The Science of Better Sleep & Health | Caroline Lustenberger (#15)
Episode Summary: Mastering the Science of Sleep
Caroline Lustenberger, a leading sleep researcher with a PhD in neuroscience from ETH Zurich, joins me to uncover the truths about sleep and its impact on our health and well-being. With her deep expertise, Caroline explores the science behind how and why we sleep, debunks common myths, and provides practical advice for improving sleep quality.
Expect to learn why the “8-hour rule” doesn’t apply to everyone, how modern habits like screen time and caffeine affect your sleep, and the role of light and temperature in creating the ideal sleep environment. Caroline also shares insights on the effectiveness of sleep supplements and trackers, managing early morning wake-ups, and her groundbreaking work with the Herencia initiative, which connects sleep research to Alzheimer’s prevention. This episode is packed with actionable tips to help you rest better and wake up refreshed.
About Caroline Lustenberger: Sleep Science Expert
Caroline Lustenberger holds a PhD in Neuroscience from ETH Zurich and has over 15 years of experience in sleep research. As a group leader at ETH Zurich, she focuses on the modulation of brain activity during sleep to promote recovery processes of the brain and body. Her innovative work includes developing non-invasive brain stimulation techniques and wearable devices to enhance sleep quality. Caroline is also a co-author of the book Dieses Buch ist zum Einschlafen, which aims to alleviate the pressure of achieving “perfect” sleep by providing a relaxed approach to sleep health.
Contact
https://www.linkedin.com/in/caroline-lustenberger-891493219/
More about the Herencia Initiative
Full Transcript
Mike: [00:00:00] What are some of the biggest misconceptions about sleep that you wish people understood better?
Caroline: Well, I would say there’s so many misconceptions still, unfortunately. Um, but today I want to focus on two that keep coming up in the media. Um, And they are oversimplified and frankly, also, I would say very misleading. The first one is, and here I really focus on adult sleep recommendations, is that everyone needs exactly eight hours of sleep.
Well, we are very individual and also sleep is very individual. And [00:01:00] so also here, it’s important to emphasize that not one size fits all. Saying that everyone needs eight hours of sleep is like saying everyone needs the same shoe size. And of course, there is an average, right? It’s eight hours, and there is a range where most people fit in, which is around seven to nine hours.
But there is still a significant number of people that need less than seven hours or more than nine hours. And This is, of course, very important to understand, because it can also be problematic if you try to put everyone in the same box, um, you might even increase the chance that there are sleep problems.
And I’ll give you very specific examples for that. So let’s assume someone needs just a, a six hours feeling refreshed, you know, after six hours and very productive during the day, and suddenly they have the feeling they also need eight hours. What happens is they try to prolong their time in bed. And a colleague that I [00:02:00] know, he told me once you have to think about sleep like a pizza dough.
So if you, if you drag it too much, there will be holes in it. Same will happen to this person. So with time, the next following sleep periods will be, you know, more fragmented, less consolidated. And you might even start having people with sleep problems that did not have problems before. Then we have the other example, right?
Someone may be needing 10 hours of sleep, but then thinks, okay, eight hours is enough, but doing so they realize they’re not refreshed during the day. So I always tell people, um, really try to figure out yourself, how many hours you need, and a good feeling for that is. What is the number of hours you need to really feel refreshed and productive during the day?
If you reflect on that and realize, always, almost, like, constantly are falling asleep and there is a quiet, you know, period when you’re sitting in a meeting or in a presentation or so, you probably do [00:03:00] not get enough sleep, right? So you really have to try there to basically maybe give a bit more sleep. Um, at the same time, if you really try to prolong your sleep, but realize that you still do not feel refreshed and you have problems during the day, um, without being able to somehow get a restorative sleep, it might also be time for you to talk to experts.
And there are great people. Places out there here in Switzerland where you can consult if you have the feeling you might have a sleep problem or a sleep disorder. Then a second misconception that keeps coming up is that sleep before midnight is supposedly the healthiest sleep. And I’m not sure why this is always coming up.
I just recently read it again in a newspaper. Um, I think it’s somehow rooted in the belief that there is a universal ideal bedtime. I But it’s not [00:04:00] true, right? That our body is not interested about the clock time per se. Our body is more interested about the inner clock. And that’s again very individual.
Some people, they are naturally early risers. They love to go to bed early and they are fresh and awake at five or six in the morning. But others are like these late types where It’s for them, like unbelievable to go to bed before one at night, but then they also might need to sleep until 10 to not feel like a zombie in the morning.
And so I think that sleep is only restorative before midnight is actually not true. Every sleep in the first few hours, independent when you started is just the sleep period that has most deep sleep. And I think that’s why also the notion comes from that the early part of sleep is the most restorative one.
Mike: Does the. The notion of sleeping before midnight come from the circadian rhythm [00:05:00] of, six till six, um, every person has a clock that is aligned with the sunrise, sunset, Is that where it’s coming from? To do with the, to do with the sunlight?
Caroline: I can actually not really tell that it’s coming from that.
Um, first of all, it’s a misconception that with, um, sunrise and sunset, everyone sets the clock the same. So because you have different chronotypes, it means also the way your body translate the light signal and how fast it goes that your body thinks it’s your inner night. It’s different for some, it’s a bit later.
And for some, it’s a bit earlier. I think it’s also related to the way how society works. I mean, at the moment , society really favors early types, right? So a lot of jobs, also school start times are rather early. And there’s also a bit this misconception that if you are a person that gets up earlier, you’re a more productive person and more successful person in life.
But I think it has to do that. Of course, the schedules of society also favoring this [00:06:00] kind of chronotype, right?
Mike: That’s interesting. Yeah. My, my wife is a. I would call her the creative type. So she usually goes to bed three, three hours after I do. Um, and also sleeps in and she is equally as functional as I am.
Just different times of the day.
Caroline: Exactly. So if you give them the time to sleep in, they are as productive. They might just have their best productivity later than the ones that rise earlier.
Mike: What about people who at least claim that they only need four or five hours of sleep? Is there a minimum threshold which you think everybody needs and anybody under that really should reassess the amount of sleep they’re getting?
Caroline: Let me start with a balanced perspective to this question. So first of all, yes, there are indeed a very small fraction of people that need less than six hours of sleep. And that’s a very small are generally [00:07:00] driving on these, um, four to five hours and that actually also don’t have any negative effects.
These individuals are rare and it’s really an exception, not a rule. So if you know a lot of people around you that claim they need four to five hours of sleep, I will be a bit suspicious. I know
Mike: one, I know one very special person and he’s probably listening to this as well. He knows who he is. Oh,
Caroline: that’s really funny.
Yeah, because I mean, of course, there are very, um, seldomly people that have that. But I think a good sign of self deception is that of course, when you have time to relax during the day, let’s say you are listening. to a presentation or in a meeting or in a dark room or sitting in a train and it’s very hard for you to not doze off or you actually frequently fall quickly asleep.
It is really a sign that you’re not well rested and you for sure need more sleep. Also, if you always have to sleep in during the weekend, you know, if you sleep many more hours during the [00:08:00] weekend, during the week, this is also a sign you don’t get enough sleep. And I think I want to emphasize here again, the problem of society.
I think it’s a bit less of a problem now, but it was for sure before that basically cutting corners on sleep was some kind of a badge of honor, right? That you are a very successful, that you basically favor productivity over sleep. And I just, it is just stupid.
Mike: Yeah,
Caroline: exactly. It was the notion, right? And I think one problem there is really that you cannot, um, basically.
Discuss with sleep how much you want to have it, right? You need a certain amount of sleep and this is non negotiable What happens if you constantly? To sleep deprive or sleep restrict yourself is that first of all, it will have consequences on your performance. So you do actually the [00:09:00] opposite you want, right?
You will get less effective. You will have bad decision making, your executive functions are worse. Your mood is worse, but over longer time, this also has, um, clear, gives clear problems on, on health related aspects. So I always say, I mean, really get the sleep amount you need, and that’s the best you can do for yourself and your productivity.
And here, I, I want to give a very funny example from Bill Gates. I read a year ago, an interview with him, and he was one of these people who really thought that, you know, sleep is a lazy habit. And he was in this interview about saying, you know, they even competed against, like with colleagues that if you don’t get, Yes.
If you just sleep like four hours, this is really cool. And sometimes you don’t sleep at all. This really shows that you’re committed to your work and so on. Try to, to beat each other by having less sleep. And he’s basically minds [00:10:00] shifted completely when his father was diagnosed with Alzheimer’s disease because he was starting to read up on the disease itself.
And he realized that brain health is very strongly related to sleep and the amount of sleep. And that’s, A very stupid thing you can do is basically to cut sleep because it can even be involved in the pathology and the cause for Alzheimer’s disease. So I think this was the moment for him to realize, well, I shouldn’t have done that and now I really prioritize it in my life.
Mike: How much of when I sleep and how long I sleep is determined by society? So if I, if we removed all clocks, all screens, all electricity, all reasons to get up in the morning, and I was just a man in a cave, what would my sleeping pattern, how different would my sleeping pattern be from what it is today?
Caroline: I think if we stripped away all constraints of [00:11:00] modern life, our sleep timing, but also the number of hours we get will be much more aligned to our biological need.
And I think it will especially, specifically affect people who are very much misaligned, um, by society if they’re in their bedtime and ideal rise time, right? We know there are individual variations and society maybe favors rather the early types. So if you are completely shifting yourself because you want to make sure that you are ready at eight in the morning for the meeting, but you’re actually a person who sleeps preferably at one or two in the morning, and then because of that, only get a few hours of sleep.
You will basically are really working against your inner clock and your need for sleep. It’s also called social jet lag. So without even moving over time zones, you have kind of a misalignment between your inner clock and potentially you do during the day because of society. [00:12:00] So it will for sure help to basically get back to your natural rhythm.
What I always say is we cannot, of course, um, strip away the things, right? It’s part of our life. But what we can start trying to do is better understand what is our biological clock? When is, what is our chronotype? When do we function best? When is our ideal bedtime? And then also try as good as possible to move around the social aspects as you can.
For instance, you, one example is depending on your job, you could talk to your boss and see whether it’s possible to maybe start a bit later, but then also stay longer. Right. To say basically as a justification that it’s just when you are more productive and you will get more things done. Right. So that could be an approach.
Mike: How do our demands for sleep change as we age? Um, and you know, should people make adjustments as they get older? [00:13:00]
Caroline: So when we age, sleep naturally will also change and it affects not only how much we sleep, but also a bit our depth of sleep and the pattern of sleep. And I think for a lot of people, this can be feel frustrating.
But one thing is to understand and also accept that this is part of biology, but also see that we can counteract certain aspects. So first of all, what. is changed when we aged. Um, maybe typically is that we have less deep sleep. So the sleep part also called slow wave sleep, where we have very specific brain activity patterns, so called slow as prevailing.
These are the stages when we sleep deepest and they have been related, um, to being involved in restorative brain and body processes. And It’s getting more superficial when you, the sleep gets more superficial when you age. And I think some people also realize that, [00:14:00] that they have the feeling they don’t sleep as deep anymore as when they were younger.
That also comes with more awakenings, a bit more fragmentation of sleep, sometimes also being longer times awake during sleep. And what you also see, um, that on average, the timing shifts a bit as well than your ideal bedtime is. So when you get older, you also start again to be more like early type so that you go to bed rather earlier, but also get up a bit earlier.
Now, There are practical adjustments we can do, and I want to emphasize that very clearly in this podcast, I always say a good sleep begins with a good day. So basically, whatever you do before that time is very, very important. And if you create a day that keeps you engaged, that keeps you active and balanced, and I will also say that keeps you young, it will be reflected in your sleep as well.
So specifically, one thing you can do is be physically [00:15:00] active, and it doesn’t just mean sports, right? It can also be active like walking, hiking, gardening, playing with your grandchildren, and just moving a lot, like walking a lot, being active. And not just the body, also your mind. So you’re never too old to learn new things.
I always say keep your brain in shape. It means that you are engaging in new content, that you may have new topics that interest you, that you read about, or maybe a new hobby, learning a new language. Just keep yourself engaged. And it’s very simple why this is so important, because our sleep is homeostatically regulated.
That means that The more we need our brain and body, the more we need deep sleep. And we see that if people are more engaged with sports, um, if they use their brain more, they will have deeper sleep. And what is also funny, it’s [00:16:00] even on a local level. That means if you need some brain activity, some brain regions more, um, often than others, these brain regions will sleep deeper at night.
And besides that, of course, this is just basically physical and mental activity, but also that you have and maintain social connections. I think staying connected to family and friends. So community reduces stress, gives you a sense of purpose, and that also contributes to better sleep. Practice relaxation techniques, not just before bedtime, but maybe just during the day, like try relaxation and breathing techniques, or these mindful moments where you just rest and be in the moment.
And this can also help you to settle your mind. before bedtime, but also if you, for instance, have one of these awakenings at night, instead of being like agitated, you might just try to calm yourself down again. [00:17:00] And the final point I want to say is also letting go of the stress that every night needs to be perfect.
It’s not just part of aging. I think it’s part of of like different life phases, that there are nights where you don’t sleep so well, where you have problems, maybe falling asleep or staying asleep. The worst thing you can do about this is to stress yourself about it, because stress itself makes sleep problems even worse.
I always say, if you have maybe some times where you wake up a bit earlier or wake up at night and you can’t go back to sleep, use this time productively. But not in terms of working, but more like do something you really enjoy, maybe listen to a nice podcast, read a light, enjoyable book, do some relaxation techniques or some visualization techniques and accept some natural variations that are just part of our life.
Mike: [00:18:00] Touched on a lot of different topics. I wanted to ask you about. So maybe I’ll just start with trying to fall asleep. So, I mean, I’m curious about what you mentioned when you wake up early and can’t get back to sleep. That’s, I am certainly guilty of that. But first I was curious about falling to sleep. If you are lying in bed and you’re rolling around and you just can’t seem to Get tired enough to switch off.
What are some simple techniques or a routine that people can get into to, uh, to get, be better at that?
Caroline: Well, when it comes to struggling and falling asleep, the first step is to understanding why you’re having. troubles, right? And identifying the root cause also makes it easier to find the right solution.
So really ask yourself, what keeps, what keeps me awake? And there may be simple reasons, right? It could be that you just had coffee before you, [00:19:00] before your bedtime, and maybe you’re sensitive to caffeine, and it could just make you more awake. And suddenly you don’t have this thrive of wanting to sleep anymore.
Here’s a side note. Not everyone is affected by caffeine. Some people really don’t have problems when they shortly before bedtime drink caffeine or drink coffee and drinks whatever, but some truly have. This could be one reason. It could be that it might be your diet. So maybe you’re like intolerant against something or you had a very heavy, heavy meal directly before sleep and your digestion keeps you awake.
Another reason can be that you just did some very arousing activity before sleep. Maybe you’re playing a very exciting video game. You were almost not able to, you know, stop playing, but then you just, you know, Five minutes before he wants to go to bed. Stopped it or you watch a very nerve wracking movie or show or you scroll through social media and it’s just really [00:20:00] agitated because of it.
And the third one, which I think many of us face is that. That you carry worries about your life, uncertainties, work, stress, personal challenges into your bedroom. And at the moment you try to really relax and close your eyes, it’s the moment when all these thoughts come up and you get into this cycle of overthinking.
Now there are, of course, practical, practical solutions to all of these sources, some of very simple, um, basically solutions, right? So one for, for the caffeine, the heavy meals, it’s very clear. I mean, if you start to realize also when you’re doing feed before sleep, you cannot sleep that well, just stop doing it and maybe stop at two or three in the afternoon, maybe change when you have your meals.
Eat earlier in the evening, not too close to bedtime. Also then have rather light food and nothing that really weights on your stomach. For [00:21:00] arousing activity, I would say set boundaries. First of all, identify whether there is something that might stress you or agitate you. And if you then do these activities, stop them one to two hours before the time and really give yourself the time to wind down and to settle and to relax before you Go to sleep.
And the third one lift the worrying and the rumination and overthinking cycles. That’s something that needs a bit more work. That means it’s not a one day solution that will help, but it’s something you have to start training by actively trying to letting go of the thoughts before sleep, basically not carrying these thoughts into your bedroom, to your bed.
The way you can do that is. By practicing already during the day to take more breaks, to have these, I would say, windows [00:22:00] of restoration where you pause for a minute and be in the moment, maybe do breathing exercises and relax. We are so used to be like constantly pushing through the day, being productive, but sometimes a few minutes during the day just to calm down and come a bit back to yourself in the moment.
Also that you learn to use it when it’s really needed before sleep, right? If you just practice it before sleep, it might not be practice as well that then you regularly do it during the day. And of course there are very specific pre bedtime techniques that you can start to do. One thing is to give your thoughts.
the time and space to think about them, but it should be before your bedtime. And one thing you can do is these so called very journals, where you write down all your worries. And after that, just tell yourself, well, you’ve dealt with that for today and you can look at it tomorrow again. [00:23:00] You don’t have to write it down.
You can also use visualization techniques, for instance, where you have these thoughts kind of like being carried away by balloons or something like that. And again, actively tell yourself, well, I’ve worried enough for today. And maybe after a good night of sleep, I also have the mind again for thinking about solutions to these problems.
And that what I always like to do is use the time before bed really to shift my focus also to something positive. Very simple, being grateful and counting your blessings and really listing also things you really like during the day. And it doesn’t need to be big, right? It can be things like, well, I had a great coffee in the cafeteria.
What a nice compliment from a work colleague. Um, You know, I read an interesting book and if you keep repeating that over time and making it a habit, what your brain starts to do, it’s also shifting more to the positive sides and it’s less likely to start [00:24:00] worrying and going to spiraling of worrying thoughts.
It’s really about a habit that you build and this time basically shift away from worrying and start to be more on the, on the positive feelings and positive thoughts.
Mike: What are some other reasons they can keep you up? What if I was like, Caroline, look, I’m actually not stressed at all, my life’s very simple and great, I never eat later than 7pm, and I, um, wait, what was the third one?
Um, And I don’t drink any caffeine. Yeah. What else? I mean, it
Caroline: could also be that it’s not, it could also be that it’s not your, um, ideal bedtime, right? Maybe you’re a late person. Maybe when you try to sleep at 10 and it doesn’t work, it could just be that your inner clock is telling you, well, it’s not night for you at the moment.
You can still be productive and awake. That could be a reason. I also emphasize if. Really sleep problems [00:25:00] and quality of life start to suffer because you don’t find any way how to to make yourself sleep better. Um, or sleep the way you want to sleep. Again, there are great resources out there and places you can go to really get consultation about sleep and finding a way to, also rule out that there is no like sleep disorder underlying that would need to be treated.
Mike: What are some very, besides being physically and mentally exhausted throughout the day, what are some effective ways to make yourself very tired by the time you go to sleep, to wind down?
Caroline: I really think it’s about, you mentioned it before, I think using your mind. using your body, but then also very actively relax, try to calm down, you know, have, I think half these, um, transition from being in [00:26:00] the active, you know, engaged mode to wind down mode and, and, and calm down.
And one thing that helps you in that is also light itself. So I think the worst you can do to get into a calm down state is to have very bright light shining down on you in the whole house. What I always use is like warm light, dim light, maybe LED candles. That really also get you in this, uh, like sense of being tired.
And of course, light is a very strong sidekeeper as you, as one would say, where it tells your body, well, now it starts to be. night outsides. And then basically the melatonin, the hormone, the darkness hormone starts to be produced. And at one point tells the body that it’s time to sleep. And other thing is also temperature regulation.
That is very important. Um, and when it comes to temperature there, um, one of the [00:27:00] most important signs for the body to go to sleep is that your Core temperature is cooling down a bit and your extremities so hands and feet get warmer and because they get warmer they also actually release some of the heat so the core body temperature can Basically go down and it’s one of the most important changes that actually initiates sleep
Mike: So your as your your core body temperature cools down by sending the heat from the core to your extremities Is that right?
Caroline: Exactly. Exactly. And some people have problems with that because they have cold hands and feet, some cold vessel constrictions. So when your blood vessels are like, like closed in a way or smaller, and then you have less of heat release. And there is also a very simple solution to that. So you can take a warm shower before you sleep.
Or a hand or foot bath, something that you [00:28:00] can do as well that can help you if you have problems with that.
Mike: I have read that before, that a hot bath before bed can be very beneficial because getting out of the hot bath, as your body cools down, it’s indicating that that cooling of the body is an indication that the, that the body is time for sleep.
Is that right?
Caroline: Exactly. That’s one thing that then after to cool down, but also because your hands and feet are warm, so they release the heat from your core. Um, but again, that’s something that could be very individual. I also know some people that probably would not sleep that well after hot bath. They would think, well, it’s even worse afterwards.
It’s also something you have to try out yourself. And it’s also, again, not a solution that might fit everyone, but I think it’s beneficial for a lot of people. So maybe something worth trying.
Mike: Would you recommend, uh, sort of late night or evening exercise, or is that how would you see exercise in their lead up to sleep?
Caroline: Um, there are many studies about [00:29:00] this. And I recently read a review that basically said exercise in general is something good for you, independent of the time of day. But there are also some controversies around that, especially if it’s. close to bedtime exercise that really agitates you again. If you’re suddenly, you know, in a very maybe aggressive mode, maybe it was like contact sports you did, or you’re basically having a lot of like hormonal changes that make you very awake, might not be ideal for you.
But again, that’s something you have to try out. Me, for example, when I do intensive sport shortly before bedtime, I’m really tired afterwards. I can directly go to bed. No problem for me. I know people that really need an hour or two afterwards to calm down and then be ready to sleep. So there, I think it’s again, trying it out for yourself.
I recommend anyway, doing exercise, but maybe you have to move it Um, from close to bedtime, if you realize [00:30:00] that’s not good for you to earlier times.
Mike: Is there any point when you would recommend people take dietary supplements for sleep because they feel this isn’t working?
Caroline: I’m not a big fan of supplements itself, um, because there’s not so much research out there really supporting any of those.
Um, I think a lot of times magnesium was in the media, I think magnesium is good in terms of like basically for your muscles not to have cramps and so on. There is not really much evidence showing that it improves directly your sleep. If at all, very, very lightly. Of course, having a bit of magnesium may be just in general beneficial for you, also when it comes to muscles.
I’d also, there is no study showing that it hurts your sleep, so there’s also no harm to it if you try to use it. But Um, all the supplements I don’t, I would [00:31:00] not know of. Um, and when it comes, for instance, to melatonin, this is something that is, that needs prescription in Switzerland. So you can not just buy it over the counter.
And I think this is also good because a lot of people forget that melatonin is not a sleep hormone. It’s not there to just make you sleep better. It’s. Uh, circadian hormone, it’s the darkness hormone and the importance when you use it is more that when you have like jet lag or your inner clock shifted that it can help you re shift it and it would need to be taken very regularly at right times and I think sometimes it’s just misused and just taken whenever you try to sleep and cannot fall asleep.
So I also don’t recommend that without not having it prescribed by an expert who knows exactly how to use it correctly.
Mike: Is so things like sleeping pills or even um antihistamines which typically make you drowsy when you take one of [00:32:00] those It feels like you’re having a good sleep because it just knocks you out and you sleep.
But also my understanding is that’s actually not the case. Is it true that typically a lot of these, um, sleeping pills would actually give you a, that your quality of sleep wouldn’t be as good?
Caroline: Exactly. So I would also recommend taking any sleeping pills without having it prescribed by a sleep expert.
And it should also never be taken long term. There are multiple reasons for that. I mean, it’s not necessarily natural sleep that you have in a way that typically would be the case. You might have a change in your sleep architecture that’s is not ideal for you. It is also that it can, you can get addicted to these.
And I think there are much better ways out there to improve sleep. I give you an example. So one of the most common reasons by people or sleep disorders that people have is insomnia problem to [00:33:00] fall and stay asleep. And in most of the cases, this can be very well. And also for the longterm treated with cognitive behavioral therapy.
Okay. Basically changing habits and your behavioral patterns. And there are great programs out there that are prescribed by experts. If you have problems with that, and the first line of treatment should never be medication.
Mike: Going back to waking up. I am certainly someone who wakes up with a buzzing mind more often than I would like. And besides using that time to do something I enjoy if it is particularly early, is there anything you would recommend to get back to sleep?
Caroline: I think you should not try to actively fall asleep again, like pressure yourself.
Um, I think you should use time to maybe get up. Like, of course, you can first try to [00:34:00] stay in bed for some while and try, but if you realize, hey, it’s not working, don’t stress yourself, get up. Um, don’t turn on lights or anything that arouses you, but maybe, you know, sit in a, in a chair, maybe read something with a very, um, dark light.
Try to, to get back to something that relaxes you again, and then try again to sleep if sleep doesn’t come. Don’t, um, very too much. I always tell myself, um, sleep regulates itself to a certain degree. So when I have a bad night, my sleep pressure will be higher for the next sleep period. And that means I will also sleep deeper and more consolidated the next night.
Mike: Is the concept of a sleep bank true? I remember learning about this in school and the theory behind it is you, If you, you know, if you require 8 hours and then one day you only get 7 hours, well then at some point you need to get [00:35:00] 9 hours to sort of give that back to the bank because you’ve essentially borrowed an hour.
Is that, that conceptually, is that true?
Caroline: It is partially true. So there is homeostatic effects to that. That means if you like skip a few hours a night before the next night, your so called sleep pressure is higher. And then it will be shown at one point that you have deeper sleep. So it’s not just the length of sleep, also how deep sleep it will be more pronounced.
And. You might also sleep a bit longer. It might not necessarily be exactly an hour because you also sleep deeper, but it might be a bit longer, but I think what I would emphasize is that this is like maybe on a daily basis, sometimes. Okay. But you shouldn’t bank sleep by having. Day after day after day after day sleep deprivation And then wait for like two weeks later to say catching up on sleep.
I think that’s not ideal to do It’s okay if it’s a few nights here and then but it [00:36:00] shouldn’t be the regular habits that you do.
Mike: Yeah, I think Thanks to my partying days in my 20s, I think realistically my deficit is big.
Caroline: Hopefully you have now recovered from that. Um, I think some people face that too, but I, I also think there, it’s just important that people understand.
It’s okay to have once a night not so good and maybe going out another night, but it shouldn’t be. very regular and back to back, right? Something that is not ideal for brain and body health.
Mike: How effective are naps for recovering that sleep? If you only got six hours and you need eight, how effective would a 15 minute nap be throughout the following day?
Caroline: So I want to emphasize two points.
Um, On one side, some positive aspects about taking naps. [00:37:00] If you really cannot get enough sleep at night for whatever reason, maybe you have a newborn or your work just didn’t allow for you to sleep the amount of hours you need. A power nap can certainly help to also give you again a bit of an energy kick during the day.
But there I recommend not to sleep longer than 20 minutes. For the reason that also after 20 minutes, even if you don’t have the feeling you really were asleep, overdosing helps you to give you some productivity, some feeling of, of awake and energy, right? If you sleep long, and especially later in the afternoon, what happens is that for the next night, your sleep pressure will be reduced.
And that means that it can be that the night again is not that’s consolidated and you have fragmented sleep. And here I also come to the negative side. If you can, I recommend to really sleep specifically at night, For [00:38:00] enough time and not nap, because if you start the habit of napping long, what happens is at night, you will have more problems sleeping consolidated because you have sleep.
And there is increasing research that it’s not just how much sleep you had over 24 hours. That you say, well, I can just split it up right in four times, six hours or whatever. And I’m sorry about four times two hours or something like that, but that a longer consolidated period might be important and not just the sum over 24 hours that you got in sleep.
Mike: I wanted to ask you about the, with the popularity of smartwatches, the, um, the rise of sleep tracking devices, how useful is it to monitor your sleep via, via a watch?
Caroline: Um, I think it’s again, um, [00:39:00] who side a perspective on sleep tracking? Um, I think it can be, Interesting to track your sleep and identify patterns and maybe learn more about sleep, but it also can create unnecessary pressure and even misinformation about sleep.
First of all, when you think about the positive side, um, I always say you can use the sleep tracker as like a tool to better understand your sleep a bit in objective way. That means for instance, you can start to learn patterns. I, for instance, use my sleep tracker, not to specifically look at how my sleep score was or how sleep stages look like, but rather, for instance, how did my heart rate look like when I slept?
Because that’s normally very accurately measured with these devices. And what I realized is, and that’s also shown in literature, when you, for instance, have drink alcohol before sleep, your heart rate is higher during sleep. So your heart might have less of [00:40:00] relaxation during sleep. Or before I get sick, actually a few days before I get sick, I also realize that my heart rate starts to be higher than normally during night.
But what I want to emphasize is there are certain risks and limitations to the trackers, um, because the precision of these trackers varies greatly. And. They typically rely on movement and sometimes heart rate rather than brain activity. And brain activity is typically the gold standard to really precisely define the amount of sleep, but also your sleep stages.
So you can have very inaccurate information about how your sleep staging was, right? You might get an information like I have 5 percent deep sleep and 20 percent REM sleep, but very likely these numbers are not correct. And what that means is that. This can lead to more problems because suddenly people start to worry about something that might not even be a problem.
And there is even a disorder that started [00:41:00] because of this possibility to do sleep tracking, because some people become very fixated of reaching the perfect sleep. Maybe they. check to have a sleep score of a hundred from a hundred. And this ironically can even lead to sleep problems because they have more stress and a lot of sleep, um, experts they suddenly have in their praxis, people who basically start to have sleep problems because of trying to get the perfect sleep, which is very, uh, very, which is actually not ideal.
When you think about this, it’s very ironic. Yes. And. What I then say is like, use, you can use it, but be very, like, have a healthy skepticism about it. And understand these are tools, but they’re not definitive measures and diagnostics measures of your sleep. And also avoid letting the device dictate your own perception about sleep.
If you feel great during the day, if you feel rested, You are rested. Trust [00:42:00] that. Don’t then look at your sleep score and say, Oh, it was only 50 today. Maybe I slept bad. So maybe I should feel bad now. Right? I think this is not the right approach. So don’t use it to add more pressure. More like an exploration tool, I would say.
Be curious about what you maybe see about your sleep or some patterns that emerge.
Mike: Yeah, I’m curious about, um, how data and technology evolves, um, to give us more insights about sleep. Do you have many insights in some emerging areas of research in sleep science that gets you excited?
Caroline: Well, there are so many questions about sleep that are not, that are not answered yet.
And I think with every study I do, there are more questions coming up than answers. I think one very important thing is that we still don’t really know exactly what the functions of sleep are. And more specifically, also, which aspects of sleep are important for which functions of sleep. And so [00:43:00] one area I’m very interested in is to develop new ways of modulating brain activity during sleep, very specifically, and see what happens during sleep.
to brain and body functions when I do that. For instance, um, I’m very interested to see how deep sleep and specifically these low waves that are these brain activity patterns that are characterizing deep sleep, how they are important for our cardiovascular health. And, you know, when you have a better understanding of that, you can also develop interventions and tools that can target these brain activity patterns.
And on one hand, maybe improve health, but also restore health in case you have, for instance, sleep problems or certain disorders that might also have sleep as a fundamental component of the disorder itself.
Mike: I wanted to clarify something. You said we don’t know the functions of sleep. What do you mean by that exactly?[00:44:00]
Caroline: There are always like more and more functions and ideas coming up. So what is really important that sleep is there and what can also happen without sleep, right? That’s an important question. And now we get more and more functions that might really only happen during sleep. I just give you an example.
Only a few years ago, it was recognized that sleep might act as a dishwasher to our brain. So there is. Due to our activity of our brain cells, of our neurons, there is also toxic byproducts produced. And at one point they need to be cleaned away. And now studies found that this specifically happens during deep sleep and is not as effectively or actually almost not at all happening during wakefulness.
So it’s really something that requires sleep in order to have a healthy brain. But this was only discovered a few years ago. And I, um, had a study recently which really showed [00:45:00] that sleep is important for, like, basically having improved cardiac function the next day, right? It was also not that clear how important sleep really is for functions beyond the brain.
And that’s also starting to emerge more and more with coming studies.
Mike: Interesting. I also thought that we seem to be the only species that limits the amount of sleep that we have. Everyone, every other animal seems to sleep all the time.
Caroline: Not, I mean, there’s, I mean, it’s also a huge variability, uh, within humans, but also when you think across like the animal kingdom, it’s a huge variation how much hours are slept.
And also even the simplest animals, I mean, even without the brain, for instance, the jellyfish that only has sleep. single neurons is sleeping. So it’s a very universal need, but maybe the functions are not the same for all. Right. Because if you don’t have a brain [00:46:00] and the heart, right, it might not be important for your brain and your heart might have all the restorative functions.
And so I think it’s also important to somehow understand like how it’s important for us, but also for all the species, right.
Mike: Now, one of the things I wanted to ask you about also is the, herencia initiative, which you are involved with.
Can you tell me what that, what that is you’re working on?
Caroline: Yes. Maybe I start first with the link to sleep. So the herencia initiative is about Alzheimer’s disease and finding or creating, um, a platform that’s. is holistically combating Alzheimer’s disease. Now, why I was starting to be interested in Alzheimer’s disease is that More and more evidence, um, comes that there is a very tight link between sleep and Alzheimer’s and in a bidirectional way.
So it’s assumed that [00:47:00] sleep is not only negatively affected as a consequence of the disease itself, but might be even causally involved in basically developing the disease itself. Now, Alzheimer’s itself, the problem there is that, um, it’s affecting many of us, right? So over the, I don’t know, like around 55 million have dementia.
Most of these cases are because of Alzheimer’s. And the biggest problem we face is that the biggest risk to develop Alzheimer’s is aging. And because we all get older now, societies are aging, we will have more and more people being affected by it. And the, the, the, the incline is very steep affecting everyone globally, but there is also a problem that specifically low income countries are much more affected by it.
Now, it’s also the only leading cause of death where we have any solution [00:48:00] to halt the disease, to prevent the disease, or to even substantially slow it down. And of course, when you think about that in the future, if we continue like that, it will crash our healthcare system if we don’t find one. And the Harenci Initiative wants to basically change that.
And to, to emphasize Why we need an intervention initiative, it’s also the question why we don’t have a solution yet, right? So, of course, there’s a lot of research going on , but to date, we don’t have a solution to fight Alzheimer’s. And, um, one of the problems is that we cannot diagnose early enough.
So at the moment, when we diagnose Alzheimer’s disease is a time when We basically already have a lot of things destroyed in our brain. It’s time when we have suddenly cognitive deficits. But this only happens about [00:49:00] 20 years into the disease when already a lot of irreversible brain damage has happened.
And that also means the time we have now clinical trials and test drugs and other interventions, it’s likely coming too late. And another problem that we face is that Alzheimer’s disease is having multiple impact pillars that we need to address to really solve it holistically. On one hand, we have the research side, so we need to mechanistically understand, um, what, what is the reason for the disease?
What are pathways that we need to target? But then it’s also the health side. So how do we translate that into interventions in early And the last one is the social aspect. So it has a huge social burden, this disease, because it’s not just affecting actually people who have the disease themselves, but the family around, because most of the times the family is doing the caregiving [00:50:00] over multiple years.
And it’s a huge burden. And also what I mentioned before, it’s, um, a disparity, how much people are affected. So lower income countries will be more affected and they also are the ones that have the least resources. So also there it is that it needs to be taken into account and Terence initiative is doing that by first of all, trying to be more efficient and accelerating the way we find solutions for Alzheimer’s disease and by combining all these impact pillars in one centralized hub.
But of course, the question is, how can we do that? Why can we accelerate it? And the key aspect there is that we have access to a very, very special population that is in Colombia. around the Medellin area. And there, it’s the world’s largest cohort, around multiple thousands of people that have a genetic form of Alzheimer’s [00:51:00] that is deterministic.
That means they have a mutation in a gene, and that leads to Alzheimer’s with 100 percent certainty when they are 45 to 50 years of age. And this is very unfortunate for them, but it’s a unique window of opportunity to basically find an early biomarker and the treatment for Alzheimer’s disease. I can quickly explain you why, because if you now know that someone develops Alzheimer’s disease, this solves a huge problem we have in the general population, because there we don’t know whether someone develops Alzheimer’s.
And that also means you cannot really, in a reasonable timeframe, innovate on biomarkers, right? Because you would basically have to measure thousands of people today, wait decades, and then, When they developed Alzheimer’s, some of them, you go back and see whether they differed in any kind of biomarkers.
And we don’t have the time for that. But in this population, you can measure them [00:52:00] already now, you can measure them from the moment they are born, and you can look whether there are certain aspects changed, for instance, molecular aspects in the blood, or functional aspects in how they perform tasks or other things.
And you can see whether there are risk markers that tell you decades before the classical cognitive onsets, whether there is a risk for Alzheimer’s or not. And it also will help to test treatments that are already available now, much earlier, right? We can see whether some of the drugs that have been in studies and that were not that successful or only had a small success rate in slowing down the disease a bit, whether They are more effective if they are applied actually earlier in the disease.
And the final reason why they are so important is that of course, if you know that a person should get Alzheimer’s at a certain time, but they [00:53:00] don’t get it. In the end, you know, they have a protective factor, and that means they might have also a solution for the disease itself. And that’s something that was already found in this population, a very beautiful example.
Um, she’s called Aliria. She died a few years ago, but she didn’t die because of Alzheimer’s, even though she had this genetic mutation, she died when she was around 70 years of age, so much later than the others that are affected, and thanks to her brain donation, they found that she has not just the disease, but she also had the cure in herself because she has a protective gene that protects her from Alzheimer’s.
It was the initial start to understand there might be genes that protect us from the disease, so now we can try to find gene therapies to basically counteract Alzheimer’s. And that means I’m absolutely convinced that the place where [00:54:00] a solution comes out for Alzheimer’s will be around this population.
But now one problem is there is population, but we still don’t really have a platform to innovate holistically. And that’s the second part of the initiative. So we want to build now around this population, um, troll or like a world leading center where research, health care and social aspects are combined in one local place and basically enable also other companies to innovate on this population.
And at the same time, directly translate research findings into diagnosis that. And and treatments that are available to others and socially, of course, to make sure that we don’t exploit this population that we also give back to them that they own, um, what they contribute, right? So that they have the chance to.
Directly also benefit from any intervention that comes [00:55:00] out that they are socially supported and so on. And it’s very important now we are at the stage of basically getting investments for this idea. So if anyone is listening to that and it’s really interested in being part of this fight against Alzheimer’s and innovate on that aspect and invest in the Alzheimer’s theme, probably a good time to reach out to us.
Mike: Now that’s a story. How big is the initiative at the moment in terms of number of people, amount of funding and how long has it been existing for?
Caroline: So this, the research around this population is, is already, um, 30 years in the making because one professor, Professor Francisco Lopera, who started this initiative, he found His population almost 40 years ago, he had like a person coming into his [00:56:00] praxis and reporting like signs of dementia, but this person was like around 40 years of age.
And then he was already suspicious. And that’s very strange because it’s all signs of Alzheimer’s, but this person is really young. Right. And then interesting thing was that. While talking to the family members of this person, family members said, well, he’s not the only case. We have many more in our village that are like that.
And so this population was discovered. And then he with huge dedication for the research, but also for the patients themselves to advocate for them to find solutions for them. He started to research and there are like breakthrough of the breakthrough coming out from this population. There are many, many, um, highly ranked, highly cited publications from this population and from this research group coming out.
Um, they won’t yet identified two protective genes that protects from Alzheimer’s, [00:57:00] but it’s still at the stage where everything is. rather low level where we, there is not so much funding or basically there is interest from many companies, but there is not the space to do all this research, to do all these trials that are needed and to have like a, a control device or a legal structure around it to, to also manage that.
And that’s something you want to change because basically it’s like, everything is already there We just need to have a better platform to Take advantage of this, but the whole expertise and the population is there. Now we just need to provide basically the infrastructure and the platform and the sources to bring it to the next level.
Mike: Has since the discovery of this population in Colombia, have these people with this gene been found anywhere else in the world? Or is it really isolated to that one place?
Caroline: I mean, it’s a genetic mutation, a very specific gene. You can also find it in other [00:58:00] places in the world. Um, also some people in Switzerland likely have that very few, but it’s very rare.
And the problem is to identify them in the general population takes forever and you don’t really get the numbers you need. There is no place in the world, at least not yet discovered that has such an amount like clustered together.
Mike: Caroline, this has been an absolute pleasure talking to you. If people want to know more about you and your work, where can they go and find you?
Caroline: There are many homepages you can find. Of course, LinkedIn is a great, great platform.
I regularly check that and you can also find me on the ETH homepage. If you Google my name, there is my work email mentioned and we have our own, um, website, uh, in relation to our book that came out, it’s, um, I can also give you the link, but it’s called sleepfulness. ch. And then it’s also like contact [01:00:00] details about us and our backgrounds and CVs that you can find.
Mike: I’ll put all of that details in the show notes of the podcast.
Caroline: Yeah. So I will look forward to feedback or people reaching out also if they’re interested to learn more about this Herentia initiative.
Mike: I think it’s really amazing work. Uh, I’m really, really glad you shared that with me.
Caroline: Hey, yeah, I just hope we can make it happen because I really.
From the bottom of our belief that this is where we have the solution for a disease that has no solution yet. I just hope we find the means soon enough to really get that started. So keep your fingers crossed for us that this is working out. That is great.
Mike: Caroline, thank you very much for your time.
Caroline: Thank you very much, Mike, for inviting me.
Mike: Bye bye. Caroline: Bye.
