If You IGNORE These 5 Bedtime Rules, You’ll DESTROY Your Sleep

0:00 My question is what are the things that in the modern society are standing in the way of sleep? We've touched on some of them loosely, but some of the like big obvious things, the things that you would suggest doing, very actionable things we could do straight away to improve our chances of having that healthy um deep sleep that we need to be um optimal in every regard of our health and performance. There's probably I think five standard tips what we call sort of sleep hygiene that you can do and then I'll come on to maybe just some unconventional tips uh that we've sort of touched on and we've spoken about many of these. The first thing I would recommend people to do and this is why when some people say oh what about this new sleep supplement or you know it's it's 40 quid for this bottle of these sleep the new sleep natural

0:46 medications I'm going to give it a try. I would say try these tried andrue things first before you spend your money on supplements. The first thing is regularity. Go to bed at the same time and wake up at the same time. No matter whether it's the weekday or the weekend, your brain expects regularity. It thrives best under conditions of regularity. When you give it regularity, you can improve the quantity and the quantity of your sleep. The second thing is get some darkness at night. As I said, we don't get enough darkness in the modern world. And so the trick I would offer, and I don't use it, I don't like the word hack, but the sort of suggestion would be in the last hour before bed, try this experiment for everyone listening for the next week,

1:33 dim down half of the lights or switch off half of the lights or even a 3/4 of the lights in your home in the last hour before bed. All of the lights in every room. in all of the rooms, you know, switch off almost all of the light. Now, I'm not suggesting be unsafe and walk around in the darkness in the last hour. That's not what I want to say. Just dimmed down, you know, switch off half of the lights. You will be surprised at how sleepy that darkness will make you feel. And it's also an incredible behavioral trigger to signal to your brain that it is time for sleep, that darkness is around me. That's the second tip is darkness. The third ti tip is temperature. Most people sleep in an

2:19 ambient bedroom temperature that is too high. And you need to aim for a bedroom temperature of about 18 18 1.5° C around about 65 to 68° F if I'm probably butchering the the mathematics there on that. But um you need to get cool. Now you can wear thick socks. You can have a hot water bottle. That's fine. But the ambient needs to be cold because you need to drop your core body temperature and your brain temperature by about one degree Celsius to fall asleep and stay asleep. And it's the reason that you will always find it easier to fall asleep in a room that's too cold than too hot. So make your bedroom cold, make it dark like a cave. The the fourth question would be sort of what we've or

3:06 fourth suggestion would be walk it out. And we've spoken about this the 30 minute rule you know get up do something different or meditate you know don't lie in bed awake for too long then the final two things we've spoken about well we've spoken about caffeine we haven't spoken about alcohol but let me just say as the kind of headline of it alcohol is not a sleep aid many people use it as a sleep aid it is not your friend alcohol again is a seditive so it knocks you out the second is that it fragments your sleep so you wake up your sleep is littered with all of these small awakenings. Most of them you don't remember cuz they're too brief, but it makes for miserable, lousy quality sleep. And the final thing is that alcohol is very good at blocking your REM sleep or your dream sleep, which we know is critical for many other

3:52 functions as well. So alcohol is not your friend. That's the sort of the final tip. Again, you know, just every if you're with friends, have a glass of red wine. Just know, okay, my sleep's not going to be great. That's right. And it's not, you know, I'm not Yeah, I'm once it's just, you know, live life, too. I'm not saying that. I I was I was thinking there about the other sort of behavioral things that we do that harm our sleep as well. We talked about coffee earlier on, avoiding that. It's weird that people drink it after dessert in the evenings. So, never understood that. Guess that's an old tradition. Um, but the other thing obviously that the modern generation are even more susceptible to is to have a quick Tik Tok, look at the social media account or something. Now, I thought, you know,

4:37 there's a lot of different products out there that are trying to help with the the the light that comes from these screens that I think is the cause of what's keeping us awake. But there's this little button called dark mode on my iPad. Oh, there's also one called night shift. So, if I just pop that on, Bob's your uncle. And this and I can crack on with my screen time. True or false? Partly true. Oh, good. Okay. Partly. So I can just pop that on night mode and dark mode and then I can carry on using my iPad. Partly true. So it turns out that the blue light from screens does have an impact on sleep. So there's a great study done by Harvard Medical School by some colleagues there and they showed that reading for an hour on an iPad just before bed relative to just reading a

5:24 book in dim light. Firstly, it delayed the time with which people fell asleep. So it took them a lot longer to fall asleep. Second, it reduced the total amount of sleep that they had. Third, it decreased a sleepreated hormone called melatonin. It delayed the release of that melatonin and it reduced the amount of melatonin. And finally, it reduced the amount of rapid eye movement sleep. So, it had significantly significantly the melatonin point. How significantly? So, it delayed the release by about somewhere between 90 minutes to 2 hours across the individuals. So, in other words, your brain wasn't. So, what melatonin does, it's a it's called the hormone of darkness or the vampire hormone just because not be because it makes you want to bite into people's necks, but because it signals to your

6:09 brain that it's nighttime, that it's darkness. And so, your brain needs the signal of melatonin for it to understand when is it dark. In other words, it needs to understand by way of melatonin when it is time to fall asleep. And when you're bathed in electric light at night and especially when you're getting blue light from these devices, your brain is fooled into thinking it's still daytime. And when there is light emitting through your retina coming into your brain, it signals to a part of your brain to hit the brakes on melatonin. And your brain will not release melatonin. So what was happening with this iPad reading is that you were artificially telling the brain it's still daytime and the brakes on melatonin was still shut on. And so melatonin was not starting to be released until much

6:55 later. And what was also interesting about that study, by the way, is that when they stopped the iPad reading, the sleep disrupted pattern continued for several days later. In other words, it was almost like a drug that it had a wash out period that was a blast radius to it. Now there's been some great work by a wonderful sleep scientist in uh Australia uh Michael Gradazar and he has added to this story and he said it's not just the blue light these devices the principle function of these devices is that they are attention capture devices just like you said I'm just going to have a wee little Tik Tok before bed. They are in the attention economy and all they care about is capturing your attention for a current currency and they make a lot of money from it. What

7:43 that attention does is that it stimulates your brain. And when your brain is stimulated, it's very difficult for you to fall asleep. And it creates what we call sleep procrastination where you're lying in bed and you could be perfectly sleepy. And you could fall asleep right now. But then you sort of check social media and you think, "Oh, I'll just shoot that last email. Oh, then I'll order that last thing on sort of, you know, Amazon." Uh, and then you get a text back from your friend and you start texting them and and then you look up and it's now an hour later and you're an hour deficient on sleep. So, it's the activation of your cerebral cortex by these devices that is perhaps the more harmful aspect of them regarding your sleep. Now, here again, I don't want to be finger wagging. You know, the genie

8:29 of technology is out the bottle and it's not going back in anytime soon. There's nothing that I'm going to say as a sleep researcher that's going to change that. I don't take my phone into my bedroom. I put my phone uh out in the kitchen and I don't uh see it until morning. But lots of people do and fair enough. But there's another rule uh that I've stolen from another friend called Michael Grandner who's uh here in America at the University um of uh Tucson in Arizona. He has this great rule regarding technology and it's the following. That if you really must take your phone into your bedroom, you can only use it standing up. And what you'll find is that after about six or seven minutes standing up, you think, I'm just going

9:14 to I'm just going to sit down on the bed. And at that point, as soon as your backside hits the bed, you're done. You've got to put the phone away. I think it's a great rule of thumb if uh if you need to take technology in the bedroom. Um I'm going to apply that. The other thing I wanted to ask was about sleep and weight loss. Had a lot of health experts on this podcast recently, but none of them have really talked to me about the role that sleep or sleep deprivation plays in weight. Is there a relationship? It's probably one of the most welldefined relationships that we know in all of sleep science. And it is at least a threepart story. So the first emerging evidence came in terms of um hormones. So there are what we call appetite regulating

10:01 hormones and the two principal ones of concern here are something called leptin and ghrein. Now leptin when it's released will signal to your brain that you're satisfied with your food. You are satiated and you are no longer hungry. Grein does the opposite. When ghrelin is released, it says no, you're not satisfied with your food. You are not full. You still want to eat more. You are still hungry. And some of the first studies, they started to uh just limit people, restrict people's sleep to 6 hours or 5 hours or 4 hours. And what they found was that um there was firstly that signal leptin that says no, you're satisfied with your food. You

10:46 don't want to eat anymore. You're full. That signal of fullness, satiation, was decreased by 18%. If that wasn't bad enough, grein, which is the hunger hormone, that leapt up by 28%. Overall hunger levels rose by about uh 26%. So firstly, you are it's almost like double jeopardy that you are getting punished twice for the same crime of not sleeping enough. Once by losing the signal of I'm full. I I don't want to eat anymore. And once again for the no, I'm much more hungry and I'm just going to overeat, which is ghrein. So what that produces is a

11:35 profile of increased eating. So on average underslept individuals started to eat in those studies about 3 to 400 extra calories at each sit at each sitting by way of insufficient sleep. Then what they discovered is that it's not just that you want to eat more. It's what it is that you have a craving for when you are underslept. And this is the problem. What they found is that when you are underslept, you eat more of everything, but you especially eat more of these heavyhitting, stodgy carbohydrates, bread, pasta, pizza. The the next thing that you started to eat, have a preference for was simple sugary foods, sweets, and chocolate. And then finally, you started

12:21 to crave very salty food. And high sodium food intake will increase your blood pressure. So that was the first of the the three mechanisms. Then we did a study where we said perhaps it's not just the circulating hormones in the body. The brain is the ultimate arbiter of your food decisions. So what's going on in the brain? So we took a group of perfectly healthy individuals and we put them through the experiment twice. Once when they'd had a full 8 hours of sleep and once when we deprived them of sleep. And then the next day we placed them inside an MRI scanner and we showed them images of lots of different foods that range from being sort of, you know, very healthy to being very unhealthy and sort of ice cream and, you know, chocolate and pizza and things to leafy salads and

13:09 nuts and greens and vegetables. And we asked them to rate how much they wanted that food for each item. Now, we did something a bit sort of dastardly to make it more ecologically correct so that they weren't just saying, "Okay, they probably think I should probably say that's healthy." We said, "We're going to randomly select one of these images, these food images that you see, and after you get out the brain scanner, we're going to give you that food and we're going to politely ask you to eat it all." So, it made it a bit more realistic. So, the choices were more, you know, as much as that we could. So what we found is that when they were sleepdeprived, the deep hadonic centers, the emotional centers of the brain, these desire centers, these reward centers, um they ramped up in their activity in response to these highly

13:56 desirable, highly unhealthy foods. So these more basic sort of, you know, guttural parts of the brain as it were, um these reward centers were lighting up much more strongly when you were sleepd deprived. Worse still, the impulse control regions in the front of the brain, what we call the prefrontal cortex, they were shut down. They were taken offline. So, as a consequence, you lost your impulse control. And that's why you start to then say, you know, when I'm sleepd deprived at the food sort of buffet, I'm not I'm not going to do salad. I'm just going to that pizza looks awful good. Or that pasta with the cream, I'm just going to go into that. All go. So, so your it's what we call a pattern in terms of brain activity uh in

14:41 neuroscience of hydonic eating that your brain goes into this hadonic desire profile. So, now we understood it's not just hormones in the body, it's also changes in the brain. Then came the finding that there's another chemical in the body that's responsible. And this comes on to cannabis. When people um uh uh when people when people that you may know have smoked cannabis, they'll often say, "I get viciously hungry. I get the munchies. I get really hungry." That's no coincidence because cannabis will stimulate appetite. Now, we all have naturally occurring cannabis compounds in our brain and our bodies. They are

15:26 called endocinabonoids. Endo meaning comes from inside us. um whereas the cannabis that comes externally when you sort of smoke it or um take edibles. So endockinabonoids do many things for the brain and the body, but one of the things that they do is control your appetite and your hunger. And what we found is that when you sleepd deprived individuals, these naturally occurring endockinabonoids rocketed up by over 20%. Cranking up people's appetite. And so these three ways lead you to start packing on. You know, when insufficient sleep is occurring, when sleep gets short, your waistline typically starts to expand. And we now

16:12 understand the reasons. If that wasn't bad enough, it is bad enough. The find Yeah. Can you just stop, Matt, please? Honestly, I've really uh the the last thing that we discovered is that let's say that you're trying to be really careful and you're trying to diet and you're trying to lose weight. If you're not getting sufficient sleep, then 60% of all of the weight that you lose will come from lean muscle mass. Oh god. No. And not fat. Not the muscle. I know. Exactly. So in other words, when you are dieting but you are underslept, you lose what you want to keep, which is muscle, and you keep what you want to lose, which is fat. So again, it's I'm sold. Not an ideal

16:59 situation. My last question for you, in fact, was of all the subject matter we've talked about, what is the most interesting thing we've missed in your view? the thing that you think is most pertinent or interesting or significant or that perks people up or sits them on the end of their chair when you discuss it. I think the only other area that fascinates people even more than sleep is dreaming. So dreaming above and beyond the stage of which it comes from which is principally called rapid eye movement sleep or dream sleep. REM sleep provides a set of physiological and uh benefits but dreaming we've now discovered even above and beyond that provides benefits

17:45 and it provides at least two benefits. The first is creativity. I was telling you that during deep sleep you cement individual memories. You grab memories and you shift them from a short-term storage reservoir to a long-term storage reservoir and you strengthen the circuit of those memories. So you futureproof information. But that's individual memories. What we discovered is that sleep is much more intelligent than you ever thought possible. That it's during REM sleep and particularly during dreaming that we take all of the individual pieces of information that we've been learning and we start interconnecting them and associating them with all of our back catalog of stored information. And so what dream sleep, one of the functions of dream sleep is to cross-link and associate new

18:30 memories together. So you wake up the next day having after dream sleep with a revised mind web of associations and those are capable of diving solutions to previously impenetrable problems. So think of dreaming as it's almost likeformational alchemy that you start to fuse things together that shouldn't normally go together but when they do they cause marked advances in your thinking in your productivity in your ingenuity. And in that way, you go to sleep with the pieces of the jigsaw, but you wake up with the puzzle complete. And I would argue that that's the difference between knowledge, which is remembering the individual pieces, and wisdom, which is knowing what it all

19:17 means when you fit them together. That's one of the functions of dreaming. It's the reason, by the way, that you've never been told to stay awake on a problem. Yeah. Um the other function of dreaming uh that we know of is that dreaming provides a form of emotional first aid that we've we've done a lot of work and we came up with a a theory that was called uh dreaming as overnight therapy and what we've discovered is that when we go into dream sleep particularly based on its neurochemical profile and its physiological anatomy of the brain um the dreaming brain will take difficult painful experiences sometimes traumatic exper experiences and it will essentially strip away the bitter emotional rind from theformational

20:02 orange. So let's take a step back. What makes a memory emotional? What makes a memory emotional is that at the time of the experience that experience triggered a strong visceral reaction and that visceral reaction is useful to the brain and it wraps that experience in this blanket of what we call emotion. It red flags it and prioritizes it in the brain. So now you've created a a memory of an emotional event. In other words, you've created an emotional memory. But what dream sleep does is then it takes that useful emotional memory and it will detox the emotion from the memory. It strips the bitter emotional rind from the informationational orange. It's almost and that's why we called it overnight therapy. So that the next day

20:48 you come back and now you feel better about those experiences. So you have a memory of an emotional event but is no longer emotional itself. You don't regurgitate that same visceral reaction that you had at the time of learning. So the brain has done this elegant trick of stripping the emotion from the memory. So it's that's this that's this the second benefit um is that it provides it's not time that heals all wounds. It is time during sleep and particularly during dream sleep that provides emotional convolescence. It's funny because there's the stereotype that we should never go to bed angry at each other. You will wake up far less angry as a consequence. If you love the D CEO

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