The Role of the Downstate for Sleep, Restoration and Longevity with Dr. Sara Mednick

Sleep – we spend a third of our lives doing it, we know it is a powerful longevity tool, yet we continue to skimp on it. I know from personal experience – improving my sleep after struggling for years was a total game-changer. And in this episode of New Frontiers, I’m joined by Dr. Sara Mednick, world-renowned sleep scientist, professor of psychology at the University of California, and director of the Sleep and Cognition Lab to discuss her exciting research findings and new lexicon for understanding stress.

Together we explore why aligning sleep with the nervous system’s downstate is more important than sleep duration for optimal restoration and longevity – AND how you can use heart-rate variability to measure restore function. We also talk about green exercise, harnessing the power of dreams, setting health boundaries, the connection between meal timing and melatonin, and WOW — so much more. This one is a gem-packed session for sure, so get ready to take some notes and get inspired! And if you don’t mind, please consider leaving a review on iTunes or wherever you listen to New Frontiers! Every thumbs-up helps us reach more people! Thank you! ~DrKF

The Role of the Downstate for Sleep, Restoration and Longevity with Dr. Sara Mednick

Is sleep our only way to restore and recharge? In this episode of New Frontiers, we are joined by world-renowned sleep scientist, professor, and author Dr. Sara Mednick to understand why restoration is incredibly important and what we can do, other than sleep, to help our bodies feel restored and slow down aging. Dr. Mednick talks to us about the importance of downstates of the autonomic nervous system, aligning sleep with our natural rhythms, getting to bed early & timing our meals, and using heart rate variability as a restoration measure. Her new book Power of the Downstate redefines the way we talk about stress and restoration and inspires us to take a more holistic approach to sleep and restoration.

In this episode of New Frontiers, learn about:

Dr. Kara Fitzgerald: Hi, everybody. Welcome to New Frontiers in Functional Medicine, where we are interviewing the best minds in functional medicine. Of course, today is no exception, I am talking with Dr. Sara Mednick. Let me give you her background and you’ll see why I’m really happy to be chatting with her today. She’s a professor of psychology at University of California, Irvine, where she directs the Sleep and Cognition Lab. Her first book, Take a Nap! Change Your Life, put forth the scientific basis for napping to improve productivity, cognition, mood, and health.

A world-renowned scientist, Dr. Mednick’s lab investigates the mind and body mechanisms that support performance improvement. Her work has been continuously federally funded with grants from NIH, from the National Science Foundation and the Department of Defense. She’s been interviewed everywhere, by everyone, including the New York Times and the Los Angeles Times and the BBC. She’s been on Good Morning America and many other shows. She resides in San Diego with her wife in the Hudson Valley. Sara, welcome, welcome to New Frontiers.

Dr. Sara Mednick: Thank you so much. It’s wonderful to be here.

Dr. Kara Fitzgerald: It’s just so cool to… Her newest book coming out, Power of the Downstate, which is what we’re going to be talking about is published by Hachette, and she and I met through a Hachette function. Sara, I just thought you were the coolest immediately from that little press junket thing that we did.

Dr. Sara Mednick: It’s because I kept just texting you while other people were talking and we just had our own little side thing going.

Dr. Kara Fitzgerald: It was really interesting. You’re doing such cool work at your lab at UC. I want to learn about it. I want to learn about your new book. I want to share it with the world and just get your take on Downstate. What is it? You’re creating a new lexicon for understanding stress. You’re talking about downstates, recovery plus, rev-restore. Just talk about this new understanding of stress and this new lexicon and what you’re doing.

Dr. Sara Mednick: Sure. Thank you so much, first of all, for having me on. As you said, I am a sleep scientist by trade and in my lab I’ve been studying how we restore during sleep. Through that process, I got to really see that sleep is not the only way we restore, and also that restoration is incredibly important, and if we don’t focus on restoration, this is what leads us to grow old faster and to have chronic diseases.

One of the ways that I realized that, that was happening is by looking, not just in the mind, but also with the brain and using EEG, electroencephalography, but also looking at what’s happening in the body by using ECG or electrocardiogram in order to look at how the autonomic nervous system was functioning. What I saw across many different types of research studies was that our brains and our bodies are rhythmic.

What that means is that we have… What does rhythms give us? Rhythm gives us two different states. One state is what I call the upstate. That is the time that we have most of our energy. It is where our bodies are filled with glucose and glycogen and our insulin levels are at their height, our metabolism is at its height, our strength is at its height.

Then we also have, have the other half of this rhythm, which is what I call the downstate. That’s the time where we need to replenish all of these resources. Every animal, every living thing, every plant follows this rhythm and the more you get in sync with your own internal rhythm, the more you are able to resonate with that rhythm and have more energy when you’re supposed to have energy and be able to replenish more when you’re supposed to be in your replenishing state.

That’s the upstates and the downstates. Then, I also wanted to reassess how do we think about these different systems that we have? We know that there’s wake and sleep. We also know that wake and sleep can be two parts of the same rhythm, the circadian rhythm, but then we also have the autonomic nervous system with what we call the sympathetic nervous system, the fight or flight and the parasympathetic or the rest and digest.

I wanted to also reinitiate those terms into words that we could use, terms that we understood. I redefined the sympathetic nervous system as rev, because what it does is it makes us rev. We’re revving when we’re in that fight or flight response. Then when we hit the parasympathetic system, the rest and digest, I call that restore. They are also two sides of the same rhythm, two different sides of the same rhythm with the rev as the upstate and the restore as the downstate. Hopefully, these are more intuitive ways of understanding how we can access these rhythms and understand these rhythms and how they work together.

Dr. Kara Fitzgerald: Yeah. I love it. It does feel so much more complete than to sleep or not to sleep. It feels much more holistic, in the experience of a day or a week or a month, just the rise and fall of different states.

Dr. Sara Mednick: That both sides are essential. If you think about an ocean wave crashing on the beach, the crash doesn’t happen without the drawing in, and the preparatory part of the wave, and that’s the downstate, that time where the ocean draws back into itself, builds its own motion, its own power, its own strength. Then once it’s built up enough, then it crashes out and that’s the upstate. You don’t have a system that’s all upstate. You always have an equal and opposite downstate that has to happen just before the next upstate.

Dr. Kara Fitzgerald: Well, let me ask you, in your work, how did you study this? You used ECGs and EEGs? I’m just curious how you set this up, where you perceived it? It’s just really elegant and interesting to me.

Dr. Sara Mednick: Thanks. I started just like where everyone else is, is just using EEG and looking at brain activity and neurons and groups of neurons as they show themselves on the EEG. But then I also had that thought in the back of my head that we’re not just brains, we have these bodies. The autonomic nervous system is so often discounted by neuroscientists because it’s thought of as just being a system that’s for basic water and power functions and temperature control, but not really playing a role in any of these things that the lofty brain is doing.

Then there was a group of interesting scientists I met in Australia who were doing work on HIV and the cardiac rhythm. I thought, well, that’s really interesting because I also knew that the restored response, that parasympathetic response was specifically high during sleep, but nobody was looking at how the autonomic activity during sleep was contributing to any of these cognitive findings that we kept finding in the lab. Everyone was saying, “It’s the brain.” I’m like, “Well, let’s just take a look at that question.”

We started measuring ECG along with the EEG and that’s where suddenly we started finding all these amazing results where it turned out that I could account for more of the cognitive benefits from sleep, by looking at what the heart was doing and thereby measuring autonomic nervous system activity, then by looking at the brain itself.

Dr. Kara Fitzgerald: Can you give me an example?

Dr. Sara Mednick: Yeah. Across the day, your autonomic system switches in dominance. During the day, it’s mostly sympathetic, what I call rev. You’re revving, because you’re in that state of going and doing and being. That requires a lot of energy and resources. When you go to sleep, one of the most important aspects of sleep is that you have this huge bump in restore function. You have this huge burst in parasympathetic activity. That’s true for young people, and you see really powerful increases or switch in dominance from sympathetic to parasympathetic or from rev to restore in sleep, and specifically with slow wave sleep, that deepest restorative part of sleep.

Then we started examining the magnitude of the restore function during sleep and all of the cognitive benefits we were showing and finding that actually the restore function was accounting for more of the memory improvements than the slow oscillations themselves or the deep sleep themselves that was just measured in the EEG.

Then when I started looking in older adults, people 60 and up, brought them in the lab, looked at their sleep and they really showed very little parasympathetic or restore function during sleep. They also showed really no benefit of sleep for any of these cognitive benefits that we show in younger adults. It started really putting together this idea that, first, if somebody who studies sleep, you understand that we’re rhythmic animals. If you study circadian rhythms, you know that every aspect, every cell in our body is rhythmic.

But then when you start seeing how these rhythms interact, that you have this rhythm across the day, that every system in our body really obeys. If you can align yourself with those rhythms, like your metabolic system, using your muscles with exercise, your brain thinking, meditating, any of these things that really align with these day-night rhythms, you have really strong functions and you’re much more powerful and you think better and your body’s more fit.

Then as we get older, it looks like we lose these rhythms, or we lose touch with these rhythms. It seemed really clear that, that was part and parcel of the reason why older adults lose functioning is that they stop really having this strong parasympathetic response during sleep, they stop exercising as much, they avoid light, and get that strong circadian burst in the morning that tells them and regulates their rhythms. Those are all from that lab.

Dr. Kara Fitzgerald: It’s fascinating.

Dr. Sara Mednick: Yeah.

Dr. Kara Fitzgerald: We were talking earlier about my daughter, Isabella, who figures into a lot of my conversations. I’m just picturing her before bed. She’s bouncing around like a bunny. We don’t do a whole lot of quiet… We do turn the volume down on life a little and she takes a bath and that kind of thing, but she’s still bouncing around. She can’t help it.

Then she’s got a transition into sleep with a story and a little cuddling and she is out, just out. She’s moved right into restore, and she’s moved from being in a pretty sympathetic place, but her transitions are really marked and clear. Whereas what I hear you saying about, as we age and as we get middle aged and beyond, we’re not experiencing sharp demarcations. We’re not moving our bodies to getting a good sweat or engaged in rigorous intellectual activity or maybe deep community and connection, or the other nourishing experiences in life. Maybe our diet has become really compromised and-

Dr. Sara Mednick: And exposing ourselves to bright light early in the morning, and we have so much exposure to light at night now, which also really interferes with our ability to tap into our natural rhythms. Everything you’re saying is right. Your daughter’s a perfect example of that built in… If you look at kids, they have that built in rhythm and they don’t mess with it. They obey it and they just go straight into it, and it’s super, super powerful and strong.

We have that through our 20s, and then starts to change in our 30s, and really in our 40s as well. How those downstate systems break down in our 40s and 50s can predict our risk for dementia and Alzheimer’s in our 70s. There’s things that we need to think about as early as our 30s to stave off what happens in our 70s. I think that’s something that it’s hard to think about like, oh my God, whatever I’m doing tonight is going to have an effect 30 years from now.

Dr. Kara Fitzgerald: Yeah. Well, I think that’s really terrific. I am focused on longevity now these days with our publication, and certainly that’s a conversation that’s being had in the longevity spaces of why not eat right in your 30s? Why not consider some of these things? What happens? What’s that breakdown journey? Is it, “normal” or is it a phenomenon of the world that we live in?

Dr. Sara Mednick: I think it’s actually a phenomenon of the world that we live in. I think that to some extent there is a decrease in melatonin across age. That the rev-restore system has got to be in a balance and there’s got to be a control of how much sympathetic arousal we have by the parasympathetic system. Restore has got to come in and decrease rev at the right time, and over time, for older adults, it’s harder and harder to access that parasympathetic system.

I think that, in some cases it may be natural. There are studies that look at more primitive tribes without electricity, and without any of the modern ailments that pull us away from our natural rhythms. Even in those cases, you see that older adults do stay up more at night. They definitely have a weaker rhythm so that, when they’re “supposedly sleeping,” sometimes they’re awake.

There probably is some natural change that occurs. Maybe that was also evolutionarily helpful to have somebody up at night keeping the fire going. I doubt that all of this stuff is all just from toxic contemporary society, but I know that a lot of this stuff also doesn’t help. The amount of stress that we have now, just from social media, just from 24 hour news cycle, just from the social pressure that we have in terms of pushing ourselves and to not necessarily have a really good retirement plan and, be stressed by the amount of credit and the amount of money, everything costs.

I think that we are living, in a way more daily high levels of stress environment. It does make for a harder battle for our restore system to have to control all of this and to have to calm us down every night. I think we don’t have a practice, at least in America, for really emphasizing and prioritizing downstate activities. We don’t have a practice of taking breaks. We don’t have a practice of having really decent vacations, or of really supporting healthy behaviors from institutions that either hire us or educate us. There isn’t really a good emphasis on that in our society, and I think that really takes its toll in terms of the level of chronic stress that people have and the chronic illnesses that people have.

Dr. Kara Fitzgerald: Yeah, absolutely. This need to push, to just be in rev all the time. As I was talking to you earlier about my own journey and my book launch, being hard to say no, and being okay with turning things down and just, I need to focus on restore. I am going to move into restore mode really, really soon. But we need to do it, as you say, every day.

I wanted to just circle back to this idea, as we’re in rev or rev encompasses a lot of different things from working and thinking to physical activity and all of the various things that we’re doing, I think during our waking hours. It sounded a little bit like meditation… It reminded me of Zen. When exercising only exercise, use your muscles. When thinking, really think. Are we half-assed about these things as we get older, not fully being in them and perhaps it’s because we’re not fully recovered? Any thoughts on that? Does that make sense?

Dr. Sara Mednick: How many times have you talked to people who are having a work walk?

Dr. Kara Fitzgerald: Of course.

Dr. Sara Mednick: I was on the phone the other day with a guy who was obviously in a really busy New York City environment, and he was trying to have a work talk with me and say, “I’m doing this exercise stuff.” But he’s working and he’s in this crazy, very busy environment, and I couldn’t quite hear him. I thought, this is it, this is us multitasking, trying to have it all and trying to have it all at the same time. I don’t think that we can’t have it all. I really feel like I have it all.

I have this amazing wife, she lives across the country from me, so I don’t have it all at the same time. I have these amazing kids and I have to share them with their dad. So, I don’t have them all at the same time. I have this incredible job and it’s in Irvine and I live in San Diego. So, I don’t have that job all the time. But when I have it, I really want to have it and be part of it and be present with it. But what that means is that I can’t have it all at the same time or I wouldn’t do it all well.

That idea of continuing to push and try to have as much upstate stuff at the same time every day, all the time, it is going to lead us to disaster. We cannot keep pushing ourselves to try to maximize, constantly maximize all of our time to push as much into those minutes and hours of the day that we have.

Dr. Kara Fitzgerald: The changes that you saw on ECG and EEG have to do with this attempt to mush it all together and doing a lousy job at all of it and not restoring. Would you say that’s true?

Dr. Sara Mednick: Yeah, very much so. That as we get older, how we are naturally meant to behave, we ignore it. We start to try to control it, and we start to ignore those signals that say, you know what, I really should be going to bed at 10:00 PM or 9:00 PM every night, because I function best that way. I really should probably not have alcohol every single night, because what’s that doing to my sleep? I probably really shouldn’t try to say yes to every opportunity that comes to me in one week, because I don’t actually have any time to go take a walk and do any exercise, and I’m just going to feel crappy, and not be at my best.

We start to get into the state of denying our own personal rhythms in effort to just do more. It is a losing game. It’s not a rational choice that we’re making.

Dr. Kara Fitzgerald: I hear how crisply, you define the pieces of your life, and it just strikes me that you really learned from your own science, and I love it. It’s inspiring to hear.

Dr. Sara Mednick: Well, it’s interesting, I think, as much as I write this book in order to just say what’s in my head and get it out there so people can hopefully benefit from it, it’s as much a constant daily struggle for me as well. Who isn’t watching the news right now at 10 o’clock at night or 11 o’clock at night? Who isn’t checking social media to see how many people are liking what I’ve said?

This is the way that we live now. There’s this idea of just personal health boundaries and the personal health boundaries have to be set by you in the same way that you would set relationship boundaries. You have to have your own relationship to yourself and know what works and what doesn’t. The more you get your boundaries crossed in relationships, the more toxic that relationship will be. Well, it’s the same thing with your health boundaries. If you’re not sticking with those boundaries, you’re not going to be the powerful person that you think you are, or that you want to be.

Dr. Kara Fitzgerald: Then you’ll see it reflected in sleep, it sounds like. Your sleep will start to get sloppy and non-restorative. Can you talk about that, the experience of sleep and the various stages that we go through and just tie it in again to your overall structure.

Dr. Sara Mednick: Yeah. Actually, the words upstate and downstate come from sleep science. In the past 15 years, one of the biggest discoveries of sleep science is that we have these things called slow waves. They are the deepest part of your sleep. It is the time when your whole entire brain basically turns on and shuts off over seconds at a time when you’re in, what’s called slow wave sleep. That’s the first part of sleep.

Those slow waves turn out to be the most restorative part of sleep. They’re the part where your brain is the most tuned out to the rest of the world and the world out there, and all the signs and symbols and everything that keeps us focused on the upstate. It’s the time where your body can go into repairing muscle tissue, conducting memory consolidation and laying down these long term memories. But also doing all the lymphatic clearance of cleaning out the toxins, that if they don’t get cleared out, they can lead to the plaque that lead to dementia and Alzheimer’s. Rebuilding proteins, all of these different processes can only go on during a super inward state, and that is the slow wave.

The slow wave has two parts. It has an upstate and a downstate. The really critical discovery was that the downstate is where all this important work happens. Then knowing about the downstate, it allowed me to say, oh, look at all these other downstates that we have. We have a downstate of the restore system where the upstate is rev, and then the restore system comes in, and how important it is for the downstate of sleep to co-occur with the downstate of the autonomic system.

That’s really when those two systems resonate with each other and they occur at the same time, you get this really powerful restorative sleep. That was a really exciting discovery.

Dr. Kara Fitzgerald: So exciting. It’s just so cool. In fact, I’m glad that you said it again, because I was going to circle back to that original statement, of your realization that moving into that full parasympathetic state is perhaps more important than deep sleep, or you need it to actually achieve-

Dr. Sara Mednick: That it happens, it needs to be at the same time. That it really needs to align with itself, which is a key point in when you eat, how you eat, when you exercise, how you exercise – all those things affect your sleep and your parasympathetic system. It’s really thinking about yourself as one whole system where all of the behaviors that you have during the day affect all of the outcomes that you want to achieve across sleep and overnight, and into the next day.

Dr. Kara Fitzgerald: It’s not just a matter of, don’t fight before bed, or I notice if I exercise too late, I don’t sleep as well. It’s like my whole day, the rhythm of my whole day is going to influence what happens when I go to sleep.

Dr. Sara Mednick: I think that’s really the magical step is to get out of the mentality that there’s a silver bullet. There’s one solution. If you just take this one supplement, or exercise in this one way, everything is going to change. Because it’s not. You are one whole system. Everything that you do affects everything else. Just thinking about it, in terms of rhythms is helpful, because that’s actually the way nature is created. Once nature finds a pattern that works, it just keeps repeating itself. You see this rhythmic quality to every aspect of our lives and just tapping into it can be really helpful.

Just thinking about sleep, I wanted to circle back to what you’re asking me. Once you go through that deep, slow wave sleep, there’s a good hour and a half to three hour period where you have the most amount of slow wave sleep. Then you have a decrease in slow wave sleep, and what you have is an increase in rapid eye movement sleep.

In the morning, you have a lot of rapid eye movement sleep or REM sleep. That’s really critical to think about is that REM sleep is driven by the circadian rhythm, meaning that it’s going to turn on, however much sleep you’ve had, you’re going to get REM sleep at a certain period of time of day, which is why you really need to think about what time of night you’re going to sleep in order to get in the slow wave sleep that you need before the REM sleep, circadian rhythm happens.

Dr. Kara Fitzgerald: Interesting.

Dr. Sara Mednick: Yeah. Which is why one of the action items I always talk about is try to get to sleep early, because you can’t control what time you wake up, a lot of the time. What time you wake up doesn’t really have an effect on your health very much. It’s really your bedtime that has an effect on your health because that’s what enhances the amount of slow wave sleep that you have.

Dr. Kara Fitzgerald: Well, that was a game changer for me. I write about sleep in my book and I struggled with sleep a lot and really put a massive amount… Actually, there were just little micro hacks that added up to getting good sleep. It wasn’t some miracle epiphany that I just learned how to sleep.

Dr. Sara Mednick: What did you do?

Dr. Kara Fitzgerald: Well, I think one of the biggest ones was going to bed on time, minor detail. Actually going to bed on time. I go to bed pretty early these days. Anywhere between 9:00 and maybe 10:30 at the latest. But probably on average, 9:30, that was the game changer, and that meant that… Well, I wear an Oura ring, which I’m pretty addicted to, and I don’t know how accurate it is and I would like-

Dr. Sara Mednick: It’s pretty accurate.

Dr. Kara Fitzgerald: Is it?

Dr. Sara Mednick: Yeah. We use them in the lab as well. Yeah, they’re pretty accurate.

Dr. Kara Fitzgerald: You do? Awesome. That’s great. Wow, that’s really nice to hear. Okay. I can see that I get more deep sleep, the earlier I go to bed-

Dr. Sara Mednick: Yeah, that’s so great.

Dr. Kara Fitzgerald: If my day is a little bit saner and a little more structured with exercise and we’re going to talk about nutrition. But it also means that I don’t have to set an alarm either. It’s awesome, I just want to underscore the fact that yeah, if we’re going to bed really late, for whatever reason in our life, we’re going to kick into REM and we’re going to completely miss deep. I just want to underscore that for folks to listen, because we are understanding, people are reading and paying more attention to sleep these days, I think, or to the science of sleep.

We know that deep sleep is important, but just this little fix of going to bed early. Other things for me that we’re essential is making my room really dark, keeping it really cool, not having big pillows. What else? Being mindful about the light, not eating. Just really making sure that I respect an intermittent fasting structure so that I’m going to bed not hungry, but not having just consumed food.

I don’t drink, so that’s not an issue. Being really mindful about when I stop my caffeine. I love coffee. So, I do have coffee in the morning, but then there’s a hard stop. All these little micro packs, add it up to good sleep.

Dr. Sara Mednick: They totally do. It’s amazing that it sounds… I guess the thing is, in some ways it’s like, okay, but everyone’s heard this. Nobody does it. Why don’t they do it? I feel like the reason why people don’t do it is that they haven’t been given a good reason as to why. That’s really what the point of my book was, is to give people the big why. How does your biological system interpret light? Here you go. Here is exactly why shutting off all blue light after 6:00 PM will tell your body it’s time for sleep.

Why does your body want a consistent schedule? Here’s why, we have circadian cells, we have these very rhythmic cells and your body prepares you for when you give it a consistent schedule. It prepares you for what is to come and it’ll help you get to sleep, it’ll help you be stronger when you exercise, it’ll help you metabolize your food faster, if you keep a consistent schedule.

I feel like people have heard all those different things that you just said, but unless you feel like you really know why you’re doing it and you have the big picture in mind, I don’t think people use them, but they really do work.

Dr. Kara Fitzgerald: I want to say for me, I understood the importance, just given my background and my training. But honestly, this is going to sound sort of corny. There’s, I’m sure a better way to language it, but it’s like I had a low sleep self-esteem. I had struggled with sleep, it was such an issue for me, such an issue. When you go night after night with insomnia, of course it kicks in poor mood and low energy and depression.

Dr. Sara Mednick: Poor self-control. Sticking with habits.

Dr. Kara Fitzgerald: Yeah. All of it. I felt so discouraged, like I’ll never be a good sleeper. That became my self-talk. For all of these super obvious micro hacks to add up to a good real night’s sleep, and in fact, extend, to go back to your first book on napping, I can nap now a little bit. I can do these little power naps-

Dr. Sara Mednick: That’s awesome.

Dr. Kara Fitzgerald: … in the middle of my day at work and just get up and just-

Dr. Sara Mednick: Reset.

Dr. Kara Fitzgerald: Yes. It’s extraordinary. There’s been this really lovely benefit. I wanted to just throw out one other thing and get your thought on it that’s helpful for me. There is an app that I’ll listen to sometimes. He’s counting backwards, there’s a little bit of rain in the background and he’s counting backwards from 999. I barely have it audible. It’s just noise in the background, and that is helpful. What do you think about that?

Dr. Sara Mednick: I think it’s absolutely part of the habit formation. I remember when I was pregnant and I wanted to have a natural birth. I did the hypnobirthing, which is that you’re just supposed to listen to this woman as you’re going to sleep. She just is telling you nice things that you’re going to sleep, but it’s the same tape and you’re supposed to listen to it every night.

I would turn it on, and her first like, and something, whatever she said, and I was out. Because you hypnotized yourself to, this is your cue. Your body’s looking for cues. This guy’s voice, what he’s saying, everything, your body’s like, oh, great, she’s doing that again. Great. I know exactly what to do. Then your body responds. It’s the randomness that catches our bodies off guard. It’s the eating at different times that can make us not be fit. It’s the stresses where we least expect them or the stresses that we can’t control. The uncontrollable stresses that are the most disturbing for our sleep, and that keep us up at night, which is why the pandemic was so scary for people, is because there was so much out of our control-

Dr. Kara Fitzgerald: Right.

Dr. Sara Mednick: … and so many new things that we couldn’t get used to. It was so hard to find our rhythm in a place where suddenly there was no rhythm to know. We had to set up our own rhythms. Then, in fact, a lot of people responded really well to that, because if they didn’t have children that were driving us crazy through the pandemic, a lot of people actually found their own rhythms. I think that a lot of people are finding it really hard to get back to the “real world,” because they did have an opportunity to listen to what is their natural state and sleep when they wanted to and take naps and exercise when it was right for them. That was an amazing little moment there, even though there was a lot of terrifying, horrible things are also going on.

Dr. Kara Fitzgerald: Yeah, that’s right. That is interesting. Yep, it did let us experience something that we haven’t at all, perhaps.

Dr. Sara Mednick: Yeah.

Dr. Kara Fitzgerald: All right. I have a lot of questions for you, but I want to finish, we were just talking about what’s going on with sleep. Intense dreams, God, did I have a weird dream last night. Oh my God, that somebody was speaking to me in my ear. They had infiltrated… Anyway, I won’t even go into this dream. It was such a weird dream. It woke me up.

But what’s up with dreams and the benefit of the dreams? What about psychic dreams? God, Sara, forgive me, but I was listening to this NPR program on the radio yesterday, driving home from my mom’s house with my daughter. This woman was talking about, her dad was a sleep scientist actually, and he didn’t believe in psychic dreams, but she said, “He’s coming to me in my sleep every night, and he says this and this and this to me.” Anyway, that just popped into… Talk to me about REM and moving into dreams and what that does for us?

Dr. Sara Mednick: It’s the next frontier of sleep science. We just know so little about dreams, but I think that in general, what people are thinking is that dreams are kind of hypothesis testing opportunities. That we’re obsessively going over potential expectations. What will happen if I’m being chased by a wolf or what will happen if I get COVID or what will happen if somebody approaches me at a job in a weird way? Any of these… Or if this person suddenly starts to come onto me or if I’m attracted to somebody, what will happen if?

That’s the idea of where people think the dreams are coming from. They’re not directly necessarily related to what we’re doing in our day-to-day. You don’t see as many direct correlations with, I ate this meatball sandwich today, or I went to a baseball game today. So, I’m going to dream about that. It’s more this kind of back-of-the-mind questions that we have about, whatever it is that keeps us daydreaming. It’s very similar to our daydream, it’s very similar to mind wandering, and it’s in the type of things that we dream about, and it’s also not particularly productive in that kind of way that when we’re awake, we’re trying to really think rationally through things.

But it is, in some way, a subconscious meandering towards potential futures, potential things that could happen. It’s a really interesting time period. We dream in slow wave sleep as well, but they are different dreams. There are dreams that are much more practical and they don’t have that kind of fanciful quality that the dreams of REM sleep. They’re more like meditations, they’re thoughts rather than these flights of fancy that may or may not be productive that we have in REM sleep.

Dr. Kara Fitzgerald: That’s fascinating. The ones in REM are so… Well, it seems like they’re metaphorical. They’re generally rather odd. What about Jung and Freud, in current thinking in neuroscience, in dream science. Is there a validity in some of their ideas?

Dr. Sara Mednick: I think that the idea that we have these subconscious desires, I think that people do come around and say, “Well, yeah, that’s probably true. We do have things that we’re not supposed to say, and we do have some latent feelings that we don’t talk about that does come out in our dreams.” That’s probably that subconscious quality that, daydreaming stuff that you find yourself daydreaming stuff that you would never say out loud, that you would just go, “Oh my God, I really need to stop thinking about that.”

You can catch yourself doing that. I think that those things do come out in dreams as well. That you see that in like, oh my God, I can’t believe I had that dream. When you start saying that you realize that’s something that you wouldn’t necessarily do if you had your prefrontal cortex operating fully, which it’s not, during sleep.

But what it’s also doing… The Jung and Freud, I think to some extent, people don’t say, oh, it’s total cocka-poo poo. There’s a place for it, but the specific hypotheses that they were talking about, the archetypes of Jung and the sexual fantasies of Freud, I think people don’t necessarily think have a lot of validity, and that the really specific symbolisms, I don’t think people have ever found any consistent patterns around.

Dr. Kara Fitzgerald: What do we do with our dreams, just out of curiosity? I used to write them down and the more I wrote them down, the better I was at recalling them. Is that a habit that’s worth engaging in? What would I do with it? Do you have any thoughts on that?

Dr. Sara Mednick: I think that they can be used for creativity. I think that they definitely can be used for creating more conscious linkages with your subconscious. I think that’s a really… I wake up in the morning and if I don’t have to take the kids to school that morning, I will do morning pages, and that’s just three pages of just writing without stopping writing.

It’s very similar to… A lot of the time what comes out is what was just occurring in my mind before I woke up? It’s writing out the… You’re not supposed to read this stuff. You’re just supposed to write it out and put it away. It’s not a diary that you go over and say, oh, on this day, I did this. I have books and books and books of pages I’ve never read before that I just wrote once and put it away. It’s just that idea of creating a space between the subconscious mental state and the, okay, here’s me being proactive and being directed and being prefrontal cortex-y during my day.

It just gives a little bit of honor to what just happened? You just spent whatever, seven hours in some state that was very different from the waking state. I think it can be very helpful in that transition and just being in touch with those kind of feelings and thoughts. There’s a lot of creative, scientific discoveries, music, artistic discoveries that have come from dreams. That’s another way that you can leverage the dream space. I think it can be super powerful.

Dr. Kara Fitzgerald: Yeah. I hear you. In fact, it reminds me of a physician who I shadowed when I was in my own training, and she was just this amazing scientist. She was just such an extraordinary human. She brought fluorescent antibody testing in the early ’50s to the fore and she figured out how to use it, and she was just doing just extraordinary work.

But later on, she had a lab that I was able to just live in her house for a little while and just shadow her at the lab, and she was just extraordinary. Joanne it would occur. She was running big, high powered, very well-funded labs in the ’50s and ’60s. She said that her best ideas came from dreams. She said, “I would never tell anyone in my lab that’s where my ideas came from.” But her hypotheses, the area of investigation that they would head into, she said came from her dreams. Isn’t that interesting?

Dr. Sara Mednick: Well, Friedrich Kekulé who won the Nobel Prize, in his Nobel speech, he talks about that his discovery came from his dream.

Dr. Kara Fitzgerald: That’s right. We’ve heard that. That’s right.

Dr. Sara Mednick: It says a lot about our society today that we don’t-

Dr. Kara Fitzgerald: That we would keep it to ourselves.

Dr. Sara Mednick: We don’t pay attention to sleep. Medical school students are not explicitly taught sleep. There’s no emphasis of sleep on its own. There’s some pulmonologist can talk about sleep apnea. This is something that we do a third of our lives and medical school students do not learn about it. It is the most natural healer that we have. When you go to a hospital, you’re kept up every three hours from all the beeps and the checks and in a hospital environment, there is zero honoring of sleep.

Dr. Kara Fitzgerald: Yes.

Dr. Sara Mednick: It doesn’t surprise me that you have to be secretive about listening to your own dreams because, medical science doesn’t even listen to our sleep as being… Sleep is like the greatest wisdom that we have in terms of healing, but that’s not what’s taught in medicine.

Dr. Kara Fitzgerald: I’m glad that you and other voices are changing that conversation. We’re becoming really excited about our wearables. I was just at a conference, teaching at the Institute for Functional Medicine, and three of us were doing a little Q&A, and all of us, very cutely had our Oura rings on.

Dr. Sara Mednick: That’s funny.

Dr. Kara Fitzgerald: Isn’t that funny? We’re just really embracing having this additional information. I find it really, really inspiring. Okay. On this note about what we’re not taught in medical school, speak to me about nutrition.

Dr. Sara Mednick: Yeah. That was the chapter and the whole section of the book that I knew least about. I didn’t really know that much about exercise either because I’ve just been studying the autonomic nervous system and sleep and circadian rhythm. It was such a joy to dive in and just understand what is the relationship between eating and the autonomic nervous system? And eating and sleep and eating and melatonin and eating and circadian rhythm.

It turns out, we are one system. What you eat has a direct effect. When you eat, you actually have an inflammatory response, you have a rev response. Every time you put something in your mouth that your body literally responds as though, is this a foreign thing? Is this something bad or good? Should I go to war? Should I mount an inflammatory response and have an immune reaction? Or is this healthy for me?

It’s a profound thought, when you think about it, that every time you eat, you are increasing a rev response. That means that you actually need to, every time you eat, also consider what you’re putting in your mouth. Is that going to increase rev more than you should? What time are you eating, and of course, what are you eating? Is it going to have a super huge blip in rev if it’s ultra-processed and has lots of sugar, or is it going to be a whole food that takes a long time to process and is a slow process that doesn’t spike your sympathetic response?

I thought that was really interesting. It also put all of those intermittent fasting, time restricted eating, there’s so much data to show how good different types of fasting routines are. But I feel like none of these explanations really ever tell you why they work. When I understood eating to be just another rhythm, and that this rhythm interacts with all your other rhythms, that it suddenly made sense. When you fast, you’re giving your metabolic system a downstate. When you continue to eat, you are basically exhausting your insulin system. You’re exhausting your ability to mount a response to this food coming in and create enough insulin and process your food. Across the day, insulin just decreases.

If you’re eating at 9:00 PM, you’re much less able to process that food and you leave a lot more of the glucose in your bloodstream than if you ate that same food in the morning, when you’re in your upstate, your metabolic upstate. Understanding how nutrition is… Eating is just another form of a rhythm that you can align with all your other rhythms, for me, it was a huge light bulb that went off. Knowing that, when you eat in the morning, you have an earlier onset of melatonin. When you try to actually eat a majority of your food during the day before the afternoon, you have an earlier onset of melatonin, the later you eat the later your melatonin onset.

Dr. Kara Fitzgerald: Interesting. Wow.

Dr. Sara Mednick: Everything affects everything. That was mind-blowing when I discovered that.

Dr. Kara Fitzgerald: It’s amazing to me, and is that because you’re in rev?

Dr. Sara Mednick: Yes.

Dr. Kara Fitzgerald: You’ve just thrown your rhythm off.

Dr. Sara Mednick: Yes. You’re basically waking the beast. It’s spent its whole day doing what it should, and it should be ready for a long, mini hibernation. But suddenly is a roar, I got to mount a response, a defense response to this new incoming piece of chocolate.

Dr. Kara Fitzgerald: Right, and this bag of Lays chips with a Netflix binge or something. No wonder we’re so-

Dr. Sara Mednick: Messed up. Exactly.

Dr. Kara Fitzgerald: We’re in alignment with these core practices, the data on biological age and negative changes to gene expression, is clear with sleep. The body of research in humans is just growing. Insomnia is pro-aging, profoundly as is stress, which is so intimately connected in what you’re teaching to sleep. They’re both not being highly stressed and not sleeping is extraordinarily pro-aging. In fact, after doing my research, I wonder if stress isn’t the biggest variable? I’m not sure. They’re all very important and they’re so deeply intertwined.

Dr. Sara Mednick: But I think that the more we can harness the intentional prioritizing of downstates as we age, I think that, that is the… As we talked about your daughter has it inborn, she doesn’t have to work on it. But as we’re getting older, that the stress increases, and our response to stress increases. It’s a golden rule, for every upstate stress response, you need to have a downstate restore response. You need to have something that combats what you just went through. Then you can achieve that right ratio, that good balance.

Dr. Kara Fitzgerald: That’s right.

Dr. Sara Mednick: Or else it just creeps in as this chronic state of this ratio that’s out of balance, where you’ve got over rev and under restore.

Dr. Kara Fitzgerald: Yes, and you’re just dragging through life. A friend of mine actually emailed me commenting on something that I had said around stress. He said, “You really need to distinguish good stress. You need to put some energy into that, beneficial stress. Stress is hormesis, turning on physiologic processes that make us more resilient.” I said, he’s absolutely right. I’m glad to be able to bring that into the conversation. It’s the wave crashing. It has to crash for us to be able to really fully restore.

Dr. Sara Mednick: The newer thinking about stress that I was really excited about and put into the book, is that idea that your friend said, there’s eustress, the good stress, and then there’s distress. We just use the word stress, but what we should be using is, eustress. Your daughter’s going to have to learn how to read and write, and it’s going to suck. It’s really hard to learn how to read and write, and it’s really hard to learn how to use good penmanship. It’s really hard. It’s really hard to tie your own shoelace.

Those are all eutresses. Buying a house just outside your financial comfort zone is a eustress. Those are things that build us. They actually make us feel like we can handle life, that we can do it ourselves, and they build a stronger frontal cortex. The frontal cortex is the thing that helps us to control our rev responses. There’s so much naturally, in life, that is helpful for creating that good balance between rev and restore. It’s only when you don’t have enough restore, or you’re in a situation where there’s chronic stress, be it from systemic racism, poverty, malnutrition, microaggressions in your workplace, all of these things that build up across the day. Then at night, if you’re not spending a lot of time processing and being good to yourself and getting to bed early and meditating and thinking through all of this stress that you’ve had, it doesn’t go away, it just builds. That’s when the out of balance ratio becomes chronic stress.

Dr. Kara Fitzgerald: That’s right. Very well said. He also mentioned caloric stress. A little bit of time restricted eating or a full fast, or the stress of exercise, or a sauna or doing some cold bath or something like that. Those are other forms of stress that are anti-aging. We were talking… It’s important to distinguish that. These stresses will help resolve the damaging stress that you pointed out of poverty, of racism and so forth.

Dr. Sara Mednick: But it’s also those particular groups that have the least access, that, that’s the systemic aspect of it is that there aren’t enough public parks in poor neighborhoods. There aren’t enough grocery stores in poor neighborhoods. There aren’t enough messages to downstate, there aren’t enough accesses to downstate. The systemic aspect of it is that the rich people get richer, in terms of downstate and the poor people stay poor and sick.

Dr. Kara Fitzgerald: Yeah. Of course, we see this reflected quite painfully in health outcomes, most recently with COVID. All right. As we just move into the home stretch with some of these thoughts. Just thinking about the institutionalized racism and some of the conversations that happened really next to COVID, I think we have been starting to shine some light in these clear inequities and may we all continue so that we can all learn from getting in… All of us become capable of actually having an opportunity to downstate.

Dr. Sara Mednick: I think it’s going to really be beyond the individual. I think it’s really on municipalities, it’s on governments to understand that if you don’t fund public parks, if you don’t fund education, if you don’t fund good nutritional programs and sleep education and exercise education, it doesn’t matter how much you tell people to do it, it’s not an opportunity that they have.

I think, as much as individuals are looking at themselves and how they contribute to these things, that’s not where it’s going to happen. It’s going to happen at the government level of really shifting who gets the money and for what? I think that’s something that really would be helpful for corporations to incentivize good eating strategies, to incentivize exercising. Not just saying you should do this, but saying, I will pay you to do this.

Dr. Kara Fitzgerald: There is some, I think, a nugget of movement around the recognition by the FDA of nutrition being a viable intervention in certain medical conditions. That could be a step towards opening nutrition as an actual prescription. We’ll have to see where that goes.

Dr. Sara Mednick: Yeah.

Dr. Kara Fitzgerald: What else do I want to ask you? You’ve already answered it, but you talk about, obviously, nature being essential. Any thoughts on that, that you want to add?

Dr. Sara Mednick: Yeah. That’s another incredible opportunity that I think is underrated. Just the fact that we really are animals. As much as our Teslas and our Netflix, and all of the different amenities in our lives that make us try to think of ourselves as being outside of the natural world. But we really do need nature. There’s so many benefits to taking the walk outside, taking the walk in a forest or taking the walk on the beach or going to whatever park you have to take your walk, rather than being in a gym or in whatever concrete space you’re in. If you could take it to a natural setting, people exercise longer when they’re in nature. People exercise with each other more when you’re in nature, you go for a walk with people so that you also get that community connection.

There’s immune responses that are stronger when you’re in nature than when you’re not in nature. In so many ways is this “green exercise” incredibly in important for our natural systems to, and you’re exposing yourself to natural light, which is what the circadian rhythm is really looking for is what’s the light source? If you stay indoors, you’re not getting that natural light message into your brain. Definitely, I think if we can really push for bigger investment in parks or getting people to take more time, take once a week, get out of a city and get into a nature world or spend your time in the park rather than in a gym, I think there’s so much evidence that’s a better alternative.

Dr. Kara Fitzgerald: I absolutely agree. In Connecticut, you know winter, because you come up to the Hudson Valley. We’ve had a pretty long winter this year. I can see the influence on my wellbeing. Just the trudge to the office, I’m a cyclist and it’s just not great time to be outside. Although, last year, I really tried to stay out as long as possible, and then dressing for winter became such a pain that I just gave in, and I started riding inside, which is definitely better than not riding at all.

Dr. Sara Mednick: Yeah, for sure

Dr. Kara Fitzgerald: I can absolutely feel the influence on my wellbeing, not being soaked in nature. I want to just… Listen, we have to wrap up. We’re totally over, but I want to ask you one more question about heart rate variability. You touch on it in the book, but should we be paying attention to ours? I know that, again, we can access it on the Oura and of all my numbers, it’s my weakest link, I’ll admit. Do I need to be putting intention on improving it and just, what are your thoughts on heart rate variability in your work?

Dr. Sara Mednick: We use our heart rate variability all the time, because it is a direct measure of your restore function. As much as, I think, the Oura does a pretty good job of measurement, but I think if you want to really be using a heart rate variability as an indicator for what type of exercise you should be doing that day, or, how you’re feeling on a day-to-day level. I don’t know if the Oura is going to do it. You might need to get one of those real bands that really does get… like a respiration band or a band that goes across the chest, to get the true sense of say, your resting heart rate before you get out of bed, just check what’s your heart rate variability at?

It takes five minutes and it just gives you a sense of when I did that hardcore bike trip yesterday, what am I ready for today? Did my restore response finish its final push all the way to getting back to a baseline? Or am I still in some sort of high rev response, and I need to spend another day just doing a slow walk? I think that there’s a lot of benefit to… Particularly for athletes, for sensing where you are across each day and letting that be a guide.

I had this amazing opportunity to interview Glover Teixeira, who became the MMA middle light… Gosh, some weight championship of MMA. He’s the downstate maven. He’s really a guy who, he was 36 and he was trained to be just go balls to the wall, hardcore fighter and was falling apart at the age of 36 when most fighters fall apart and stopped, and most people retire at that point. He hadn’t become world champion yet and he wanted to become world champion.

So he started reading about spiritual practice and he started reading all sorts of books about resting. He went to a specific training camp called the Performance Institute, which is basically all about measuring heart rate variability and heart rate to use as a guide to tell you whether you need more recovery or whether you’re ready to go hard again.

For the most part that is totally an antithesis of what MMA fighters think about because they just go hard all the time. But when he started doing this new training and started, he talks about it as his chill, really getting into his chill, the training program that they would give him would be like a third of what he used to do. He felt embarrassed about it because he felt like he was underperforming and he felt guilty about how little training he was doing. But the results were amazing.

He suddenly became a world champion fighter. At 41, he won the belt, became world champion at the age of 41. He’s the oldest first world champion in history. He says, and I believe him, it’s because of this paying attention to the downstate, paying attention to his chill and paying attention to his recovery process.

Dr. Kara Fitzgerald: That’s amazing.

Dr. Sara Mednick: A lot of it has to do with his heart rate. I think that there’s a lot of secrets in that, that we have yet to unlock.

Dr. Kara Fitzgerald: Yes. Yeah, absolutely. I remember Lance Armstrong, and doping notwithstanding, but talking about how athletes don’t take recovery seriously, and when I was competing, I didn’t, and I ended up burning out. Trying to be in the rev all the time. He said, that’s what us amateur athletes like myself do, and I did that. I absolutely did, and then I face planted. But yes, I’m inspired with your comments on using heart rate variability in that way. I think it could be really quite useful. Well, listen, Sara, it was just lovely to spend time with you. We could keep going-

Dr. Sara Mednick: I know. It’s so great. Thank you so much for having me on your show. It’s been so much fun to talk with you.

Dr. Kara Fitzgerald: Keep me posted on your research. It’s needed in this space. The way that you’re fusing, just bringing together, unifying so many different areas that we know are essential and bringing this whole picture, this whole person approach to sleep. This 24 hour day, or this line… Just the way that you’re thinking about sleep is lovely, and it resonates with me quite a bit.

Dr. Sara Mednick: Thank you so much. I really appreciate it.

Dr. Kara Fitzgerald: As always, thank you for listening to New Frontiers in Functional Medicine, where our sponsors help bring the very best minds in functional medicine, and today is no exception. Not everyone can be a sponsor on my platform, and I so appreciate the good work, relentless research, and generous support from my friends at Biotics, TA Sciences, and Integrative Therapeutics. These are brands I know and trust in my own clinic and can confidently recommend to you. Visit them at BioticsResearch.com, TASciences.com, and IntregrativePro.com, and please, tell them you learned about them on New Frontiers.

If it’s not too much to ask, I would appreciate a thumbs up and a kind review wherever you listen to New Frontiers. Thanks.

Dr. Sara C. Mednick is Professor of Psychology at the University of California, Irvine, where she directs the Sleep and Cognition (SaC) lab. Her first book, Take a Nap! Change Your Life put forth the scientific basis for napping to improve productivity, cognition, mood, and health. A world-renowned scientist, Dr. Mednick’s lab investigates the mind and body mechanisms that support performance improvement. Her work has been continuously federally funded with grants from the National Institute of Health, National Science Foundation, Department of Defense Office of Naval Research, and the Defense Advanced Research Projects Agency (DARPA), a United States Department of Defense agency. She has been interviewed by every major magazine and newspaper, including the New York Times, New Yorker, Los Angeles Times, Washington Post, and BBC, and has been featured on Good Morning America, among others. She resides in San Diego, and with her wife in the Hudson Valley.

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