:33:14insufficient sleep, many of them causal.
1:33:17And this relationship between sleep and
1:33:19Alzheimer's disease, this is where we
1:33:20actually do, I'd probably say almost 50%
1:33:23of the work that I do at my sleep center
1:33:24is focused on sleep and Alzheimer's
1:33:26disease.
1:33:27And there, the data is stunning, I would
1:33:29say.
1:33:30At this stage, insufficient sleep seems
1:33:32to be one of the more or one of the most
1:33:37significant lifestyle factors that can
1:33:40develop or dictate the development of
1:33:43Alzheimer's disease later in life. Now,
1:33:45that's a lifestyle factor. There are
1:33:47other genetic factors, but certainly we
1:33:49now know that it's not just that
1:33:51insufficient sleep
1:33:53predicts a greater amount of Alzheimer's
1:33:57pathology in your brain. So, for
1:33:58example, people who on average are
1:34:00sleeping 6 hours or less have a far
1:34:02higher magnitude of amyloid of beta
1:34:06amyloid, which is the sticky toxic
1:34:07protein related to Alzheimer's disease,
1:34:09and another protein called tau protein.
1:34:11These are the two protein culprits of
1:34:13Alzheimer's. Both of those are escalate
1:34:17the less and less sleep that you have.
1:34:18Now, that's just associational. We also
1:34:20know, by the way, that two sleep
1:34:21disorders, insomnia and sleep apnea,
1:34:23heavy snoring, both of those are
1:34:25associated with a marked increased risk
1:34:28of your Alzheimer's disease of
1:34:30Alzheimer's disease later in life.
1:34:32That's simply associational. That
1:34:33doesn't prove causality, but we now have
1:34:36the causal evidence both in animal
1:34:38models and in human models. If I deprive
1:34:41a human being of sleep for single night,
1:34:43or I even just deprive you of deep sleep
1:34:46for a single night, the next day we can
1:34:48see an immediate increase in these
1:34:50Alzheimer's disease-related proteins
1:34:52circulating in your bloodstream,
1:34:54circulating in what we call a
1:34:56cerebrospinal fluid that bathes the
1:34:58brain, and using special brain scans, we
1:35:00can even measure it within the brain
1:35:02itself.
1:35:04So, these are causal manipulations. It's
1:35:06not associational. I manipulate this
1:35:08thing called sleep, and the consequence
1:35:10is that I manipulate your Alzheimer's
1:35:12disease proteins.
1:35:14That's correlation going to causation.
1:35:16Then the question is, well, mechanism.
1:35:20What is it about sleep when you get it
1:35:22that is de-escalating Alzheimer's
1:35:24disease risk?
1:35:25In other words, when you don't get it,
1:35:28what why would it increase your
1:35:29Alzheimer's risk? And this is a stunning
1:35:31discovery made by a scientist called
1:35:33Maiken Nedergaard at the University of
1:35:35Rochester here in America.
1:35:37And she found three things. First,
1:35:39studying mice and rats, she found that
1:35:42the brain has a cleansing system. Now,
1:35:45we didn't used to think that your brain
1:35:47had a cleansing system. Your body had
1:35:49one, and everyone knows what it's
1:35:51called. It's called the lymphatic
1:35:53system.
1:35:54Um we didn't think the brain had one,
1:35:56but she discovered that the brain has
1:35:57one. It's called the glymphatic system,
1:36:00named after these glial cells that make
1:36:02it up.
1:36:03The second thing that she discovered is
1:36:04that that cleansing system within the
1:36:07brain is not always switched on in high
1:36:10flow volume across the 24-hour period.
1:36:13It was expressly during sleep and
1:36:15particularly during deep non-REM sleep
1:36:18when that sort of sewage system was put
1:36:21into overdrive and washed away all of
1:36:24this detritus that built up during the
1:36:26day.
1:36:27And the final thing that she discovered,
1:36:30and this is why it's related to
1:36:31Alzheimer's disease, is that two of the
1:36:33metabolic byproducts that build up
1:36:35during the day in our brain
1:36:37are beta amyloid and tau protein,
1:36:40the two bad actors in Alzheimer's
1:36:43disease.
1:36:44So, in other words, what she discovered
1:36:45is a system of, you know, good night
1:36:47sleep clean. That sleep is a power
1:36:50cleanse for the brain.
1:36:52And if you're not getting your sleep
1:36:53every night, you know, it doesn't mean
1:36:55that you're going to get Alzheimer's
1:36:57disease next week. It doesn't mean that
1:36:58you're going to get Alzheimer's disease,
1:36:59you know, in a year's time.
1:37:01But night after night, once again, it's
1:37:04like compounding interest on a loan.
1:37:06And that's why we now believe through
1:37:08this causal mechanism that insufficient
1:37:10sleep is a risk factor for Alzheimer's
1:37:12disease.
1:37:13Lots of people will say to me, "Look,
1:37:15there are these individuals in society
1:37:17who claim that they, you know, didn't
1:37:21very much sleep, who didn't sleep a
1:37:22lot." You know, Margaret Thatcher is
1:37:24often quoted me uh quoted to me about
1:37:26that. You know, um
1:37:29uh Ronald Reagan was apparently another
1:37:31short sleeper.
1:37:33I don't think it's coincidental that
1:37:35both Thatcher and Reagan went on to die
1:37:39of the unfortunate disease of
1:37:42Alzheimer's.
1:37:45I'm I'm sold.
1:37:47Sleep is important, I get it.
1:37:49I'm sold.
1:37:51How do I
1:37:53My question is, what are the things that
1:37:56in the modern society are standing in
1:37:58the way of sleep? We've touched on some
1:38:00of them loosely, but some of the like
1:38:01big obvious things, the things that you
1:38:03would suggest doing, very actionable
1:38:05things we could do straight away to
1:38:07improve our chances of having that
1:38:09healthy
1:38:11deep sleep that we need to be optimal in
1:38:14every regard of our health and
1:38:15performance.
1:38:16There's probably, I think, five standard
1:38:19tips, what we call sort of sleep
1:38:21hygiene, that you can do. And then I'll
1:38:22come on to maybe just some
1:38:23unconventional tips that we've sort of
1:38:26touched on. And we've spoken about many
1:38:28of these. The first thing I would
1:38:29recommend people to do, and this is why
1:38:31when some people say, "How What about
1:38:33this new sleep supplement?" Or, you
1:38:35know, it's it's 40 quid for this bottle
1:38:37of these sleep
1:38:38new sleep natural medications, so I'm
1:38:40going to give it a try. I would say, try
1:38:42these tried-and-true things first before
1:38:45you spend your money on supplements. The
1:38:47first thing is regularity.
1:38:49Go to bed at the same time and wake up
1:38:51at the same time, no matter whether it's
1:38:52the weekday or the weekend.
1:38:54Your brain expects regularity. It
1:38:57thrives best under conditions of
1:38:58regularity. When you give it regularity,
1:39:01you can improve the quantity and the
1:39:03quality of your sleep.
1:39:05The second thing is get some darkness at
1:39:08night. As I said, we don't get enough
1:39:09darkness in the modern world.
1:39:12And so, the trick I would offer, and I
1:39:15don't use it I don't like the word hack,
1:39:16but the sort of suggestion would be in
1:39:19the last hour before bed,
1:39:22try this experiment for everyone
1:39:23listening for the next week,
1:39:26dim down half of the lights or switch
1:39:28off half of the lights, or even a
1:39:30three-quarters of the lights in your
1:39:32home in the last hour before bed.
1:39:35All of the lights in every room?
1:39:36In all of the rooms, you know, switch
1:39:39off almost all of the light. Now, I'm
1:39:41not suggesting be unsafe and walk around
1:39:43in the darkness in the last hour. That's
1:39:44not what I'm saying. Just dimmed out,
1:39:46you know, switch off half of the lights.
1:39:49You will be surprised at how sleepy that
1:39:52darkness will make you feel. And it's
1:39:54also an incredible behavioral trigger
1:39:58to
1:40:00signal to your brain that it is time for
1:40:04sleep, that darkness is around me.
1:40:06That's the second tip is darkness. The
1:40:08third tip tip is temperature.
1:40:11Most people sleep in an ambient bedroom
1:40:13temperature that is too high.
1:40:15And you need to aim for a bedroom
1:40:17temperature of about 18 18 and 1/2
1:40:20degrees Celsius or around about 65 to 68
1:40:23degrees Fahrenheit if I'm I'm probably
1:40:25butchering the the mathematics there on
1:40:27that, but um
1:40:29you need to get cool. Now, you can wear
1:40:31thick socks, you can have a hot water
1:40:32bottle. That's fine, but the ambient
1:40:35needs to be cold.
1:40:37Because you need to drop your core body
1:40:39temperature and your brain temperature
1:40:41by about 1 degree Celsius to fall asleep
1:40:43and stay asleep.
1:40:44And it's the reason that you will always
1:40:46find it easier to fall asleep in a room
1:40:48that's too cold than too hot.
1:40:50So, make your bedroom cold. Make it dark
1:40:53like cave.
1:40:54The the fourth question would be sort of
1:40:58what we've or fourth suggestion would be
1:41:01walk it out and we've spoken about this,
1:41:03the 30-minute rule, you know, get up, do
1:41:05something different or meditate,
1:41:07you know, don't lie in bed awake for too
1:41:09long. Then the final two things we've
1:41:11spoken about Well, we spoke about
1:41:12caffeine.
1:41:14We haven't spoken about alcohol, but let
1:41:16me just say as the kind of headline of
1:41:18it, alcohol is not a sleep aid. Many
1:41:20people use it as a sleep aid. It is not
1:41:23your friend. Alcohol again is a
1:41:25sedative, so it knocks you out. The
1:41:27second is that it fragments your sleep.
1:41:29So, you wake up, your sleep is littered
1:41:31with all of these small awakenings. Most
1:41:34of them you don't remember cuz it's too
1:41:35brief, but it makes for miserable lousy
1:41:38quality sleep. And the final thing is
1:41:40that it alcohol is very good at blocking
1:41:42your REM sleep or your dream sleep,
1:41:43which we know is critical for many other
1:41:45functions as well. So, alcohol's not
1:41:47your friend. That's the sort of the
1:41:48final tip. Again, you know, just every
1:41:51if you're with friends, have a glass of
1:41:54red wine. Just know, okay, my sleep's
1:41:56not going to be great that night.
1:41:58Yeah, okay.
1:41:59I mean, that's you know, I'm not yeah,
1:42:01I'm
1:42:03whatever it's just, you know, live life
1:42:05Of course, yeah.
1:42:05I'm not saying that.
1:42:06I I was I was thinking there about the
1:42:08other sort of behavioral things that we
1:42:10do that harm our sleep as well. We
1:42:12talked about coffee earlier on, avoiding
1:42:13that. It's weird that people drink it
1:42:15after dessert in the evenings. I've
1:42:17never understood that. Guess that's an
1:42:18old tradition. Um but the other thing
1:42:20obviously that the modern generation are
1:42:22even more susceptible to is to
1:42:24have a quick TikTok. Look at the social
1:42:26media account or something. Now, I
1:42:29thought, you know, there's a lot of
1:42:30different products out there that are
1:42:32trying to help with the the the light
1:42:34that comes from these screens that I
1:42:35think is the cause of what's keeping us
1:42:37awake. But there's this little button
1:42:39called dark mode on my iPad. Oh, there's
1:42:41also one called night shift. So, if I
1:42:43just pop that on,
1:42:46Bob's your uncle.
1:42:47And this and I can crack on with my
1:42:49screen time.
1:42:50True or false?
1:42:53Partly true.
1:42:54Oh, good. Okay, partly. So, I can just
1:42:56pop that on night mode and dark mode and
1:42:58then I can carry on using my iPad.
1:43:00Partly true.
1:43:02So, it turns out that the blue light
1:43:04from screens does have an impact on
1:43:07sleep. There's a great study done by
1:43:08Harvard Medical School by some
1:43:10colleagues there. And they showed that
1:43:12reading for an hour on an iPad just
1:43:15before bed relative to just reading a
1:43:17book in dim light, firstly, it delayed
1:43:20the time with which people fell asleep.
1:43:22So, it took them a lot longer to fall
1:43:24asleep. Second, it reduced the total
1:43:26amount of sleep that they had. Third, it
1:43:29decreased a sleep-related hormone called
1:43:31melatonin. It delayed the release of
1:43:33that melatonin and it reduced the amount
1:43:35of melatonin. And finally, it reduced
1:43:37the amount of rapid eye movement sleep.
1:43:40So, it had
1:43:40Significantly.
1:43:41Significantly.
1:43:42point, how how significantly?
1:43:43So, it delayed the release by about
1:43:45somewhere between 90 minutes to 2 hours
1:43:48across the individuals. So, in other
1:43:49words, your brain wasn't So, what
1:43:51melatonin does, it's a it's called the
1:43:54hormone of darkness or the vampire
1:43:55hormone just because not
1:43:58cuz it makes you want to bite into
1:43:59people's necks, but because it signals
1:44:02to your brain that it's night time, that
1:44:04it's darkness.
1:44:05And so, your brain needs the signal of
1:44:07melatonin for it to understand when is
1:44:10it dark. In other words, it needs to
1:44:11understand by way of melatonin when it
1:44:14is time to fall asleep.
1:44:16And when you're bathed in electric light
1:44:18at night, and especially when you're
1:44:19getting blue light from these devices,
1:44:21your brain is fooled into thinking it's
1:44:23still daytime. And when there is light
1:44:26emitting through your retina, coming
1:44:28into your brain, it signals to a part of
1:44:30your brain to hit the brakes on
1:44:33melatonin, and your brain will not
1:44:35release melatonin. So, what was
1:44:36happening with this iPad reading is that
1:44:38you were artificially telling the brain
1:44:40it's still daytime, and the brakes on
1:44:43melatonin was still shut on. And so,
1:44:45melatonin was not starting to be
1:44:47released until much later.
1:44:50And what was it also interesting about
1:44:51this study, by the way, is that when
1:44:52they stopped the iPad reading, the sleep
1:44:54disrupted pattern continued for several
1:44:57days later. In other words, it was
1:44:58almost like a drug that it had a wash
1:45:00out period, that it was a blast radius
1:45:02to it.
1:45:03Now, there's been some great work by a
1:45:06wonderful sleep scientist in Australia,
1:45:08Michael Gradisar, and he has added to
1:45:11this story, and he said it's not just
1:45:14the blue light. These devices, the
1:45:16principal function of these devices is
1:45:19that they are attention capture devices.
1:45:21Just like you said, "I'm just going to
1:45:22have a wee little Tik Tok before bed."
1:45:25They are in the attention economy.
1:45:29And all they care about is capturing
1:45:31your attention for a current currency,
1:45:33and they make a lot of money from it.
1:45:35What that attention does is that it
1:45:37stimulates your brain. And when your
1:45:39brain is stimulated, it's very difficult
1:45:41for you to fall asleep, and it creates
1:45:43what we call sleep procrastination.
1:45:45Where you're lying in bed, and you could
1:45:47be perfectly sleepy, and you could fall
1:45:49asleep right now.
1:45:51But then you sort of check social media,
1:45:53and you think, "Oh, I'll just shoot that
1:45:54last email." And then I'll order that
1:45:56last thing on sort of, you know, Amazon.
1:45:59Uh and then you get a text back from
1:46:00your friend, and you start texting them.
1:46:02And and then you look up, and it's now
1:46:04an hour later, and you're an hour
1:46:06deficient on sleep. So, it's the
1:46:08activation of your cerebral cortex by
1:46:11these devices that is perhaps the more
1:46:13harmful aspect of them regarding your
1:46:16sleep.
1:46:17Now,
1:46:18here again, I don't want to be
1:46:20finger-wagging. You know, the genie of
1:46:22technology is out the bottle, and it's
1:46:24not going back in anytime soon. There's
1:46:26nothing that I'm going to say as a sleep
1:46:28researcher that's going to change that.
1:46:30I don't take my phone into my bedroom.
1:46:33I put my phone uh out in the kitchen. I
1:46:36don't uh see it until morning. But lots
1:46:38of people do, and fair enough. But
1:46:41there's another rule uh that I've stolen
1:46:43from another friend uh called Michael
1:46:45Grandner, who's uh here in America at
1:46:47the university
1:46:48um of uh Tucson in Arizona. He has this
1:46:51great rule regarding technology, and
1:46:53it's the following, that if you really
1:46:55must take your phone into your bedroom,
1:46:57you can only use it
1:47:00standing up.
1:47:02And what you'll find is that after about
1:47:046 or 7 minutes standing up, you think,
1:47:07"Ah, I'm just going to I'm just going to
1:47:08sit down on the bed." And at that point,
1:47:10as soon as your backside hits the bed,
1:47:11you're done. You've got to put the phone
1:47:13away. I think it's a great rule of thumb
1:47:14if uh if you need to take technology in
1:47:16the bedroom. Um
1:47:17I'm going to apply that. The other thing
1:47:19I wanted to ask was about sleep and
1:47:21weight loss.
1:47:23Had a lot of health experts on this
1:47:24podcast recently, but none of them have
1:47:26really talked to me about the role that
1:47:28sleep or sleep deprivation plays in
1:47:32weight.
1:47:33Is there a relationship?
1:47:35It's probably one of the most
1:47:37well-defined relationships that we know
1:47:40in all of sleep science.
1:47:42And it is at least a three-part story.
1:47:46So, the first emerging evidence came in
1:47:49terms of um hormones.
1:47:51So, there are what we call
1:47:53appetite-regulating hormones, and the
1:47:55two principal ones of concern here are
1:47:57something called leptin and ghrelin.
1:48:00Now, leptin, when it's released, will
1:48:03signal to your brain that you're
1:48:05satisfied with your food, you are
1:48:07satiated, and you are no longer hungry.
1:48:11Ghrelin does the opposite. When ghrelin
1:48:14is released, it says, "No, you're not
1:48:16satisfied with your food. You are not
1:48:19full. You still want to eat more. You
1:48:21are still hungry."
1:48:23And some of the first studies they
1:48:24started to do uh just limit people,
1:48:27restrict people's sleep to 6 hours or 5
1:48:29hours or 4 hours, and what they found
1:48:32was that um there was
1:48:34firstly, that signal leptin that says,
1:48:37"No, you're satisfied with your food.
1:48:39You don't want to eat any more. You're
1:48:40full."
1:48:42That signal of fullness, satiation, was
1:48:45decreased by 18%.
1:48:48If that wasn't bad enough, ghrelin,
1:48:50which is the hunger hormone, that leaped
1:48:53up by 28%.
1:48:58Overall hunger levels rose by about uh
1:49:0126%.
1:49:03So, firstly, you are It's almost like
1:49:06double jeopardy that you are getting
1:49:08punished twice for the same crime of not
1:49:11sleeping enough. Once by losing the
1:49:13signal of, "I'm full.
1:49:16I I don't want to eat any more. And once
1:49:18again, for the no, I'm much more hungry
1:49:21and I'm just going to overeat, which is
1:49:23ghrelin.
1:49:25So, what that produces is a profile of
1:49:29increased eating. So, on average,
1:49:31underslept individuals started to eat in
1:49:33those studies about 3 to 400
1:49:37extra calories at each sit at each
1:49:40sitting by way of insufficient sleep.
1:49:44Then, what they discovered is that it's
1:49:46not just
1:49:47that you want to eat more, it's what it
1:49:49is that you have a craving for when you
1:49:51are underslept.
1:49:53And this is the problem. What they found
1:49:55is that when you are underslept, you eat
1:49:57more of everything, but you especially
1:49:59eat more of these heavy-hitting starchy
1:50:02carbohydrates, bread, pasta, pizza.
1:50:06The The next thing that you started to
1:50:08eat have a preference for was simple
1:50:10sugary foods, sweets and chocolate. And
1:50:13then finally, you started to crave very
1:50:15salty food. And high sodium food intake
1:50:19will increase your blood pressure.
1:50:22So, that was the first of the the three
1:50:24mechanisms. Then, we did a study where
1:50:27we said, perhaps it's not just the
1:50:28circulating hormones in the body, the
1:50:30brain is the ultimate arbiter of your
1:50:34food decisions. So, what's going on in
1:50:36the brain? So, we took a group of
1:50:37perfectly healthy individuals and we put
1:50:39them through the experiment twice, once
1:50:41when they'd had a full 8 hours of sleep
1:50:43and once when we deprived them of
1:50:45And then the next day, we placed them
1:50:46inside an MRI scanner and we showed them
1:50:49images of lots of different foods that
1:50:51range from being sort of, you know, very
1:50:53healthy to being very unhealthy and sort
1:50:56of ice cream and, you know, chocolate
1:50:59and pizza and things to leafy salads and
1:51:02nuts and greens and vegetables.
1:51:05And we asked them to rate how much they
1:51:07wanted that food for each item. Now, we
1:51:10we something a bit sort of dastardly to
1:51:12make it more ecologically correct so
1:51:15that they weren't just saying, "Okay,
1:51:16they probably think I should probably
1:51:17say that's healthy." We said, "We're
1:51:19going to randomly select one of these
1:51:21images, these food images that you see,
1:51:23and after you get out the brain scanner,
1:51:25we're going to give you that food, and
1:51:26we're going to politely ask you to eat
1:51:27it all."
1:51:28So, it made it a bit more realistic so
1:51:30that choices were more, you know, as
1:51:32much as that we could.
1:51:33So, what we found is that when they were
1:51:35sleep deprived, the deep hedonic centers
1:51:39of the emotional centers of the brain,
1:51:42these desire centers, these reward
1:51:44centers,
1:51:45uh they ramped up in their activity in
1:51:47response to these highly desirable,
1:51:49highly unhealthy foods.
1:51:52So, these more basic sort of, you know,
1:51:54guttural parts of the brain, as it were,
1:51:57um these reward centers were lighting up
1:52:00much more strongly when you're sleep
1:52:01deprived. Worse still, the impulse
1:52:04control regions in the front of the
1:52:06brain, what we call the prefrontal
1:52:07cortex, they were shut down. They were
1:52:09taken offline.
1:52:11So, as a consequence, you lost your
1:52:12impulse control, and that's why you
1:52:15start to then say, you know, when I'm
1:52:16sleep deprived at the food sort of
1:52:19buffet,
1:52:20I'm not I'm not going to do salad. I'm
1:52:22just going to
1:52:23that pizza looks awful good, or that
1:52:25pasta with the cream I'm just going to
1:52:27go into that all go. So,
1:52:30so you're it's what we call a pattern in
1:52:32terms of brain activity uh in
1:52:34neuroscience of hedonic eating that your
1:52:37brain goes into this hedonic desire
1:52:39profile. So, now we understood it's not
1:52:42just hormones in the body, it's also
1:52:44changes in the brain.
1:52:45Then came the finding that there's
1:52:47another chemical in the body that's
1:52:49responsible.
1:52:51And this comes on to cannabis.
1:52:55When people um
1:52:58uh when people when people that you may
1:53:00know have smoked uh cannabis, they'll
1:53:02often say, "I get
1:53:04viciously hungry. I get the munchies. I
1:53:06get really hungry. That's no coincidence
1:53:08because cannabis will stimulate
1:53:11appetite. Now, we all have naturally
1:53:14occurring cannabis compounds in our
1:53:17brain and our bodies. They are called
1:53:20endocannabinoids.
1:53:22Endo meaning comes from inside us.
1:53:24Um whereas the cannabis that comes
1:53:27externally when you sort of smoke it or
1:53:29um take edibles.
1:53:31So,
1:53:33endocannabinoids do many things for the
1:53:35brain and the body, but one of the
1:53:36things that they do is control your
1:53:38appetite and your hunger. And what we
1:53:40found is that when you sleep deprived
1:53:42individuals, these naturally occurring
1:53:44endocannabinoids rocketed up by over
1:53:4720%.
1:53:49Cranking up people's appetite.
1:53:51Mhm.
1:53:52And so,
1:53:54these three ways lead you to start
1:53:56packing on, you know, when insufficient
1:53:59sleep is occurring, when sleep gets
1:54:00short, your waistline typically starts
1:54:03to expand.
1:54:04And we now understand the reasons. If
1:54:06that wasn't bad enough,
1:54:09It is bad enough.
1:54:09The final Yeah, I know. Yeah. Can you
1:54:11just stop, Matthew? Honestly, I really
1:54:13uh the the last thing that we discovered
1:54:15is that
1:54:17let's say that you're trying to be
1:54:18really careful and you're trying to diet
1:54:20and you're trying to lose weight.
1:54:22If you're not getting sufficient sleep,
1:54:25then 60% of all of the weight that you
1:54:28lose will come from lean muscle mass.
1:54:32Oh god, no.
1:54:33And not fat.
1:54:34Not the muscle.
1:54:35I know exactly. So, in other words, when
1:54:37you are dieting but you are under-slept,
1:54:40you lose what you want to keep, which is
1:54:42muscle,
1:54:44and you keep what you want to lose,
1:54:46which is fat.
1:54:48So, again, it's
1:54:50I'm sold.
1:54:51not an ideal situation.
1:54:53My last question for you, in fact, was
1:54:55of all the subject matter we've talked
1:54:57about,
1:54:58what is the most interesting thing we've
1:54:59missed in your view? The thing that you
1:55:02think is most pertinent or interesting
1:55:03or significant or that perks people up
1:55:06or sits them on the end of their chair
1:55:07when you discuss it?
1:55:11I think the only other area that
1:55:14fascinates people even more than sleep
1:55:18is dreaming.
1:55:19Mhm.
1:55:21So, dreaming above and beyond the stage
1:55:24of which it comes from, which is
1:55:25principally called rapid eye movement
1:55:27sleep or dream sleep,
1:55:28REM sleep provides a set of
1:55:30physiological and
1:55:32benefits, but dreaming we've now
1:55:34discovered, even above and beyond that,
1:55:37provides benefits. And it provides at
1:55:39least two benefits. The first is
1:55:41creativity. I was telling you that
1:55:42during deep sleep you cement individual
1:55:44memories. You grab memories and you
1:55:47shift them from a short-term storage
1:55:48reservoir to a long-term storage
1:55:50reservoir and you strengthen the circuit
1:55:52of those memories. So, you future-proof
1:55:54information. But, that's individual
1:55:56memories. What we discovered is that
1:55:58sleep is much more intelligent than you
1:56:00ever thought possible. That it's during
1:56:03REM sleep, and particularly during
1:56:04dreaming, that we take all of the
1:56:06individual pieces of information that
1:56:08we've been learning and we start
1:56:10interconnecting them and associating
1:56:12them with all of our back catalog of
1:56:15stored information.
1:56:17And so, what dream sleep, one of the
1:56:18functions of dream sleep, is to
1:56:21cross-link
1:56:22and associate new memories together. So,
1:56:24you wake up the next day having after
1:56:27dream sleep with a revised mind web of
1:56:31associations and those are capable of
1:56:33divining solutions to previously
1:56:35impenetrable problems.
1:56:37So, think of dreaming as
1:56:40it's almost like informational alchemy.
1:56:43That you start to fuse things together
1:56:45that shouldn't normally go together.
1:56:47But, when they do, they cause marked
1:56:49advances in your thinking, in your
1:56:51productivity, in your ingenuity.
1:56:53And in that way, you go to sleep with
1:56:56the pieces of the jigsaw,
1:56:58but you wake up with the puzzle
1:57:00complete. And I would argue that that's
1:57:02the difference between knowledge, which
1:57:04is remembering the individual pieces,
1:57:07and wisdom,
1:57:08which is knowing what it all means when
1:57:11you fit them together. That's one of the
1:57:13functions of dreaming. It's the reason,
1:57:15by the way, that you've never been told
1:57:16to stay awake on a problem.
1:57:18Yeah.
1:57:19Um
1:57:20The other function of dreaming that we
1:57:23know of is that dreaming provides a form
1:57:25of emotional first aid.
1:57:28That we've We've done a lot of work and
1:57:30we came up with a a theory that was
1:57:31called dreaming as overnight therapy.
1:57:35And what we've discovered is that when
1:57:37we go into dream sleep, particularly
1:57:39based on its neurochemical profile and
1:57:40its physiological anatomy of the brain,
1:57:43um the dreaming brain will take
1:57:46difficult, painful experiences,
1:57:47sometimes traumatic experiences,
1:57:50and it will essentially strip away the
1:57:52bitter emotional rind from the
1:57:55informational orange. So, let's take a
1:57:57step back. What makes a memory
1:57:58emotional? What makes a memory emotional
1:58:00is that at the time of the experience,
1:58:03that experience triggered a strong
1:58:05visceral reaction. And that visceral
1:58:07reaction is useful to the brain, and it
1:58:09wraps that experience in this blanket of
1:58:12what we call emotion. It red flags it
1:58:14and prioritizes it in the brain. So, now
1:58:16you've created a memory of an emotional
1:58:18event. In other words, you've created an
1:58:20emotional memory.
1:58:22But what dream sleep does is then it
1:58:25takes that useful emotional memory and
1:58:28it will detox the emotion from the
1:58:30memory. It strips the bitter emotional
1:58:33rind from the informational orange.
1:58:35Mhm.
1:58:36It's almost And that's why we called it
1:58:39overnight therapy. So, that the next day
1:58:41you come back, and now you feel better
1:58:43about those experiences.
1:58:45So, you have a memory of an emotional
1:58:49event, but it's no longer emotional
1:58:51itself. You don't regurgitate that same
1:58:53visceral reaction that you had at the
1:58:55time of learning. So, the brain has done
1:58:58this elegant trick of stripping the
1:59:00emotion from the memory.
1:59:02So, it's That's the That's the the
1:59:05second benefit um is that it provides
1:59:08It's not time that heals all wounds. It
1:59:11is time during sleep and particularly
1:59:13during dream sleep that provides
1:59:15emotional convalescence.
1:59:17It's funny because there's a the
1:59:18stereotype that we should never go to
1:59:19bed angry at each other.
1:59:21You will wake up far less angry as a
1:59:24consequence.
1:59:26Matt, we have a closing tradition on
1:59:27this podcast where the last guest asks a
1:59:29question for the next guest not knowing
1:59:30who they're going to ask it for.
1:59:32Um the question that's been left for you
1:59:33from our previous guest, obviously they
1:59:35didn't know who they're leaving it for,
1:59:36but uh it's a very I love these
1:59:37questions when they're challenging.
1:59:38Um
1:59:40what is the biggest way in which you are
1:59:41a contradiction?
1:59:46Gosh, I'm a contradiction
1:59:48in so many ways. I think
1:59:52I'm a contradiction in the sense that
1:59:54within my profession and with this field
1:59:57of sleep, I feel very comfortable. I'm
2:00:00reticent to say confident, but I am very
2:00:03comfortable to get on stage, you know,
2:00:05give a TED Talk in front of couple of
2:00:07thousand people and my heart rate will
2:00:09be very stable. I probably
2:00:14I probably don't feel I I feel more
2:00:17myself on stage alone in front of
2:00:20thousands of people than I do at any
2:00:22other time in my life. That's where I
2:00:24feel most myself.
2:00:26But yet I'm a contradiction because off
2:00:30stage
2:00:31I'm very insecure.
2:00:34I'm very much an introvert. I'm very
2:00:37shy.
2:00:38Um I don't like being the focus of
2:00:41attention.
2:00:42And so, those two things I've often
2:00:44wrestled with, but the more people I've
2:00:46spoken to sort of now being out in the
2:00:48public sphere and sort of
2:00:50sort of being more in the sort of public
2:00:51intellectual realm, you start to meet,
2:00:53you know, very famous people, and you
2:00:57meet, you know, musicians, and
2:01:00and what you learn is that they're very
2:01:01similar, that they say that they become
2:01:03this version of themselves on stage, and
2:01:06then when they're off stage, they are a
2:01:08radically different person. But I am
2:01:10such a contradiction in that sense. I
2:01:12feel very comfortable and very secure on
2:01:16stage in front of thousands people. And
2:01:19for many people, public speaking is one
2:01:21of the most anxiogenic things you can
2:01:24ask anyone to do. But for me,
2:01:26heart rate is probably in the, you know,
2:01:29mid-40s.
2:01:31Uh, very relaxing for me. But then, put
2:01:34me in a room, you know, a small room of
2:01:36a couple of people, my heart rate's
2:01:37probably through the roof, and I've
2:01:38become very introverted. So, I'm a
2:01:39contradiction in that sense.
2:01:41Um,
2:01:43yeah.
2:01:45Matthew, thank you. Thank you for for
2:01:47making the time today. I've I've I've
2:01:49wanted to speak to you for many, many
2:01:50years, and you absolutely never
2:01:52disappoint anybody. So, you're
2:01:54That's very kind of you to say.
2:01:55It's exceptionally important work, and
2:01:56as you said at the start of this
2:01:57conversation, we often neglect the
2:02:00medicinal properties of a great night's
2:02:02sleep over things like diet and medicine
2:02:04or exercise, whatever whatever else it
2:02:06is. But your your voice and the the the
2:02:08passion that sits behind it has led a a
2:02:11charge in society, which is waking us
2:02:13up, no pun intended,
2:02:15to the um the virtues and the power and
2:02:18the importance of having a great night's
2:02:20sleep. But in a nice way, in a way that
2:02:22I find it really empowering and
2:02:23actionable, and that's the most
2:02:24important thing. So, thank you for that,
2:02:25Matthew.
2:02:26Thank you, and thank you for saying that
2:02:27last part especially. I I don't think I
2:02:30can um
2:02:31lay claim to that sort of uh early on. I
2:02:33think I'm doing much better as uh much
2:02:35better. I'm doing a little bit better as
2:02:37a public communicator, and being less
2:02:39puritanical and dictatorial in my sleep
2:02:41message. I think I did a terrible job
2:02:43coming out. I'm learning and I'm being
2:02:45more sensitive, but I'm always lovely to
2:02:48hear feedback from folks about what I'm
2:02:49not doing well cuz I would love to do
2:02:51this better and better if I can. Um but
2:02:54thank you for saying those kind words
2:02:55and thank you again for having me on,
2:02:57giving me this opportunity to speak. I
2:02:59now will anoint you as a sleep
2:03:01ambassador from this point forward, so
2:03:04thank you so much again, Stephen. I
2:03:06really appreciate you.
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2:04:23You know, I never really usually pick
2:04:24the chocolate flavored Huel. My favorite
2:04:26are the banana flavor. I love the salted
2:04:29caramel flavor. But recently, I think I
2:04:33in part blame Jack in my team, who's
2:04:35obsessed with the chocolate flavor Huel.
2:04:37I've started drinking the chocolate
2:04:38flavor Huel for the first time and I
2:04:39absolutely love them. My life means that
2:04:42I sometimes disregard my diet and it's
2:04:44funny, that's part of the reason why
2:04:45I've had a lot of guests on this podcast
2:04:47recently that talk about diet and health
2:04:48and and those kinds of things because I
2:04:50am trying to make an active effort to be
2:04:52more healthy, to lose a little bit of
2:04:53weight as well, but to be more healthy.
2:04:55And the role that Huel plays in my life
2:04:57is it means that in those moments where
2:04:58sometimes I might reach for
2:05:01you know,
2:05:02junk foods,
2:05:04having an option that is nutritionally
2:05:05complete, that is high in fiber, that is
2:05:07incredibly high in protein, that has all
2:05:09the vitamins and minerals that my body
2:05:10needs, within arms reach, that I can
2:05:13consume on the go, is where Huel has
2:05:15been a game changer for me.

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