This episode of the podcast features Dan Pardi, a sleep researcher at Stanford and Leiden University in the Netherlands. Dan is the CEO of humanOS.me, an application designed to promote health mastery. His specialties include building systems for health, behavior optimization, and habit building. He discusses the foundations of sleep, sleep physiology, why sleep matters, and tools and tips to optimize your sleep.
When you are done listening to part 1, here is part 2 of this podcast
8:58 The four stages of sleep
16:42 The two-process model of sleep regulation
21:36 Physiological benefits of slow wave sleep
25:22 Sleep regulates immune system
28:17 Sleep deficit, inflammation, chronic disease
37:45 Why bodybuilders need to get enough sleep
39:32 Inadequate sleep and obesity
41:53 sleep loss and attentional networks, ADD, ADHD
48:20 Working memory and executive function
50:03 Obesity promotion and addiction promotion
53:29 Wake network
57:39 Ghrelin and leptin levels during sleep deprivation
1:03:33 Circadian rhythms
1:09:05 Technique to hack sleep time and wake time
1:11:16 The 24 hour circadian rhythm
1:12:54 The “photic nutrition” we get from sunlight
1:14:22 Psychologically different states induced by darkness
1:16:23 Hunter gatherer sleep patterns
1:22:50 Things you can do to get a good night’s sleep: Dark, cool sleep environment.
1:22:25 ChiliPad refrigerated sleep topper
1:28:30 Taking a hot shower or sauna before bed
1:30:28 Eye mask and ear plugs
1:32:02 Good sheets and mattress
1:33:18 Restorative Sleeper concept
1:39:51 OURA ring
1:42:02 Restorative sleeper model
1:43:08 HEPA filters, negative ion generation, and blackout curtains
1:43:55 Eye mask.
1:44:40 SAMINA sleeping system
1:46:37 Meal timing and sleep quality
1:48:04 Electronic devices before bed
1:49:18 F.lux app, blue blocking glasses, and a wind-down routine
1:50:37 Journaling before bed
1:51:30 Listening to a podcast before bed
1:52:13 Reading philosophy or spirituality before bed
1:53:08 Eating before bed and maintaining blood sugar
1:53:57 Blood glucose, dim light, insulin, cortisol
1:56:15 Getting circadian system under control
1:59:50 Dan’s HumanOS program
Connect with Dan Pardi:
Selected Links from the Episode:
- William C. Dement, MD, PhP
- Jari Antero Laukkanen, MD, PhD
- Marie-Pierre St-Onge, PhD
- Alexander Borbély
- Karen Spiegel
- David F. Dinges, PhD
- Kenneth P. Wright, PhD
Related & Recommended Posts:
- Sauna Usage for Brain and Heart Health (Guest Jari Laukkana, MD, PhD) - HumanOS Radio
- Does What You Eat Today Affect How You Sleep Tonight? Yes - Dan Pardi
- The Two-Process Model of Sleep Regulation
- Chrononutrition: A Timely Intro to This Key Component of Your Health (Part 1) - Dan Pardi
- Chrononutrition: Shortened Eating Windows, Breakfast-skipping, Eating Late, and More (Part 2) - Dan Pardi
Sleep Tech Discussed in the Show:
- ChiliPad - cooling & heating mattress pad
- ActiGraph - wearable activity and sleep monitoring
- Zeo Sleep Manager - EEG brainwave monitor headband
- OURA Ring - sleep tracker & wellness ring
- Beddit Sleep Monitor - sleep tracker
- Fitbit - activity tracker
- Polar Sleep Plus - sleep tracking & analysis
- SAMINA Sleeping System - sleeping system
- f.lux - removes blue spectrum from electronic devices
- Blue Light Blocking glasses
Daniel Schmachtenberger: Welcome to the Neurohacker Collective podcast. My name is Daniel Schmachtenberger. I’m with Neurohacker Collective work here in research and development. We're very excited to have Dan Pardi with us today talking on the topic of sleep. This is the first of a two-part series we’re going to do where we get into the foundations of sleep, sleep physiology, its effects on psyche, cognitive performance, health and foundational things. To optimize sleep, next time we'll be getting into a more advanced sleep pathology, sleep physiology and sleep hacking.
Dan is a sleep researcher at Stanford and at Leiden University in the Netherlands. He actually did a lot of the groundbreaking work on the effects of GHB on sleep which is really fun and many interesting things relating to health, wellness, biohacking and the topic of sleep. I think that if you really take the things that we talk about here today and implement them, it’s probably worth as much or more than everything else that you could do in your healthcare combined. This is just that foundational of a topic. That’s why we’re doing this is a two-part series because that still just scratches the surface. Dan, it’s a delight to have you here. Thanks for joining us.
Dan Pardi: It’s a delight to be here. I do quite a few podcasts on the subject and I’ve been really looking forward to this so thanks for having me on.
Daniel Schmachtenberger: Yeah this is fine and even though today we’re going to be doing foundational stuff that some people are already aware of, I imagine there’s going to be more granularity and insight that happens so important topic. Let’s just start just kind of at the very top with what is sleep? What’s actually happening when people sleep? What’s the evolutionary purpose? What’s the physiologic purpose? What do we know about it? What’s the mysterious?
Dan Pardi: Yeah that’s funny sometimes those questions that are so simple are also some of the hardest to answer. What is sleep? What is health? I rem giving a presentation one time and somebody asked what is health? I stumbled on that one. I hadn’t thought about a clean answer so sleep is something that happens across really all species and live on this planet. It is likely in response to the fact that our planet undergoes cycles of light and dark and for most but not all animals because you have diurnal and you have nocturnal animals. Some are up during the day, sleep at night. Some are up at night, sleep during the day.
You have a period though where the body goes into rest. Now it used to be thought that sleep itself was a exclusively behaviorally quiescent time. The brain and body would shut down there wasn’t much going on, it was just a rest period. We know that’s not the case now. In fact, there are some parts of the brain that are more active during sleep than at any other part of the day. So also it's also very, it’s been a challenge to address and to even kind of declare what is the purpose of sleep. We know that there’s multiple things that happen but expressing one unitary uniform pieces about what sleep is has been sort of notably challenging.
We do know however that for example some very important things that do take place more recently, we know that during sleep, the brain will sort of power cleanse itself and clear out the byproducts of energy usage that took place during wake time activity. As the brain is awake it’s thinking, it’s using a lot of energy. In fact 25% of glucose goes toward this small organ. It takes sort of lion’s share or disproportionate amount of energy to run the brain. That’s probably not too much of a surprise. It’s doing a lot.
As a result of that high energy usage, we see by energy products and those byproducts needed to be cleaned out of the brain. If not, they could become toxic and build up. We see that and actually we now see a very clear relationship between sleep loss whether it’s from chronic sleep issues like sleep apnea or obstructive, yes, sleep apnea or insomnia and both sort of beginning of the disease, the advancement of a disease and even premature mortality. There’s really no part of the body that goes untouched when we don’t get the sleep that we need. It is a physiological requirement. There is no way around it, but in our world today, we definitely have things that encroach upon our sleep. A lot of it is voluntary sleep curtailment because of the way we live because of extended work times, because of extended commute times, because of captivating and engineered for reward activities and shows in the evening, we stay up later than our body wants to.
That is a challenge that we have to face. I think one of the really great things about listening to this show now is empowering sleep with value and really attending to it is one of the most important things you can do. That’s really what learning about its intricacies will yield, motivation to attend to it in a manner that’s going to get you results that you want, health, performance.
Daniel Schmachtenberger: So it is this interesting thing that we’re learning more about sleep and neuroscience and endocrinology and cellular science and psychiatry like all these fields are studying sleep and learning more and more about it every day, every week, and yet there’s still some kind of like profoundly mysterious things happening like what REM sleep is doing and what aspects of memory consolidation are in REM versus Delta and we’re going to get into what the different phases of sleep are and what happens in those different phases. We kind of know more as we get more granular. Is it pretty fair to say in the way that matches most people’s intuition, the purpose of sleep is physiologic regeneration. There’s lots of physiologic and psychological regeneration.
Dan Pardi: I think that that’s fair to say.
Daniel Schmachtenberger: And the things like immune activity and anabolic process and certain kinds of antioxidant process, like these whole things that pretty much only happen during sleep or during phases of sleep or if we’re not getting enough of those phases, those critical physiologic processes are just not really happening.
Dan Pardi: Yeah that’s absolutely true. We know pretty much all as I was saying earlier there’s no part of the body that goes untouched if you’re not getting good sleep and yes that is what actually happened so you know if we have selective suppression of REM sleep or you’re not having to get deep sleep or you don’t get enough sleep so your sleep staging is fine but your sleep time, the amount of time that you're sleep is inadequate so your body wants to sleep more but you’re not giving it that, or your sleep timing is off, which is a topic that we can get into.
Let’s say you just because eight hours is used commonly as get eight hours of sleep. You typically sleep between midnight and 8:00 but you decide to go to bed between 4:00 and go to bed at noon. You’ve got eight hours of sleep but that’s not going to actually be restorative. It’s not going to do everything you want sleep to do because you've slept during a time when your body is not used to sleeping in that period. Now that doesn’t mean if you didn’t go to bed at 4 AM every night and wake up at noon, if you do that every day, your body would adjust to it and you would do well there’s still some challenges because you’re having to then sort of control your environment a little bit because we have this very intimate relationship with nature, the lights coming in to the day, it's the tone of that light, the intensity and in a natural environment without artificial light, without if you’re living in Savannah for example, those cues are going to help to signal the timing of physiological processes of which sleep and wake behavior are 1/2 depending on how you look at it.
Absolutely, your body is this is as a fundamental state, we try to cheat it a lot. I’m not saying that as some sort of condemnation but hey you shouldn’t do it, just happens. It happens in our world. There’s so many good and not so good reasons why it does happen. But again I think having an awareness and then understanding some of the things that are actually going to affect it is going to change the rest of your life. It can actually change the rest of your life and how long you live.
Daniel Schmachtenberger: So you touched on a lot of things I want to come back to in terms of circadian rhythms and chronobiology and chronotypes but like to just have some foundation so that people to understand more. Can we dive into what’s happening during sleep in terms of phases of sleep so REM and non-REM, and Delta sleep.
Dan Pardi: Great place to start. Is sleep this monolithic state? No. We know we go through different cycles and different stages during sleep. The two big categories are non-REM and REM. REM was described first Bill Dement at Stanford, wasn’t the first to describe it but was he found that the first sleep clinic in the world and did huge amounts to you could say popularize sleep as a meaningful medical and scientific subject so he’s made invaluable contributions to the field. He also has probably one of the most popular classes at Stanford and he tells people, he turns off half the lights in his class and says if you want to get some sleep, you can do it over here and he says he takes it as an honor if people sleep during his class because they are listening to what he says.
But anyhow going back to deep sleep stages, REM was originally identified by rapid eye movement so when the brain is in this stage, you can see ocular activity behind the eyelids. The eyes move so I’m not sure if you can see but I’m moving my eyes back and forth behind my closed eyelids and that behavior, that physiology was visible to people that were observing people who were sleeping. It is a very distinct state from non-REM. So non-REM is what we first enter into.
You go there’s four different stages, stage one, two, three and four. Stage three and four are now discussed as one stage called slow wave sleep that’s a little bit of sort of the history there but now it’s stage one, two and then slow wave sleep. Stage one is very light. You might in fact think that you’re still awake but a polysomnography so this something that is measuring brain activity and also other parameters around the body that is detecting yes indeed you are in stage I sleep. Stage two is a little bit deeper. There’s other physiological characteristics of that, sleep spindles, K-complexes and then the deep, deep sleep the one that actually really will reduce a lot of what was considered sleep pressure which is this factor that actually makes you feel sleepy, that’s taking place during slow wave sleep. We want that.
We feel really good typically when we get slow wave sleep over the night and we go through different cycles. In the beginning, this is a common way that sleep happens. You have 90 minute cycles and about 4 to 5 over the night. During the first cycle you have a lot more non-REM sleep and you have a little bit of REM towards the end of that cycle but as the night continues in the last cycle you have a lot more REM and you have a lot less slow wave sleep or non-REM sleep.
Now REM sleep is also considered the gateway to waking. Your physiology if you look at your brainwave activity during REM, it looks almost indistinguishable. I mean it is distinguishable from a PSG but if you were to look at the squiggles made on the paper, it looks just like wake activity compared to non-REM, you see that it’s this cycle activity that gets deeper as the sleep gets deeper sort of the amplitude of the rhythm elongates and heightens and so very, very distinct in terms of what these sleep stages look like when you’re measuring brain activity.
You also during REM, you see heightened blood pressure, heart rate. This is a stage where you are actively dreaming. You also have muscle paralysis which is a physiological conserve mechanism so makes a lot of sense if you’re let’s say you’re dreaming that you’re fighting somebody, you actually want your body to have its muscles paralyzed because if you don’t, you could actually injure somebody and there’s a disorder called REM sleep behavior disorder where that paralysis doesn’t happen and actually people have been acquitted of murder because they have been able to verify that yes they have REM sleep behavior disorder and they were dreaming they are being attacked and they choke their bed partner.
Sad but true and illustrative of what’s happening here. Those are the different types of stages of sleep that is you could look at something called a hypnogram which monitors the sleep activity across the night. Yeah, there’s a lot of different things that are taking place during sleep, the concatenation of the different stages so how sleep stages will link from one to the next is also important for sleep doing what you wanted to do and sleep can be disrupted in a variety of ways. I was mentioning earlier it can be truncated so you want to get eight hours but you get six, it could be shifted, you slept eight hours but it was at a time where you usually don’t sleep.
It can be fragmented where you have lots of what are called micro-arousals where you’re waking up. You’re waking up frequently although people that have sleep apnea have a lot of micro-arousals and fragmentation but you might not know it. You went to bed at midnight, you woke up at 8:00 and as far as you’re concerned, you’re asleep the whole time but on an EEG, you kept transitioning out of sleep in to wake a little for just a second. You don’t remember any of it but you feel like to got no sleep at all and then you can also have certain stages suppressed so for example, antidepressants will suppress REM. Alcohol will suppress deep sleep so there’s a lot of different ways that sleep can be disrupted or inadequate but those are different sleep stages and how each one of them can be perturbed.
Daniel Schmachtenberger: So just so people can think of it kind of simply, let’s say we’ve got lighter sleep, phases one and two of non-REM sleep. We have REM dreaming sleep and we have deep sleep. Deep sleep meaning Delta slow wave to just roughly think of it that way is fair-ish and so we want make sure there’s enough total sleep and specifically there’s enough REM in Delta which are the most [inaudible 00:14:36] developments. Right?
Dan Pardi: Yeah I think, perhaps I would switch that a little bit. I’d say light, deep and then REM since those are sort of both categorized but yes you do want to get an adequate amount of if you miss a lot of let’s say light sleep, you're going to have less physiological consequences and yet still important things are happening during that phase so the idea of necessarily in the past some people have written about all you need is REM sleep and the idea that there are only certain types of sleep are actually physiologically important is not true. It’s also again how they concatenate with one another or link one to the next and then adequacy of time in those different stages.
Daniel Schmachtenberger: I don’t know that I have ever seen insufficient amounts phase one and phase two relative to REM and Delta which is why it's just not really an issue to think of. It’s like getting enough sleep and then specifically getting enough REM and Delta which are the ones that can be insufficient relative to total sleep amount. Would you say that’s fair?
Dan Pardi: Yeah I would except here’s the one issue if you are significantly sleep deprived and you then go to sleep, there is pressure that builds up that will let you get a lot more slow wave sleep and REM sooner so the idea is well I got an hour and half of slow wave sleep and an hour and a half of REM and then I woke up so I’m fine. That is not a good way to look at it. Yet some people in the polyphasic sleep community which I just introduced a term here, were planning their sleep around that logic.
Daniel Schmachtenberger: Sure.
Dan Pardi: That’s why I mentioned it.
Daniel Schmachtenberger: Fair. We'll come back to polyphasic and bimodal sleep in a little bit because that's interesting but a little bit more foundational stuff to lay down. So circadian rhythms so when we’re sleeping, we’ve got these different actually wait, we should go a little bit further into those phases of sleep, what primarily is happening in slow wave sleep that’s meaningful and what primarily is happening in REM sleep that’s meaningful that we know of with some certainty so far.
Dan Pardi: Yeah, it’s been a challenge to understand. In fact you know what, I’m going to something else. I’m going to introduce a model because this will help to explain this question perfectly. The most cited sleep application ever is from Alexander [Borbey 00:17:00]. He’s a [inaudible 00:17:02] who introduce a completely world changing model called the two process sleep and wake model. What that model basically represents is that during the day from the moment you wake up until the moment you next have an opportunity to sleep, you are building up sleep pressure. It’s a concept right? Building up sleep pressure. What is the physiological neurological correlate of sleep pressure what that means is what’s happening to kind of describe this observation that you get that sleepiness is building.
So we don’t get however if you think about it, you don’t wake up in the morning and get sleepier and sleepier as the day goes on. That’s not how that works. That’s because the other part of that two-part model is wake drive so counteracting this building sleep pressure is a drive to promote wakefulness in the brain that meets it when working correctly perfectly and so what happens is you wake up in the morning and you have this wake drive that matches how much sleep pressure, you have very low sleep pressure and so wake drive is very low.
As the day goes on sleep pressure build but so does wake drive and your sleepiness tends to be pretty even so there are days that you have that are good days and days that you have that are not so good days but you don’t, you tend to be even accept in the afternoon, there’s a little bit of a dip in that wake drive which is why we get sleepy, but then what’s called the wake maintenance zone is the highest activity of your wake activity is between the hours between like about five and 10 depending on when your sleep period is but for a normal person who maintains a normal sleep period.
In fact, that’s one of the hardest sleep during that time so that’s why if you’ve been up for 24 hours and as you continue to stay up, it actually gets easier than it was previously, not harder. It’s a model that’s good to understand and I’ll describe what’s happening with both but I wanted to talk about it because the important thing is what is the sleep pressure and that was very difficult to understand.
In fact, I think while we have really good confidence that adenosine which is a nucleoside that is involved in energetics or the production of ATP, adenosine triphosphate. Now adenosine is then cleaved as energy is produced from ATP and it builds up extracellularly so outside of these cells in the brain, you see this accumulation of adenosine. That is what we believe sleep pressure so there are receptors around the brain. They are perceiving how much sleep pressure there is or adenosine. The way to really understand this is the most famous of all adenosine blockers is coffee.
You might have heard of it listener, so we all drink coffee in this world and we get an immediate boost in how we feel. Now, it’s definitely not the only thing that is determining how awake we are. It's why we can’t sort of over, we can’t resolve all of our sleep pressure from a terrible night’s sleep with just a cup of coffee, there’s a certain amount of benefit that we will get and then it sort of maxes out and we just get anxious after that. That is really important to understand.
As that sleep pressure builds then at night what happens is this wake drive that has been counteracting it all night now dips down. You had this unopposed sleep pressure and that causes you to go to sleep and it causes you to get into deeper stages of sleep. It promotes the activity of slow wave sleep. During the activity of slow wave sleep, it actually will purge or reduce that sleep pressure so you start the day fresh. I know that was a bit complicated. It’s actually a little easier to explain with graphs but those are some really fundamental concepts to what’s happening in this intimate dance behind the scenes that is determining how alert you feel right now.
Daniel Schmachtenberger: So this sleep homeostasis cycle which is the balance of sleep pressure, weight pressure so one of the things that’s happening during slow wave sleep is purging the sleep pressure chemistry.
Dan Pardi: That’s right.
Daniel Schmachtenberger: Now obviously, that’s affecting our subjective experience but the only reason there is sleep pressure chemistry is to make us sleep for other reason. There’s a whole bunch of other physiology that’s happening, memory consolidation, anti-inflammation etc. so coming back to that obviously getting the slow-wave sleep makes us feel less sleepy. What else do we know about the anabolic chemistry, the tissue repair, the immune process, what’s happening then?
Dan Pardi: Yeah. During slow-wave sleep, you also will have the highest release of growth hormone particularly in men than at any other time during a 24-hour period. In fact, most growth hormones released happens during slow-wave sleep. By the time you're 60 for most people, the amount of growth hormone that you’re producing is 15% of what it was when you were younger. That corresponds almost perfectly with the reduction that is typically seen across the lifespan in the ability to generate slow-wave sleep. There’s been this idea that sleep itself actually promoting the aging process because as we have less ability to get into these deeper stages does that then promote less of an anabolic reparative physiology and does that then promote what you see in terms of the loss of muscle mass, sarcopenia, and even the loss of regenerative functions in the brain and the heart tissues etc. yes, probably.
There’s also a bit of danger not to go under a different topic but there’s also some dangers of is it necessarily pathological or is it protective because as you get older, do you really want a lot of growth stimulus and tissues that might actually become more cancerous because of senescent cell buildup etc so we have to be careful sometimes by trying to, as we try to optimize particularly within growth hormones, but yes, this is one thing that’s taking place during slow-wave sleep and that’s one of the reasons why physiologically, you get a really good deep sleep at night and you feel more restored the next day. Your tissues feel better, you ever go to bed, you feel achy and your eyes, you’re just ready for sleep. You wake up in the morning and magically you feel better. Part of that is because of the hormones that are released. Those hormones mostly are taking place during slow-wave sleep.
Daniel Schmachtenberger: I think that there’s a meaningful thing to get into here because HGH dropping with aging, people supplementing HGH, there’s a whole question about is that possibly carcinogenic or not for certain kinds of [inaudible 00:23:38]. There’s a lot of debate around that, not go there for now, but with regard to endogenous HGH from sleep since increased sleep quality and increased slow-wave sleep in particular is associated with decreased mortality from all causes and including a defect carcinogenesis and because a lot of what’s happening with the carcinogenic process, with the body’s ability to have immune cells identify and kill cancer cells and to address the radicals. All of that happens during slow-wave sleep also.
Dan Pardi: Yes, that is also right. That’s a very important distinction that you made is somehow physiologically maintaining higher levels of restorative hormones different than exogenous application of those hormones. I would say the answer is my instinct is that yes it is because the panoply of hormones that are going to be released in response to a good sleep generation are going to be more coordinated than the exogenous administration of one hormone that is important in that process.
Daniel Schmachtenberger: Right, my understanding is during slow-wave sleep, we’ve got the peak in growth hormone and that also means changes in growth hormone, releasing hormone, IGF-I like all of that whole process, prolactin is releasing in a spike, testosterone, androgens are changing in association with decrease in certain cytokines, changes in immune markers inflammation. There’s just a whole complex of things that are associated with increased killing of pathogens, increased disruption of senescent cells [inaudible 00:25:16] apoptosis and increased anabolic regeneration of all tissues.
Dan Pardi: Yes so to talk about the immune system, very interesting work that’s been done there, circadian factors which are these 24, again the circadian system is cycles of 24 hour activity behavior physiology autonomic activity. During when we go to sleep, that will regulate the immune system in our gut when we get and in fact, it will actually turn, it will dial our immune system at times up and it will also dial it down and both are important for health.
When you dial it up too much like you see with sleep loss, you actually can kill off too much commensal bacteria and you can cause dysbiosis. So sleep can cause problems with your gut and intestinal health permeability issues as well. A fish tank is so fragile to maintain, you have to maintain the balance in that water so well for the coral to live, for the fish to live. We are no different. Part of this whole equation is again this importance of sleep topic.
Daniel Schmachtenberger: Yeah, it means why we wanted to do this is one of the early podcast and go deep [inaudible 00:26:39] and kind of theme at Neurohacking all things we can do to affect the mind, brain body interface for all meaningful psychological and cognitive purposes really kind of put sleep in one category and then everything else in other categories because it just this is where the regeneration of the regenerative pathways themselves happens. This is where the homeodynamic processes themselves get upregulated and everything from cell biology and bottom-up genetic processes to top-down their endocrine processes. You couldn’t have picked a more important area to research as far as I am concerned.
Dan Pardi: I have to admit I stumbled into it. I was working at a pharmaceutical company almost 15, 20 years ago. They had the drug Sodium oxybate or GHB for narcolepsy. To make this point quickly, because of that I found myself in the sleep field. I very quickly realized that understanding sleep and to research it, to evaluate it is an incredible window into the body. You sometimes can think of it in sort of an encapsulated fashion. Oh it’s sleep. It helps you understand how the entire body works and therefore it provides a lifetime of interesting challenge to understand how the body works.
Daniel Schmachtenberger: Just a few more things in terms of addressing some of the physiology of sleep deficit in particular, meaning not getting enough sleep or not getting enough quality of sleep so when we talk about sleep deficit associated with inflammation and cytokine changes.
Dan Pardi: Yes, yes. One of the most sort of important factors to health is a chronic state of inflammation, inflammatory state, why is that? Well because it creates a toxic environment when we have things that perturb our internal physiology the results of which is an elevation amount of circulating cytokines or inflammatory markers. Sleep itself is a stressor so as you go into the different stages of sleep, the body will, there’s a huge dance it’s hard to even know where to start imagine like the spaghetti chart where there’s all different things happening but in response, you have a decrease in your autonomic nervous system activity particularly the sympathetic nervous system.
Downstream of that, you have activation of your adrenal cortex so you have a decrease as a dance in cortisol so in fact this sort of dance that’s happening in the brain is superior to the entire neuroendocrine system so what happens downstream? All those hormones are being controlled by that physiology that’s taking place in response to sleep loss or excuse me in response to sleep initiation in the sleep process. When you don’t get enough sleep, your body perceives that as another stressor. What this can lead to is a heightened degree of circulating inflammatory factors. What does that do? It does a lot of things in the body one of which is to create cortisol resistance.
If you’re constantly having too much cortisol circulating in the body then the tissues, wait what does cortisol usually do? It dampens down inflammation. What happens when your cells become resistant to cortisol? Well you actually have increased levels of circulating inflammatory factors. This can lead to conditions that look like Cushing’s syndrome where you start to develop abdominal obesity. It can lead to cognitive issues, brain fog so we have incredible ability to withstand many nights of imperfect sleep. If your pattern of living described by inadequate disrupted imperfect sleep then whether it’s because of your own doing or because of a sleep condition that you have, that is going to really cause a major acceleration of the aging process, the disease process and the diminution of your ability to think robustly for whatever capability you have.
Daniel Schmachtenberger: I'm just looking at the inflammation dynamics. Obviously there’s a lot of other dynamics we can look at regarding hormones and EEG patterns and memory consolidation but just inflammation. I was fascinated some of the research of how little sleep deprivation is required to raise CRP which means increased heart disease and cardiovascular risk and just within a couple hours of insufficient sleep, we got elevated TNF alpha elevated IL-6, TGF beta and it’s like that means increased risk of almost all kinds of autoimmune neuro degenerative cancers. That’s kind of like a profound thing to realize. If someone is wanting to prevent pretty much all chronic diseases then decreasing level of circulating cytokine is critical thing. It’s probably the case that adequate high-quality sleep is the most effective thing we know across all of those different pathways.
Dan Pardi: It is a really fun intellectual question to address and at the same time when I've thought about as I describe physical activity and diet and sleep as imagine a chair and imagine that each one of those components is the leg of a chair and then I say okay which leg is most important for the functioning of this chair. While I actually agree that it is one of the most actionable important elements to our health and to the quality of our life, we’re going to get in some pretty interesting details, I know I'm sure.
At the same time some people will get great sleep and then not get enough physical activity. [inaudible 00:32:38] terrible. Every different permutation or combination of that can happen. Each one of those independently can cause a chronic state of inflammation and so the nice thing about sleep is think about the difference between sleep and food. I often say I love my job because I'm telling people to do something that they love. Go get a great night’s sleep, who doesn’t love that? Versus don't eat the ice cream or insert your whatever highly palatable food that you love that you can overdo easily.
It’s a different sort of quality and yet it still has its own challenges. The challenge now the equivalent to the ice cream is don’t stay up and watch another episode of Game of Thrones and yet it is extraordinarily compelling to when that is your free time, that’s when you get actually do some of the things that you love and to dial back on that is really hard particularly also to know that for example TV watching can alert you so you don’t really feel sleepy so you just stay up until you actually do feel sleepy but if you were in a natural environment sleeping out on the tent if anybody goes camping and you fall sleep sometimes an hour and half before you usually do, you know how our environment can sort of coercively get us to do things that are unhealthy just because it tricks our physiology.
So I just sort of segued into some of the things that matter for good sleep but I wanted to say that this is in terms of sleep is extraordinarily important and yet it’s a great opportunity the way that I like to think about it is getting good sleep helps you do everything else well because it increases your capacity to do that to live in accordance with your own ideals for actually being healthy which means eating well, getting physical activity, performing well, so yes I think you can make a really strong argument that sleep could be the most important one of them. Yet at the same time, you could take the other side of the coin and say they’re all important. Sleep is absolutely necessary for long-term health and performance.
Daniel Schmachtenberger: Necessary but not sufficient.
Dan Pardi: Yeah.
Daniel Schmachtenberger: I was actually about to say something related to that so I’m glad you brought it up which is even though we like to think of the buying terms having this regulatory processes where it will lower things to get too high and raise things to get too low which is true. It can also have places where it gets into virtuous or vicious cycles and where you get kind of runaway feedback processes so inflammation and sleep is one of those interesting ones where sleep decreases inflammation and then lower inflammation makes it easier to get better quality sleep.
One of the causes of poor quality sleep is inflammation which decreases how deeply one goes into slow-wave sleep etc. and so someone eating inflammatory foods or anything other physiologic dynamics that go on that cause inflammation toxicity pathogenicity can damage sleep quality which then in turn damages one’s ability to address that inflammation so I think that’s a kind of classic example of where we really want to do everything it takes to get out of a vicious inflammatory cycle with sleep and other things and into a virtuous one.
Dan Pardi: Totally and I’ll mention that the effects of immune system on sleep are dynamic. One other correlate for sleep pressure is TNF alpha not like adenosine which accumulates extracellularly as the day goes on from energy usage. We also see an increase in TNF alpha. That is sometimes it's easy to describe aspects of healthy physiology as only bad not to say that you are doing that but for example cholesterol, bad cholesterol, good cholesterol so does bad cholesterol should we just get rid of it altogether? Does it have sort of physiological purpose? And then there’s also the difference between acute issues of getting one night of bad sleep to chronic. What happens over long-term usage or a long-term condition?
We do know that with one of the reasons why we’re more sleepy when we’re sick is because of immune factors that actually promote sleepiness. One of the reasons why people would have chronic sleep, other sorts of inflammatory conditions, the immune markers themselves can disrupt the sleep and so it depends on the balance. It’s almost like exercise, a little bit of exercise relative to how much you get can make you sleep really well and then too much can actually disrupt your sleep. There’s that U-shaped relationship manifests itself in so many different ways in our physiology. Immune markers is one of those ways.
Daniel Schmachtenberger: We have just touched on, we've talked a little bit about the effect of sleep on physiologic dynamics that affect disease. This is also relevant to aging but why do bodybuilders make sure to get enough sleep? We haven’t talked about anabolism that much yet.
Dan Pardi: Yeah well one of the really important things that a lot of young bodybuilders need to learn the ones who do make much better gains is that you don’t grow by providing the stimulus in the gym. That’s where the stimulus for growth is provided. You grow or you build your muscles in response to that stimulus when you give it the right nutrients and when you let the healing process happen. People that take anabolic steroids for the purposes of bodybuilding they can induce a condition where they can grow faster and they can train harder and more regularly.
You’re kind of artificially inducing that anabolic environment for the vast majority of people who are physically active and lifting weights who are not taking anabolic steroids then you need to create the right situations to allow for that healing to happen so that the hard work that you’re putting in to the gym pays dividends in terms of growing muscles and having joint tissue repair, having fibers tissue repair and having of course the muscle tissue repair. That sort of dance of the 24 hour different cycles of hormones is there are so many other necessary for that again the healthy functioning so yes adequacy of sleep time and good non-disrupted sleep is critical and that’s why but also the things that you do during the day are also really important in order to get good sleep too.
Daniel Schmachtenberger: So then we’ve addressed some of the physiology, what can we say about the effects of adequate sleep or inadequate sleep on the psychology and cognitive capacity?
Dan Pardi: Yeah, so I’ll start with some cognitive capacity and then we can move into some of the psychology. This is the area that I actually spend more time with now. My interest in sleep is vast but I decided to focus on looking at the interrelationships between sleep behavior and eating because obesity is such a massive, massive problem that can bankrupt the world in itself of the cost burden and the suffering burden as well with having obesity the risk for your risk increases for over 50 other disorders and one thing that people don’t often know is that fat tissue itself is an exocrine gland.
It releases hormones into the bloodstream most of which there’s now 50 different substances that have been identified that are released from fat tissue, the vast majority are inflammatory. One way to become more inflammatory is to carry an excess amount of body fat. At the same time well that can actually disrupt your sleep. Poor sleep increases your risk for being obese by about 55% according to some estimates looking at-
Daniel Schmachtenberger: Wait, I think people should hear that again.
Dan Pardi: Yeah so study that was done by Karen Spiegel looked at, showed that, one, out of perspective longitudinal studies, 81 out of 89 studies that look to see if there was a connection between reduced sleep and body fat showed that there was a positive finding. If you pulled all of those, your risk for obesity is increased by 55% when you’re getting inadequate sleep. To a degree, a sleep level to a degree that is common in our society.
Daniel Schmachtenberger: An hour per night less than one should have give or take.
Dan Pardi: That’s where you start to see that the risk becomes elevated. That was sort of the genesis of my interest going back to the cognition but as a result of that, we want to understand what’s happening in the brain that is then affecting competitive behavior or appetite. One thing that I have been very interested in and one of the most well understood, well-documented effects of sleep loss is a disruption in your intentional networks or your ability to focus on anything in your environment so think about ADHD, Attention Deficit Hyperactivity Disorder, Attention Deficit Disorder.
If you think about what attention is, it is the ability to filter out information in your environment so if you think about your perceptual field and you want to look at this car that is coming for you. Now that doesn’t mean that you can’t see the bird that is flying overhead to, that is in your perceptual field but you want the ability to filter out information that the brain is determining is not important and to be able to focus, sustain your attention on the information that is.
Now a lot of it it’s a lot easier if it’s a car coming for you. It’s a lot harder when it’s multiple browser tabs open and it's less, there’s just a lot to focus on so what is happening with attention? Well attention is mostly driven by this frontal parietal networks so your frontal cortex, your parietal cortex and the functional connectivity that they maintain. What happens is you see that during sleep loss, typically if you look at fMRI, functional magnetic resonance imaging, you see very strong functional patterns where parts of the brain will work together to perform activities.
You have, now when you're trying to focus on something then the frontal parietal cortex is strongly activated and strongly connected. They're working as a functional unit. Then you have a different type of attention which is your resting state brain. You’re still alert but you’re not necessarily focusing on a specific task so this is something called the DMN which is the default mode network.
The default mode network is sort of thinking it’s like subconscious in a way. It is keeping you alert while you’re awake but it’s not necessarily focusing on something specific. If you’re walking down the street and you’re sort of talking to yourself, that’s the default mode network which is active. Similarly under sleep loss, the default mode network has well actually the basic function of it is that these different areas of the brain that make it up, it’s not just one anatomical structure, it’s different parts of the brain that work together. They lose their connectivity to one another. They don’t function as one unit as well.
What happens is that you don't clearly see. If somebody is asked to perform a task in a computer while their brain is being imaged after a night of total sleep deprivation, you don’t see a very clear default mode network or frontal parietal network being activated. It loses sort of that connectivity that is so critical. That leads to behaviorally, that leads to the situation. If I were to say look at that cat. You could look at that cat, you just couldn’t sustain your attention in that cat very long.
You can’t sustain your attention on something for very long because you have instability in this network. You have intrusions of other parts of the brain that usually don’t intrude and what ends up happening is that all of the stuff in your perceptual field becomes harder to filter out and harder to pay attention to. It can lead to a very frustrating day of nonperformance and in the world of eating and behavior, food behavior, it can also lead to making all sorts of interesting and non-helpful decisions.
Daniel Schmachtenberger: You said harder to filter out and harder to pay attention to which is a key thing because we are taking in many orders of magnitude more bits of information that we can consciously focus on. So specifically reticular activating system has a lot to do with what’s actually relevant and making sure that we’re consciously registering what’s relevant as understanding that as sleep pressure builds specifically as adenosine elevates in the forebrain and glucagon decreases in the forebrain, reticular activating system is one of the first things affected.
Dan Pardi: Actually, the frontal parietal network is far more sensitive to sleep loss and sleep pressure, the subcortical thalamic brainstem and basal ganglia which are generating this sort of the arousal which is a very important part to attention. Those are actually more affected by circadian factors so if your sleep timing is way off then that reticular activating system and all the different components that make up that arousal system are going to be really, really affected.
In one case you might have if you have good sleep timing but inadequate sleep time so you went to bed at midnight but you didn’t wake up at 8:00, you woke up at 6:00 or 5:00 then your arousal network might perform better but your frontal parietal attention network is going to be really affected by the remaining amount of adenosine that’s there, anyway, the result of which is going to be poor performance and focus and stability.
Daniel Schmachtenberger: We did some testing with people on various degrees of sleep deficit not even that much I mean a half hour less than what they would have needed to wake up feeling refreshed in terms of things like CNS VS, their verbal fluency there’s cognitive metrics and verbal fluency starts dropping very quickly word recall.
It was interesting to see how many things were affected by sleep. One of the things like with quality is we were doing our quality studies that we found is there were some percentage of people that were not responders, they just didn’t really have a response. When we look to see if we can find any pattern, there were two patterns that really showed up, people with IBS or IBD like they had G.I. issues absorbing nutrients might be difficult and people who had sleep issues and across the board, people who aren’t getting Delta sleep had a hard time responding because a lot of the chemistry we were driving was involving memory consolidation and acetylcholine pathways that are really mediated in slow-wave sleep in particular so then trying to drive more chemistry through a pathway that is not actually getting its process and repair gets kind of rate-limited.
Dan Pardi: So you brought up something when I talk about attention, the other cognitive domain that functions almost in unison to flagging attention is working memory which is a component of executive functioning. That’s the ability to hold multiple things in your mind whether they're present or not and then to juggle and balance and decide. It’s like your mental whiteboard. That also is really severely impaired.
One thing that’s very challenging with cognitive neuroscience is task impurity. We think we we're studying something specific and there’s been a lot of attention that's gone into, does this task selectively look at executive functionings or working memory or that working memory component of executive functions etc. etc. It’s important to be able to do that but it’s also we know that your executive functioning and your working memory and your ability to retrieve and then also maintain in that memory to actually use that information is also severely affected by low arousal and imperfect attention, so yes, it’s important to look at them individually and yet at the same time we know that these different components are all working together ultimately.
Daniel Schmachtenberger: Network effect.
Dan Pardi: Yeah absolutely.
Daniel Schmachtenberger: We can say I mean there’s a many things but sleep deficit, sleep issues, cognitive effect is huge and psychological effect, there’s some very interesting studies on depression, anxiety and even psychotic episodes for the severe no sleep deficit.
Dan Pardi: Yeah and sort of related or maybe transition but since we are thinking about sleep pressure we just talked about sleep pressure which is adenosine. We can think about it that is probably other things too but that is having a significant impact on the frontal parietal cortex which is helping you with being able to focus. We also know that an increased adenosine load will trigger a down regulation of dopamine to a dopamine three receptors and what does this result in? It results in less expression of these receptors in the stratum.
Then you also have decreased because adenosine is blocking these receptors, you have an increased ratio of dopamine one receptors to dopamine D2, D3. I know it’s pretty technical but what is the sort of results of that. It actually leads to increased risk related and reward related approaches to behavior. This is why casinos make most of their money late at night. If you think about what a casino tries to do, they have, you artificially stimulated by the environment, they have you artificially stimulated by light and they're giving you just the right amount of alcohol, not too much, sometimes free disinhibiting and you end up having the economic preferences that are calculated in your brain about risk and reward become totally skewed and you end up because of this chemistry that I just mentioned, you end up doing things like overvaluing or overestimating your potential to win so if I put this much down on this hand, I could win X fold more and.
Now that is typically balanced with part of the brain that is saying yeah but you could lose $500 or 50 bucks or whatever it might be. Well it turns out that under sleep deprivation, you have the sort of optimist bias where you focus much more on what you could win and much less on what you could lose. If you think about out of a gambling situation, there’s a lot of bad things that can happen when you you're not focused on consequences.
If you carry that through to the day and you’re to sort of extrapolate that information and think well in a sleep deprived state which you are somewhat alerted with those economic preferences still shift and thinking about in the food context, that might mean that you’re much more likely to focus on the taste of the cookie than actually the risks of eating that cookie and adding to your waistline and poor health.
It’s really, really interesting to look at what happens in gambling tasks and I think about how is this relevant to all sorts of things in life and that’s a I think a very interesting example. Another one not only with obesity but also with alcohol behavior as well so we see that a lot of times people that are alcoholics will drink because they think it’s going to help them sleep. The reality is is that people that have insomnia have a much higher rate of recidivism going back to drinking than those who don’t have insomnia and so there’s definitely alterations in this reward processing that’s taking place and those are just two of those mechanisms or two of the different conditions that you see, obesity, promotion and addiction promotion.
Daniel Schmachtenberger: Is it worth just mentioning briefly orexin and ghrelin and the effect that happens on them during sleep deficit?
Dan Pardi: Yeah more so in orexin so ghrelin is I’ll explain what that one is first so orexin is also referred to as hypocretin and that’s because it was co-discovered meaning one lab in Texas discovered it, another lab at Stanford, Scripps discovered it. The person who discovered it moved to Stanford. That happens all the time and so forever now you will see papers that talk about orexin and in parentheses it says hypocretin.
Anyway it’s a very important compound in the brain. It is released by what are called parafornacles or around in the hypothalamus around the fornix, there is a small group of cells maybe 100,000 neurons that are releasing this peptide that is essentially orchestrating the entire wake network. It is telling all the different systems in the brain that are involved in keeping you alert when you should be, it tells them when to be on, it tells them when to be off.
Now the best way to think about this is people that have narcolepsy are missing orexin or hypocretin and so if you think about what their sleep and wake behavior is like, they’re more like a cat. They can’t consolidate their sleep into an eight hour period. They can’t consolidate their wakefulness into a 16 hour period. So instead, they’re up for three hours, sleep pressure builds and when sleep pressure gets high enough then they have to sleep. They don’t have an ability to orchestrate consistent wake behavior behind that. It’s all dependent on that sleep drive so people that have narcolepsy don’t get inadequate sleep if they were in the right behavioral context where they could just take a nap when they wanted to.
They have the ability to get eight hours but it’s just separated over the course of the day. That makes it very difficult to maintain a job, social relationships etc. so they tend to be very, very sleepy because they don’t get adequate sleep and they're trying to be up during the day when their … or they can sustain their wakefulness for a certain amount of time. It's also interesting that you mentioned that because it is involved, it has functional dichotomy and that part of the neurons, these hundred thousand neurons are involved specifically in this wake generation control.
The other part are heavily involved in reward processing so one of the value of hypocretin is to translate environmental signals that are happening whether it’s light or other things into physiologically relevant behaviors and so the coordination process again between what’s happening around us to what’s happening inside of us is beautiful really.
Ghrelin is also involved in reward process as well. I won't go into it too much but it is oxyntic peptide that is released from the gut so the gut will release this peptide and it is the only gut derived peptide that promotes feeding. All other gut peptides are actually will suppress appetite whether it’s Cholecystokinin or GLP-1, PPY all of those that are released from some part of the gut are helping to suppress appetite. Ghrelin is released in what's called episodic fashion.
As you take in a meal, time goes on, ghrelin starts to rise and you get hungry again. Turns out relevant is also very involved in reward and so ghrelin and orexin actually work interestingly together to promote palatability and reinforcement of food so if you have something like ice cream that you love and it’s energy dense, if you were to disrupt that pathway then the reward effect is significantly reduced. There are some drug companies that are looking into trying to establish whether there is a way to block part of that process but it’s always a little risky to me to think about although it’s possible there could be something there.
Daniel Schmachtenberger: Yeah specifically thinking about the studies that show ghrelin baseline elevates under sleep deprivation.
Dan Pardi: Yes.
Daniel Schmachtenberger: It makes sense that of course if someone doesn’t have enough energy from actual sleep regeneration that they create exogenous energy in the form of sugar calories.
Dan Pardi: Yeah. So one of the most interesting, [inaudible 00:57:46] did some work where they kept people under 88 hours of sleep deprivation and that was around 2000, 1999, 2000. This is working with David Dinges and some others and what they found surprisingly is that leptin levels went down so leptin, people most often think of leptin and ghrelin in the same sentence because they’re sort of doing counteracting activities. Leptin is a fat derived peptide that would travel with the brain to signal how much energy we have on our body.
When leptin levels go down, that tells the brain oh there’s a deficit in energy and the brain responds by doing a variety of things. It turns on anabolic processes. It turns on goes down [inaudible 00:58:32] that is trying to conserve because it's trying to get your weight back up. It is a physiologically, your body fat is a physiologically regulated parameter. That’s what leptin does and what sleep loss does is it causes leptin levels to go down. That independently would make you think that you would eat more the next day.
Separately, ghrelin goes up and that just as I described makes you hungry so there’s two different things that are happening simultaneously, leptin going down, ghrelin going up in response to sleep loss that are both promoting more food intake the next day. Some really interesting work that’s taken place is question whether this is actually relevant because energy expenditure is greater when we’re awake and so if you were to let’s say spend four more hours awake by undergoing partial sleep restriction so instead of going to bed at 8:00, you went to bed at or excuse me getting eight hours of sleep, you only got four then you’re going to be expending more energy even if you’re sitting there versus sleeping.
Could that excess energy expenditure then lead to are these hormonal differences really just reflective of that energy difference? What they found is actually yeah so this is some work that was done out of Colorado and Kenneth Wright’s lab. What they showed us that those hormone differences are what you’d expect but it still changes eating behavior so people that then undergo sleep loss at the end of the day, they end up taking in a lot more calories later in the evening the next day. That can promote weight gain. That made people wonder okay is it these hormones or is it another hormone that’s involved in weight regulation or is this something else that's happening in the brain that is shifting how we process reward that is making us seek out foods, it's how we process reward and actually how we control that reward with our cognitive control areas and so obviously there’s a big interplay that's all going on here.
They are all involved but the story that has taken place has been very interesting because you find a little signal that something is going on here. First you look at the epidemiological connection, yes, the connection is strong then you try to understand what’s happening endocrinologically yes, you see these alterations in endocannabinoids, you see alterations in leptin and ghrelin. Now how is that having an effect on energy expenditure, nothing too different there that would describe this but what’s happening else in the brain yes definitely changes how the brain is operating the next day and a lot of these changes happened beyond our awareness. Sometimes you can recognize them and sometimes you just can't at all. You just all of a sudden say screw it, I’m going to eat that thing that I’m trying usually not to eat, that happens it’s called effort discounting. You're just much less likely to make an effort toward something that you value when you’re in the condition of sleep loss.
Daniel Schmachtenberger: Which when you think about how many people feel just tremendous frustration with themselves regarding their own failures, how many things that they want to avoid and then they end up doing it and they hate themselves and it makes no difference to not being able to avoid it whether we’re talking about food, things or TV or porn or any kind of behavior that is [inaudible 01:01:57] someone wanting to shift to realize that sleep really has a kind of foundational role in one’s ability to actually make choices and both make good choices in the first place and follow through them is a big deal for anyone who wants to shift that dynamic. Obviously again necessary but not sufficient, but necessary.
Dan Pardi: Yes, yes absolutely necessary, really good point. A friend of mine that I've tried to help with weight regulation over years is a brilliant guy programmer [inaudible 01:02:28] lady gets into the zones where he codes, codes, codes until four in the morning he’s starving because he hasn’t actually eaten 16 hours and he orders Nazario’s pizza and consumes 3 to 4000 calories literally at the worst time that you could. That’s a whole other subject when the body is taking in calories and everybody is ready to take in calories at that time. He would beat himself up, he would make all sorts of not so great decisions by the virtue of his lifestyle and part of it was and it hurt him psychologically because he thought he was a failure. He thought he didn’t have any self-control. He’s a very smart guy but he had really bad sleep hygiene really bad sleep hygiene.
Daniel Schmachtenberger: Okay so we’ve discussed that sleep is relevant for lots of things like critically relevant for most everything that matters psychologically, cognitively, and physiologically so then we've been kind of referencing terms. We haven’t defined we were just discussing when should someone be eating and when should they be sleeping. So quick overview, what our circadian rhythms?
Dan Pardi: Yeah so these are repeatable 24 hour processes pretty much every organism from single cell organisms to mammals have repeating behaviors whether it’s cell cycle, growth and repair processes whether it’s when you feel like going to the bathroom and when you feel like eating to when sleep is occurring and when wake is occurring. This is mostly orchestrated through one process which is light coming into the eye. We have receptors at the back of the retina. They’re called intrinsically photosensitive retinal ganglion cells. They were discovered in the mid-90s so we know we have rods and cones.
Those cells clearly will help us see light and color and what they do is they’ll transduce photons of light that come into the eye and they turn into a nerve signal that goes back to the visual cortex. In the mid-90s, cells that have the same capability to transduce light into a nerve signal were found but these don’t go to the visual cortex. Instead, they go to via something called the retinal hypothalamic track eventually to the suprachiasmatic nucleus which is the master clock in the brain.
This master clock is keeping time. What time is it? Is it afternoon, evening, night? Then downstream of that, we have clocks throughout our body in every tissue in every cell and so that master clock is orchestrating the timing of the activity in those cells as well. Those can be decoupled peripheral tissue and the master clock and bad things happen when that does happen. That's why eating late at night can actually be really problematic. I just wrote a blog about this recently.
The discussion is currently taking place on my blog with other people that are chronobiological experts all about the subject but it’s really, really important to our health for many different ways, how well our brains are functioning, how well our arousal system is functioning and light is that key component there. What matters with light? Well it’s the intensity of light. It is the timing of when you’re getting light, it is a spectrum or the color of the light.
All of these things matter in terms of the signal that the brain is getting. We have now things like 90% of us or most of us spent 90% of our time indoors so we’re not getting a very strong light signal from outside. We have no idea of how seasonality is affecting human behavior but we know that there are certain seasonal animals which light completely changes their physiology at certain times of year to then predispose them to gain enough weight for winter. We also have artificial light so if you think about it we’re getting much less intensity of light during the day because we’re indoors.
Even though the light is totally adequate doesn’t necessarily look like it’s not very strong. It’s orders of magnitude stronger when we go outside. The other weird thing is now as the sun goes down, we have those same artificial lights that most people [inaudible 01:06:40] same intensity and so now we’re getting a lot less darkness. Not only are we getting much less light intensity, we’re getting a lot less darkness. Now what happens under darkness? We have something called dim light melatonin onset which produces melatonin which essentially reinforces to that master clock that it is nighttime so raccoons which are nocturnal they have high levels of circulating melatonin as well.
It’s not necessarily a sleepiness hormone. It does promote some [inaudible 01:07:12] or sleep inducing activity but that’s why you tend to see people have to take a lot of it in order to feel sleepy. That can cause some problems but what it does more is that it tells the brain this is the time of day that it is. That will affect the inner workings of that master clock but it also has an effect throughout the body as a powerful antioxidant in your gut throughout the body and so one big problem I think in our health is not only that we’re getting inadequate light and weird mistimed lighting environments but we're just living in a lot less darkness than we used to.
Daniel Schmachtenberger: All right so you hit on so many things that are interesting there so we have circadian rhythms where the body has different processes that are optimized at different times. Obviously, sleep and wake is the primary thing that we’re identifying because it’s evolutionarily relevant to be able to be awake and cognitively clear and physiologically responsive and then to be able to rest adequately and deeply.
Obviously the basis of that was that we live on a planet that does this 24 hour sun cycle thing so photoreceptors really regulate the circadian rhythm that then also regulates when we should be eating and if we’re going to digest our calories and all that other stuff. Now you mentioned the photoreceptors that are in the retina but we have photoreceptors in other parts of the body that are relevant. I’ve seen some studies that were done in sleep labs where people were in complete dark so there’s nothing hitting the eyelid.
Then light was shown on the skin with a penlight so it didn’t enter the room at all while cortisol is being actively monitored in the blood and cortisol started to elevate just from photoreceptors and skin which is very interesting because it means that again if people are sleeping in an environment that’s not dark enough even if they have a sleep mask on, they’re going to be sleeping subadequately.
Dan Pardi: Yeah, that’s an interesting point because I often will tell people if you’re lighting environment is not ideal, you can sleep with a sleep mask and that’s going to help because our eyelids were also translucent which means that light can go through them and affect our circadian system even though your eyes are closed and you’re sleeping.
In fact it’s technique you can use for teenagers that have this desire to stay up later, delayed sleep phase syndrome that you can actually help to dial their sleep timing back a little bit and their wake timing so you have a light alarm that wakes up, goes off at 4:00 in the morning the child sleeps through it, the light enters into their eyes and it pulls because the timing of light really matters. A good example is if I pick up today and I fly to Italy then [inaudible 01:09:54] my physiology is going to be completely synchronized to San Francisco still.
When I arrive there, the timing is going to be completely off, completely flopped over the course of days as light is enter as I try to maintain a normal schedule there, my physiology will completely reset so think about that timing of light really matters both if you’re getting a lot of light or before going to bed but also before you wake up and that technique can actually be used to help people that ordinarily have a really hard time waking up get up earlier and then want to feel like they want to go to bed earlier and a common problem for some people is that they desperately want to go to bed early, they’re so sleepy all day and right before bed, they're the most alert that they have been all day. It's extraordinarily frustrating and that has to do with the timing of their circadian rhythm and that’s one technique that somebody can use to influence that.
Daniel Schmachtenberger: So what is it that when people are in sleep environments that are underground complete light control so there’s no relationship to sunlight and they’re in either constant dark or constant light, that they have a slightly longer than 24 hour circadian rhythm. The 24 hour rhythm has to be continuously adjusted by light exposure. What is that from?
Dan Pardi: Yeah it’s a really good question because it unveils some important points about the circadian system. The length of your circadian rhythm is called your tau and left to its own devices without external stimulus. A lot of people can have a tau that is 27 hours instead of 24, 29 up to 30 sometimes shorter, mostly longer and so without getting adequate light, your own rhythm, your own 24 hour rhythm can elongate and that can really lead so let’s look at a couple things here so the timing of that rhythm can elongate but it can also then shift so elongate and it can shift.
All of those can mess you up in terms of how well you feel the next day and how well your physiology is performing, how well you’re recovering so yeah, you’re right if you’re living in constant darkness, this is some of the earliest work that was shown here. They showed that when people don't have that external stimuli if you left somebody in that condition for weeks and weeks at a time, you could have started off where your 8 AM was their 8 AM because you start off in the same rhythm but weeks later, their 2 PM was your 8 AM because their timing had completely shifted or excuse me their 8 AM was your 2 PM. It’s completely shifted and elongated so yeah so that’s important point to mention that we need light in order to maintain healthy timing and healthy tau.
Daniel Schmachtenberger: Now when you talk about needing light so obviously light suppresses melatonin and increases cortisol to regulate that primary circadian rhythm that primary kind of hormonal circadian rhythm cortisol melatonin and antagonistic relationship but everyone also knows that vitamin D and sunlight have some major things to do with each other. Anywhere on the skin photosynthesis of vitamin D and not just vitamin D but whole aspects of the vitamin D process, vitamin D, I mean proteins and receptors are stimulated by sunlight but nitric oxide is affected by sunlight. We’re actually photosynthetic creatures that do lots of things. ATP is upregulated by near-infrared light and so it’s pretty fair to think about I think that we have a whole set of photic nutrition. It’s like we need a bunch of different nutrients. There is intensity and ranges light that’s actually necessary to do a lot of aspects of our physiology.
Dan Pardi: Yeah that’s an important point too. The tone of light changes across the day. We have dusk and dawn is very different than high noon and speaking about needs for light, the need for the absence of light so we need different tones, we different intensities and we need absence, all of it. I never heard that term before perhaps you made it up but that sort of photic nutrition is a cool way to put it and it’s absolutely true.
Daniel Schmachtenberger: I’m curious to your kind of philosophical musings on something. We think about before artificial lighting so let’s say obviously it depends upon how far people were from the equator and what time of year it was but let’s say that on average we’re looking at 12 hour light and dark cycles. People were in a lot more dark than they are now. They also were in a lot more light. They had lot brighter light during the day like you mentioned orders of magnitude more lumens outside than inside and so their cortisol went a lot higher but then left over at night.
Their melatonin got suppressed a lot more during the day but then came a lot higher at night like they had actually just a more intense circadian rhythm and to try and make our light more efficient, we take all the near-infrared out because that just is producing heat, not producing light but that’s the part that actually stimulates ATP production and cellular energy and there’s lots of it in the sunlight which is why it’s warm so like just totally different.
Daniel Schmachtenberger: Totally.
Dan Pardi: So not only do we get more light during the day but we had more waking hours that were in dark and of course that meant we’re going to fall asleep better at night but maybe we have a little light like everyone was around the campfire, this is very dim, no blue light in that spectrum. We think about effect of it on our psyche, on our cognitive dynamics and so melatonin is made from serotonin so you’ve got increased serotonin with the dark and just very different cognitive state. People kind of know when they’re out camping and there is no artificial light and they're hanging out around the campfire.
There is like psychologically different states that are less productivity oriented and maybe more being and interconnectivity oriented. I’ve heard indigenous cultures talk about the more time they spent on dark was really key to having increased dreamtime awareness which meant introspection, connectionship with each other, biosphere. You have any thoughts on maybe effects on psychology across whole populations not having that.
Daniel Schmachtenberger: It is such an interesting question and one that I think we don’t even have anything more than sort of hypotheses to understand. Although we can extrapolate from what we understand about again seasonal animals. It’s very likely that if you think about it, fire has been argued to be a part of human evolution anywhere from 800,000 years ago probably more likely starting around 350,000 years ago. That was probably daily for every single person that lived on the planet.
We also know that 99% of our time on earth as hunter gatherers, our physiology was shaped by this light dark seasonality, how that would change. Most of those people were somewhat equatorial, sub equatorial and now we had these great migrations. I just got back from Iceland a couple days ago. It was 24 hours of light. I’ve never been in that situation before, it was really interesting. That was the first challenge to our physiology 24 hours of darkness, 24 hours of light depending on the time of year. But now those are still much more subtle compared to I think holding screens, living in light, turning on the bathroom light.
One flash of light can have a very powerful effect on your circadian timing so a simple thing that I would like to stress as we’re talking about light and I’ll go back to some of the big picture ideas but it’s too important not to mention if you have a young baby, their circadian system is not fully developed when they are born and it continues to develop for at least six months out of the womb getting cues from the mother and also having that developed from the exposure that babies go to.
So what happens, well babies need to eat in the middle of the night go into the room, pick up the child, turn on the light. That can really mess up their circadian rhythms. We know the children that are incubated in ICU because they were born prematurely have drastically increased risks of croup disease later in life, fivefold increases. We’re just beginning to really appreciate the effects of lighting on our physiology from birth to its development to different times in our life to later where we develop cataracts and that filters the blue light that’s coming into our eye and so what happens to the circadian cycle of older people? It shifts backwards.
They want to eat earlier, go to bed earlier, wake up earlier more fragmented sleep over the course of the night. I’m going to be giving a talk at AHS, the Ancestral Health Symposium in a month looking at hunter gatherer sleep patterns. I look forward to diving into the literature this month but yeah to go back, I don’t think that we really know the impact of how light is fully affecting our physiology. We know that like you said red light can have an effect on mitochondrial biogenesis. We don’t get a lot of red light these days. We don’t get a lot of red light during dusk and dawn like we used to well what happens though if you get a certain amount of it so one is the amount that you get and the other is the timing.
So let’s say yeah well I want to get my red light exposure but you get in the middle of the day. Is that an abnormal signal for your body or do you actually need it during times where your body thinks it’s dusk and dawn. There’s just a lot of questions that still need to be addressed. I’ll give you one clear example, the Syrian hamster is a seasonal animal and I was mentioning this slightly earlier but when it becomes fall and the tone of light changes and becomes more red and dim, there's more darkness that will initiate this process and the process happens where you have decreased [inaudible 01:20:35] signaling in an area of the brain called ventromedial hypothalamus and as a result just by light changing it will promote a state of metabolic syndrome.
You have increased triglycerides, increased fat accumulation, alterations and cholesterol levels. All of this has a purpose. The purpose is to have the animal gain as much fat from the food that's still available for a period where their food is no longer available and that helps them stay alive during the winter months. Are these sorts of processes happening to us? We consider ourselves not to be seasonal but we really don’t know. We’d have to really study hunter gatherers and this question specifically and that's just not the [inaudible 01:21:19].
Daniel Schmachtenberger: Next time not this session but when we go to on to more advanced topics talking about near-infrared light therapy, low level laser therapy, transcranially adjusting with jet lag using light therapies, light in the ears and intranasally, all those fun things. We'll dive in to some of those neurotech topics because it’s interesting also as far as chronobiology I think I’d love to dive into the biphasic sleep and polyphasic sleep especially since you said you’re diving into those topics getting all asleep at once versus having our sleep broken up. I’m curious just on that topic quickly though chronotypes night owls, morning birds some thoughts on that being genetic or induced for other reasons.
Dan Pardi: We should save that for the next talk because it’s totally relevant to hunter gatherer biphasic sleep.
Daniel Schmachtenberger: Yeah somebody had to be awake all the time protecting the tribe.
Dan Pardi: There's some interesting research that just came out on that. All that will flow together well.
Daniel Schmachtenberger: Alright good so let’s talk about applied things for people. So people were wanting to … We've talked a little bit about effects of sleep on psyche, cognition and physiology some of the underlying dynamics of sleep so what are some of the main reasons that people either sleep poorly or have a hard time falling asleep or not enough. Let’s start with that.
Dan Pardi: Yeah so 50 to 70 million people in the United States have some sleep disorder. Sleep disorders range from restless leg syndrome, obstructive sleep apnea, central sleep apnea, narcolepsy, multiple forms of insomnia. I now know I’m missing some …
Daniel Schmachtenberger: [inaudible 01:23:10].
Dan Pardi: Yup, REM sleep [crosstalk 01:23:12]. Yup so those all have their own unique components. Perhaps we should focus on voluntary sleep curtailment or the things that anybody whether you have a sleep disorder or not can either benefit from or have impair a normal state or even one that is more vulnerable because there’s already a sleep condition.
The things that it’s often called sleep hygiene if you think what are the things that are going to get you good sleep. You have to think of your sleeping environment and your sleeping behaviors. And so for environment, you want your room dark, cool, calm and relaxing. The ability for your body to control its own temperature is really important for sleep initiations, sleep depth and sleep consistency or consolidation so reducing something called wake time after sleep onset or WASO so not having a lot of fragmented sleep.
For that, people that have different temperatures that they feel comfortable. Some people are hot, some people are cold sleepers. Within a narrow range, the body does a pretty good job regulating by sticking a foot out of the covers so we tend to like or a hand or your head, they call them radiator parts, these are parts of the body that will have more efficient exchange of body temperature. You see a very specific process that takes place during sleep initiation where our body temperature is controlled into two different department, compartments so here’s your periphery and your core and so you can be freezing on the outside and your core is perfectly protected.
During sleep initiation, you actually have a vasodilation of your periphery. That allows for your core body temperature to release some of its heat and that rapid drop in core body temperature will initiate sleep. That can be really hard to do if you’re sleeping in a room that is too hot. Your body can’t … One big reason that is addressable but common is for people that don’t have the right temperature in the room, it’s just too warm, hard time going to sleep and their sleep stays lighter so that’s one of the first things to address.
Daniel Schmachtenberger: Now not everyone who’s listening is going to want to do this but there’s a sleep tech called Chili Mat which is actually a refrigerated bed topper so just to share a little bit why that is actually possibly meaningful for people.
Dan Pardi: I love my ChiliPad. I do not have any relationship with a company or any of the companies that we might talk about. It’s a really wonderful device. It is very thin mat that rests on top of your mattress. It has silicon tubes that run through the mattress and a tube at the end of the mattress or the topper that goes down into a box and that box has water in it and a fan.
You can actually control the temperature that is running through those silicon tubes very well so you can make it as cold as 53° and I think it’s warm is like 90 something and so if you are somebody who tends to be very, very cold at night, you can warm up the bed and if you’re somebody that tends to be very hot like I needed to be cold then you can turn it down.
Often times too, people sleeping in the same bed have completely opposite needs and so the ChiliPad has for a king bed they have one where you can have you can basically control the temperature on both sides [inaudible 01:26:51]. I’ve played around with it so I used to think oh I really want it to be super, super cold and that has to do with some of the hunter gatherer literature that I was looking into and thinking that perhaps temperature fluctuation of the course is another important variable. So in great situations, we can set the temperature a certain degree, 65° let’s say and it just stays there but if you think about a hunter gatherer community living outside, the temperature actually changes and decreases over the course of the night and then begins to rise.
Could that actually independently have an influence? One thing that I’ve done is I use my ChiliPad. I plug it into a Wemo switch which is a Wi-Fi switch and because it’s a Wi-Fi switch, it’s a part of my smart home technology so that means that I can configure it to actually turn on or off at a certain time. So when I am sleeping then I have my ChiliPad pretty cold but I have it turned off at 4:00 in the morning because what I found is that when I started to sleep with the ChiliPad, I’d sleep great and really deeply in the beginning of the night but then I wake up a little cold at 4:00 in the morning. And so now this turns off in the middle of the night and then it warms up and I continue to sleep soundly and uninterrupted until I actually naturally wake up so that’s one thing that I do. For people who need it, it’s absolute lifesaver.
Daniel Schmachtenberger: Ao factoring that falling asleep has to do with a pretty sharp drop in core body temperature, there's some other things that people can do before going to bed, they can help increase body temperature drop and help them fall asleep better.
Dan Pardi: Yeah so taking a hot shower, a hot tub, a sauna, I had on my own podcast Gary [inaudible 01:28:39] and it’s all about sauna and how just kind of the summary there. In 2000 and over 20 years, men who sauna 4 to 7 times a week had a 65% reduction in all cause mortality, 65% reduction in Alzheimer’s disease and other forms of dementia and also Myocardial infarction, really impressive results.
The magnitude to the degree of people that are exercising regularly compared to those who aren’t and probably some overlapped mechanisms. One part of our conversation we talked about when do people typically sauna in Finland because it’s extraordinarily common as a part of that culture. Most people, it’s variable, most people will do that right before bed and that you could also imagine that some of the benefits that are seen in that study might be from that depth of sleep that saunaing late at night, a lot of heat is going to cause your blood to travel to your periphery.
That’s part of the going down process. You step out of a hot sauna, you’ve got all the blood at your periphery and then you got more rapid exchange and loss of core body temperature. That’s why if you’ve ever gotten out of a hot tub late at night and then all of a sudden you just sleep like a rock, that’s the mechanism at play. It can help again initiate sleep and deep in it. That’s a great thing to do. You don’t need a sauna, you can also just use a hot shower.
Daniel Schmachtenberger: You’re talking about sleeping environment and making sure the sleeping environment is cool enough. The right temperature in general, cool enough is one thing. People being able to do a hot bath or a hot shower or sauna, if they are doing a hot bath there’s lots of other fun things, Epson salt, lavender oil that they can get into but what else in their sleeping environment?
Dan Pardi: Yeah, that's some pharmacological intervention with teas and essential oils. Maybe that’s part of a more advanced topic for next time but yes absolutely. So then a nut mask, earplugs, things that will, we all have different arousal thresholds so things that are going to alert us and wake us up out of sleep. There are people that can sleep through, they could live right next to a train and the train could go by and they’ll sleep right through it. The brain has the ability to filter out, the first couple of nights that the person moves into that apartment, they wake up because it’s a loud noise.
Eventually, the brain learns that that’s not a signal that should alert or that should make them fearful and yet at the same time a crying baby that’s less decibels in another room, the brain can still do some filtering and understand what’s important and what’s not. Yet still some people have that sort of arousal threshold where rolling over small little noises can disturb them. I’m one of those people so I’ve been sleeping with earplugs for 20 years in an eye mask.
There’s probably some placebo effect as well so I put it on, it’s just time for bed so there’s a conditioned response as well of relaxation but that’s an important one. One thing I’ll mention is with a lot of these things, everybody should go through a process where they try to figure out what’s right for them in their current environment, at this time of life and do some experimentation.
Good sleep cannot be judged from one night of sleep. Let’s say you slept more one night and you feel groggy the next day, that doesn’t mean you typically don’t need a lot of sleep. You got to play with it, yeah, do some self-experimentation. So that’s I would say mostly for the environment, cool, dark, comfortable good sheets and mattress. Mattress is a whole other subject. You don’t want essentially to sink into the mattress with memory foam. You want to be able to control body temperature really well. After that, there are various variability in terms of what individuals need. Then there’s the behaviors so getting enough physical activity-
Daniel Schmachtenberger: While we’re on sleeping environment I want to double-click on a few of those then we’ll get into the behaviors and then we’d be at a good wrap point. So you mentioned the importance of people experimenting. Obviously this is their safe environment and behaviors but there’s a bunch of sleep monitoring devices that can be part of someone’s sleep environment. Historically, many of the early ones had low enough accuracy that it's hard to make meaningful sense of them.
Obviously, people are not most sleep monitors available are not EEG based so you’re extrapolating. What can you say about sleep monitors as a way for people to experiment in addition to their own subjective experience and just paying attention to how much they slept and how they felt and which ones if any you have found accurate enough to be worthwhile.
Dan Pardi: Yeah, I was thinking about talking about this next time as we’re getting more sophisticated but it’s a great time to talk about it because yeah, if you're sdoing some self-experimentation to try to understand your sleep, it’s really one, the thing that ultimately matters as much as anything else is subjective sleep experience or sleep satisfaction. You wake up and you feel really restored. And so a lot of what I’ve been working on and thinking about is a concept called the restorative sleeper, somebody who wakes refreshed everyday and feels alert all day everyday. That’s the goal.
Whatever it takes to get there as long as there’s not some pathological process that’s happening in the background that is sort of in surprise because your sleep is inadequate but sleep monitoring through quantified self or self-tracking has become a lot more popular. Earlier versions before, these sort of monitors was diary, sleep diary, which has been used in research for a long time. And in those diaries you tend to just look at what time you go to bed, what time did you wake up and then you could understand at least the sleep period length so sleep period is the time that you try to go to sleep and then you actually wake up. Your sleep efficiency is actually happening somewhere in there.
Then there’s the timing. Again so remember the timing is also really important too. Do you have great variability when you actually go to bed? That’s another independent factor that matters. So the earlier versions of the quantified self devices, these instruments that you can wear on your body that can detect some aspect tended to have ActiGraph which are things that detect movement. In fact the earliest version was more sophisticated called Zio and it went out of business but that was a headband that had a unipolar lead that was designed to try to be as close as possible to PSG although it was never validated and therefore it was probably too onerous for a consumer to use. It was not validated so the sleep text just didn’t really they were waiting for that information.
Next was the Fitbit which is most common. This is worn on the body. Earliest version was a little clip that you put on your jammies. Next was wrist worn typically. That again was measuring movement and also sleep timing and there was a real value to that because then you could get people, you could help them set goals how long do you want to be in bed and then also help to focus on sleep timing. The newest generations, and there’s also things that lay on top of the mattress and they will detect things like movement and now even heart rate.
As we’re getting into more sophisticated devices like the ŌURA ring. This is a ring that is made out of a group from Finland. They are ex-Polar employees. You remember Polar made the heartrate draft that measured heartrate. This is probably the most sophisticated consumer heartrate sleep tracking device on the market at least that’s been shown in some studies that have been conducted looking at the top sleep trackers that are available.
Why is it good? Well where it’s detecting it’s detecting movement for one and it can also look at your pulse rate and also pulse rate variability which is an indication of physiological stress. So now what we’re seeing is the ability for these devices to collect multiple different physiologically relevant parameters that you can then triangulate to then pinpoint what is out there, what stage of sleep are you actually in. That’s what a polysomnography does. It is a multiple measures of sleep so looking at heart rate, breathing rate, EEG activity and while polysomnography, these 27 different leads that are on the body that make it impossible to sleep well they can detect, they are better at detecting things like sleep apnea and narcolepsy. This is much better for actually detecting physiologically relevant sleep because it is so much less intrusive so it’s less accurate but more relevant to what we’re really trying to measure because it’s not trying to assess or diagnose sleep pathology, it’s just trying to then give you good insight of what your sleep is actually like.
That can depending on the levels of sophistication of what it gives back, that can do a variety of things. There are behavioral elements and then there are things that can ultimately say, “Gosh I get a lot more slow wave sleep when I sauna at night,” or if, “I had no physical activity this week and I didn’t walk certain amount of steps and my slow-wave sleep was lighter.”
The future of this is where algorithms are running in the background that are actually collecting data over time periods and then statistically telling you what matters. That’s what where this will go because you can also be over responsive to I had a teaspoon of almond butter and I got more slow-wave sleep and therefore I think that’s really important. That can happen. It could be true or it could be false so you can have those sort of those false positives but this is where things are going in terms of physiology or behavior modifying devices and it’s very, very powerful because like I said you could then figure out gosh when I adjust my room temperature to this degree, I’m actually sleeping more deeply. That’s pretty cool. We need this countervailing technologies to help us in today’s world. That’s why I’m so excited about them.
Daniel Schmachtenberger: I want to do a more thorough review on OURA but we've talked about it a little bit. From what I’ve seen on I’m really impressed with the hardware. The other one that I really have liked for at home sleep monitors that are not invasive is the Beddit system. Do you have much thought on that?
Dan Pardi: I have not used it maybe you could tell I know that it lays on the bed and so it detects …
Daniel Schmachtenberger: Piezoelectric is very subtle pressure sensing but supposedly the pressure sensing is enough that it’s not only looking at movement and breath but even heart rate variability, pulse and heart rate variability and then being able to put all those various axes of information together. I think I’m actually about to reput the Beddit on my bed and grab the OURA and compare them so then I’ll report back on that when we talk next.
Dan Pardi: I do that with my Fitbit and my OURA [inaudible 01:39:35] which one’s right.
Daniel Schmachtenberger: You got to put them both on and then actually go to a sleep lab and get the EEG done. Now OURA has been compared in the sleep lab.
Dan Pardi: It has yes and so they have, I mean the benefit to them is people haven’t been doing this sort of tracking very long. It’s new and Polar has been around for 20 something years so they had these engineers and algorithm developers that have been thinking about this stuff for a long time. That’s a really cool attribute to them is experience, rare experience and the position of where they are collecting information on the finger actually happens to be very good because a watch will move around more, your [inaudible 01:40:20] on the front side of the wrist so underneath my Fitbit, I’ve got that’s where a lot of the signals detected for a heartrate.
This is more venous. That’s not a great place to actually detect heartrate and heart rate variability, you can but underneath the finger, you have more arteries and then veins, it’s more stable. There’s less movement, you have a tighter connection. This has these ring samples at 250 times a second that wears a Fitbit watch. This is a blaze that samples at 12 times a second and with that degree of monitoring, you actually can get a better signal overall and so that’s why I think you can have their confidence to know what you’re getting back and yet still big data is another component.
Fitbit has the advantage of having millions of people use their devices and then being able to sort of retrofit and curve fit their information that the weak signal that they get back into actually pretty relevant and accurate information because the big data component so that means looking at millions of people and understanding what happens based off of massive amounts of data. That's sort of an advantage that they have currently.
Daniel Schmachtenberger: So people learn more about how to actually kind of study and optimize their sleep better creating a sleep diary quantified self devices, what things to pay attention for. Is there a good research to recommend?
Dan Pardi: Let’s see, yeah, I mean you’re right, there’s stuff all over the place. It’s hard to consolidate because some things are common, sleep hygiene, things that everybody should do. I do a lot of speaking on that. The restorative sleeper model that I put together is aimed at trying to give people a one-stop place to hit most really important factors so what are the things during the day that actually help good sleep at night, what are the things that you should think about for your environment and what about light so smart light rhythms in the evening and night.
Most people that do that and actually stick with it are going to do well. You’ve got a conducive environment, you’ve got good behaviors during the day, good environmental exposures. You're going to be in much better shape than most folks. Then it’s fine tuning after that. It kind of depends on what that individual’s need is. Their sleep could be disrupted because there’s so many things that can disrupt healthy physiology like diet like healthy gut functioning and all of those do have an impact on our physiology and the functions that, those tissues and organs do.
Daniel Schmachtenberger: Our next session, we'll be diving into those things.
Dan Pardi: Yeah, cool.
Daniel Schmachtenberger: Okay so in just kind of wanting to wrap up here, sleep environment so you mentioned earplugs. I can’t sleep with earplugs so I like white noise generatorsw and I happen to like addressing air-quality so I just run a high-quality air filter in the room that does both functions and specifically high-quality air filter meaning depending upon what the environment needs. For me that’s a HEPA filter and negative ion generation which there’s some good research affecting sleep having increased negative ions in that sleeping environment but without ozone so I think that’s a cool tool. Then I think my single favorite tool is blackout curtains.
Dan Pardi: Yes, yes. They’re amazing and they are better than eye mask. I have a good eye mask that actually blocks the light from coming in under the mask.
Daniel Schmachtenberger: What’s it called?
Dan Pardi: I got it on Amazon and I don’t know the name.
Daniel Schmachtenberger: All good. I haven’t found any that are perfect but found some that are pretty good.
Dan Pardi: This one is way better. I've bought this one multiple times because it's just a much better [inaudible 01:44:22]. With a lot of the stuff, I mean there’s other sort of experimental technologies like stuff that you mentioned that I did not that I don’t know a ton about but could legitimately have a meaningful contribution to getting good deep sleep.
Daniel Schmachtenberger: Now, on the bed topic this is actually kind of a deep topic when you start to get in to the actual chemistry of a mattress and a mattress that is treated with flame retardants that happen to be kind of endocrine disruptors and neurotoxins themselves that you’re breathing in and has some other kind of VOCs in it the way that most mattresses become filled with mites or susceptible to mold so there’s like there’s a lot that goes on as well as orthopedics of a mattress as well as the temperature regulation of a mattress.
There’s of course a lot of particularly good orthopedic mattresses and there’s a lot of particularly good organic mattresses and unfortunately those two are not the same thing. Some of the good organic ones suck orthopedically and vice versa and they have a few that do a really good job of both maybe next time we'll actually dive into that more. I went ahead and I did a deep dive into the mattresses at one point. I actually have the SAMINA mattress system and it made a pretty significant difference.
Dan Pardi: Yeah. We can talk about it because you’re going to know more than I do about some aspects of mattress and then I’ve done a little bit of an analysis on some of the more orthopedic elements so that will be fun [inaudible 01:45:53].
Daniel Schmachtenberger: All right fun and then other than sleep environments so we want it to be quiet, we want it to be dark, we want it to not have associated stressor. When they’re in the room, they are not associating mind activity whatever stressful thing so being attentive to their sleep environment’s important. Sometimes dogs in bed, kids in bed, their partner in bed can be a major factor to pay attention to. Other than the sleep environment things and really kind of making a sleep sanctuary, what are the main behavioral sleep hygiene things and I think probably eating before bed versus not, blood sugar during the night, inflammatory food topics. I think that would be one good one to address.
Dan Pardi: So having a big meal before bed, one thing I noticed in speaking with the CEO [inaudible 01:46:47] president of OURA ring, we both were commenting that I was in a situation where I had to skip dinner because I was fasting and I got so much deep sleep like way more than I had so just skipped it all together. I definitely try to eat early for the most part but socially, that can be really challenging.
Meal timing is not completely dependent on you, the individual, half the time. It’s when the family is ready, when the kids are home from school, when the meeting is just, that’s how life tends to be so that can be tough but it matters. Food itself matters as well so [inaudible 01:47:31] did a study that showed that it wasn’t necessarily the food that was taken right before bed but the food that was eaten that day particularly high-fiber actually contributed to deeper slow-wave sleep.
Saturated fat in her study was the opposite. It led to more sleep fragmentation and less slow-wave sleep so food matters, then timing of food, the size of the meal if you’re thinking of also about behaviors too, if you want to think about it as sleep behaviors if you will getting into bed and then using your devices, light emitting devices, you can certainly change tone and intensity of the light that is being emitted.
For some using your phone before bed is stressful, some it's stressful eating. You feel like okay I’m on top of everything, I can relax so it really depends on the individual. What I would say is that the phones have messed up my sleep in the past because I would wake up let’s say early in the morning and instead of just letting myself go back to bed, I would start to check email start to surf and instead of going back, falling back into sleep I now just lost an hour and half of sleep because of my phone and it’s right next to my bed. It’s so easy to grab.
You have to think about your relationship with it. What you want to do if you have sort of a clear goal. I’m just not going to look at my phone until X time. You have to think about what’s going to work in your world. I could put out like hey here are some clear guidelines and be sort of authoritative about that but the fact of the matter is we all have to sort of figure out what works for ourselves but understand certain principles that are [inaudible 01:49:18].
Daniel Schmachtenberger: So some of those guidelines I think just at least so people know you mentioned the light coming from the computer or the phone so downloading the flux app is a possibility. This takes out the blue spectrum which is going to be most stimulating to cortisol. I think that’s a good thing for many people. I happen to be irritated by orange light so the [inaudible 01:49:42] bugs the shit out of me but I think it’s good for a lot of people.
Some people wear blue blocking glasses and so wearing some kind blue blocking glasses is another possibility. Obviously decreasing the brightness of their screen and the brightness of indoor lighting and the blueness of indoor lighting before bed are all big positive steps one can take I mean just a wind down routine where after the last time someone is on the screen, there is some process that prepares the body and mind for bed probably makes as much of a difference for sleep as anything else that I know of.
Dan Pardi: Particularly for people for some people, yes absolutely. If you tend to ruminate or have any anxiety or just a racing mind, meditation, a wind down routine, it’s often good-
Daniel Schmachtenberger: Hot shower or sauna, we talked about.
Dan Pardi: Yeah, thinking about ways in which you’re transitioning into sleep, for me I actually like to take notes about [inaudible 01:50:50] tomorrow. I feel like I sort of purge any ideas that are in my mind. I like that writing time even if it’s just work related and then I organize my day in terms of what I want to address first with priority. It’s very relaxing.
Daniel Schmachtenberger: That’s my last thing to do every night too. Because then the mind stops running because it actually captured it all. That’s kind of David Allen’s getting things done when you captured it all, mind gets quiet.
Dan Pardi: That’s 100% true in my world.
Daniel Schmachtenberger: If what you’re wrestling with in your mind is kind of emotional content then just journaling, super valuable, if what you’re wrestling within your mind is a lot of to-dos and then just actually doing a brain dump of that.
Dan Pardi: Another technique that I’ve used if I’m wrestling with some sort of emotional content is to listen to a podcast which is not typically what you’d want to do but I will put on something that captivates my attention that is different than the own internal dialogue that is keeping me up whether the valance of that emotional content is negative or positive or whatever, it’s just activating. If I realize that I'm in that state that putting on the podcast, listening to somebody else talk and getting to their stream of thought can help me, my mind relax and I don’t use that commonly but I do use it pretty reliably when I find myself in that situation.
Daniel Schmachtenberger: I actually love reading before bed but not on an iPad or Kindle. I actually like paper book not so dimlit that it's bothersome to the eyes but lowest kind of lighting that is fine for the eyes and then of course not reading something where it’s stimulating and you want to go take notes about what you’re going to do with that knowledge so reading philosophy, reading spirituality, anything that is generally going to be positive in its orientation but also maybe on the boring enough side that it actually, you fall asleep as you're reading it is something I enjoy.
Dan Pardi: Oh Daniel I’ve tried this I guess indicative I’ll read a half a page and I'm out. Reading I should do more but I don’t, I get frustrated because I can never make it past a page or two. It’s a great way for me to go to sleep but it’s not great for covering books.
Daniel Schmachtenberger: No coming back to the other things you were talking about the food before bed I just want to mention select Ayurvedic medicine is one of the classic things not eating several hours before bedtime and so the digestive system actually gets to rest while the body is resting. The digestive system is not active and awake when the body is trying to rest during that time.
On the other side, you’ve got the concern around going low blood sugar at night and then cortisol spikes when you go low blood sugar to release glucagon and so there are a whole bunch of people that are dealing with blood sugar things that actually say eat a handful of nuts or eat some MCT oil or something that is not particularly heavy before bed but where you're going to have some slow release fuel that will maintain the blood sugar throughout the night. What are your thoughts on that? I mean obviously test and individualize but general ideas.
Dan Pardi: Yeah generally speaking, the control of blood glucose goes through a very, very tightly regulated and it is a perfect example of the dance that the brain does and the body does in order to regulate our physiology. If you think about it, if you ate dinner, you have some blood glucose circulating in your bloodstream, you go to bed and then what does the brain do, it actually releases growth hormones because you get into the deeper stages of sleep.
Actually excuse me before I can get there, you should be under low light, dim light. Insulin is suppressed by melatonin so melatonin acts directly on pancreatic beta cells and it suppresses the release of melatonin or excuse me, of insulin so typically if you had a certain amount of circulating glucose then that would be cleared out your bloodstream by the insulin. Instead melatonin keeps it active which is actually one of the problems.
If you have a very big meal then it's dark it’s not getting cleared so that is both sort of a positive thing and then potentially a downside to eating late in a high glucose meal then blood sugar is continually regulated by the release of growth hormone which will also keep it active, keep the blood glucose adequate. As the night advances then you’re still of course suppressing insulin by the continual melatonin release but you also have a change where now it is being regulated by some circadian factors.
By the slow rise of cortisol. Cortisol is rising as a way to actually keep glucose in the bloodstream for a bit longer. That is that dance that takes place under healthy normal physiology. A big problem that a lot of people have is probably the circadian misalignment. It’s so incredibly common in our world so you measure cortisol and actually cortisol is causing a problem or is the fact that your rhythms are off the Symphony that is playing is playing out of rhythm.
Now I have all been dropped if you will at certain points. One of the very first things that people should do that are dealing with a variety of issues is just get your circadian system under control as best you can. A lot of flight during the day, dim light at night. Then I wear glasses but I do it or keep everything very, very dim. I have a setting on my phone actually I’ll show you. So I pushed three times, it goes really, really red. It’s called color shifts. It’s basically like wearing the blue blockers. It’s actually much more pleasant if you’re just reading. If you're doing anything graphical, the orange really stinks but anyway, do that and that’s going to help with the blood sugar regulation.
If you have a problem then you got to kind of figure that out. The first place to start is get your circadian rhythm in line and then after that is inline, give it about three weeks, I'm doing everything perfectly then see if it persists and go from there, see what the issues are.
Daniel Schmachtenberger: I think this is a good wrapping place. We actually discussed quite a lot this time to foreshadow next time talking about sleeping all at once versus having sleep broken in a couple chunks or multiple different chunks talking about how much of people’s circadian rhythm is kind of innate versus changeable and people who are oriented towards later night or early morning how much someone’s sleep need is fixed versus changeable genetics that are involved in how we can assess those genes and understand them and then getting into some of the neuro tech more and some of the supplements that can affect sleep. I think this was a good foundation to understanding why sleep is important, some of the mechanisms that we know that mediate it and some of the entry foundations to starting to optimize it so it was fun.
Dan Pardi: Yeah it was. Thank you.
Daniel Schmachtenberger: Thangs for being here and thanks for your work in the field. Like you were just mentioning with insulin, the effect on diabetes we just think about, you think about weight, you think about diabetes, you think about Alzheimer’s, cancer, so many things that are sleep affected, obviously food, obviously exercise, obviously mindset are all critical. If we were to get sleep better optimized given that we built a world that didn’t factor it in a way that we did lighting and whatever we just didn’t factor noise. Come back to us, we’re learning more. It will be really profound for not only physiology and disease, economics associated but for psychology and that also means human relationships and that also means overall quality of all kind of human behavior, macro skills so important.
Dan Pardi: Yes, well yeah think you. It’s for me it continually provides incredible challenges to really understand things well and I look forward to that. There’s no way that I’ll ever understand everything just in this one sliver of health and yet it’s that kind of fun in a way to help provide an endless puzzle and yet at the same time, you don’t have to wait a lifetime to understand some of the major players that can affect your life. You can get these things that are really beyond basics that are pretty sophisticated and yet part of the scientific dialogue is to always challenge every element of that. So that’s kind of fun to have a foot in both worlds translating what we know at least currently as best we can into interventions that can help make people better, live well, be happy.
Daniel Schmachtenberger: I did want to say as we’re closing, you have a new project that you’ve been working on for a while some years that is launching depending upon when this podcast launches, it will probably already be launched. It's human OS, human operating system where you got kind of like most essential vital content on many of these topics, sleep, diet, exercise and then also behavioral support go right into it so that’s exciting. I’m really looking forward to seeing that platform how can people go and find out more about it?
Dan Pardi: Yeah I’m tremendously excited about it as well. My life’s work, absolutely. HumanOS.me. If you go there now, it might direct you to a site called dance plan where you can check out the blog and do a lot of podcasting and blogging there but depending on when this is released it might just go you might be one of the first people to check out the new systems [inaudible 02:00:46] working on in some form starting with a behavior model that I developed years ago in academia to now operationalizing that into a tool that's meant to help people in extraordinarily sophisticated way to maintain a pattern of living that's going to yield all the results people want is close but it’s kind of the … Without going into detail about it, the idea here is that we sometimes look at technology as though it’s going to intervene and do stuff for us.
The whole point of this is that it’s best viewed, technology is when it helps us do the right things so we’re still at the center of how we live and the choices we make and this is meant to sort of empower you to become an expert at your own health and I call it a personal health mastery platform and it’s not something that you can come and in one week, you know everything. It’s more about this is something that accompanies you along your journey and it will for me as well. I learned some new stuff through it every day but that’s the purpose and I’m excited to release it.
Daniel Schmachtenberger: Awesome. We’re excited to be able to share more the content that you're generating on there.
Dan Pardi: Thank you.
Daniel Schmachtenberger: All right thanks Dan. Thanks everybody. This is fun.
Dan Pardi: Yeah. Take care.