#144 – Resilience: How well does your body respond to stress? | Dr. Taylor Sittler & Tom Griffin

The current ways of measuring health are limited: lack of disease isn’t enough. Resilience is a way to measure how well our bodies work now, and continuous monitoring can show us how well our bodies handle stress and subsequent recovery. Levels Head of Partnerships Tom Griffin sat down with Dr. Taylor Sittler to talk about how our bodies respond to stressful events, how functional medicine compares to traditional medicine and how gathering quantitative data around resilience can help us better understand our health.

04:07 – Understanding the state of the body

Dr. Taylor Sittler said that what brought him to Levels was his interest in learning how organs communicate with each other and how data and feedback could inform our understanding of health.

And after my work at Color, I’d been steeped in genetics for a long time. And I felt like I was starting to really understand human variation. But I didn’t really understand the state of the human body. What you deal with in genetics is predispositions and differences in certain proteins that might put you at risk for different diseases. But where people are in that disease state requires other types of information. And that’s where I really got interested in hormones, hormone monitoring, looking at how the body, the different organs signal to each other how things are working. It’s this incredibly complex symphony that I got really interested in trying to measure to see if we could marry that with the genetics to tell people more useful information. So started a company in women’s health, trying to fill a niche in menopause where there are a bunch of women who don’t get good advice from their doctor, and they don’t get the basic healthcare that they need. And that’s actually where I first came across Levels. We were going to do a study together. And I was really interested in Level’s approach. I think the laser focus on getting data and looking at feedback for people and being able to establish that feedback loop was really attractive to me. And I think the way that Levels has approached the whole concept of metabolic health has been really helpful. And those were the two big things and reasons I got interested in coming to Levels. And I feel like it’s a very promising way to look at the human body and to change maybe the way we practice clinical medicine.

06:27 – Your body’s response to stressful events

Resilience is a lever that helps your body recover more quickly from stressors, providing a helpful indicator of your overall health.

The way I defined resilience is it’s your body’s response to stressful events. We don’t get to control what events we have to deal with in our lives, but we can have some input into how we respond to those things. And increasingly I would argue that watching how your body responds to let’s say a night of no sleep or a difficult conversation with your boss or a really tough workout or something like that, understanding how your body responds to that tells you a lot about your general state of health. And the way that I came to looking at resilience was before I joined Levels, Levels has always, I think, been focused on trying to improve people’s health rather than trying to detect disease. And so I wanted to start to come up with metrics that would be indicative of health rather than of disease. And I think for a couple of different reasons, resilience really struck a chord there. And looking at how your body is stressed and how it responds to that stress is actually a great way to tell how your health works. If you’re in a situation where you’re not diagnosing a particular disease, we’re not trying to diagnose cardiovascular disease or diabetes or Alzheimer’s or things like that, in the absence of those diseases, having a framework for looking at how your body responds to stressors tells you a lot.

10:14 – Connecting physiology with diagnosis

If healthcare providers built more resilience testing into their regular diagnostic testing, we could better monitor how well people recover from stressors.

You also see the medical establishment use the idea of resilience in some of the testing they do. So for example, an oral glucose tolerance test is effectively looking at your resilience. You take this big slug of glucose, and then you see how the body responds to it, and you check your glucose level a little bit afterwards. As folks get older and they tend to have coronary blockages, they’ll do treadmill tests. So you go to the doctor, and you run a short amount of time with basically doing an EKG while you’re doing it. And that gives you a lot of information about how the heart responds. So this idea of resilience is actually built into some of the diagnostic testing that people do already. It’s just not a core part. People don’t think about the physiology when they make the diagnosis.

12:06 – Traditional medicine limbo

If you want to understand your health but you don’t have a disease, traditional medicine has no way to help you.

The traditional approach looks at basically, if you don’t have some diagnosable disease, then you’re healthy. And that’s actually kind of hard to swallow. And it also means that you’re not going to be able to help anybody until they have a real problem. Until they’re experiencing symptoms or they have a disease. The medical system won’t intervene. So that leaves a lot of folks with problems that are not easily diagnosable in limbo. It also means that you can’t get ahead of these problems and treat them when they’re best treated.

14:02 – Helping people achieve the health they want

You can engage more people in their health when you help them create their ideal lives.

The other piece of this is trying to link what people want in their health with what is “good for you”. So when I talk to people in their 40s and 50s, what they want a lot of times is more energy. They want to be able to do better at a workout, spend more time with their kids. And that involves being able to go a night without sleeping and then spending time with those kids. It involves being able to respond better to those stressors. So what resilience really does for me is two things. One, it focuses the diagnostic process in functional medicine. And two, it helps correlate with what individuals actually want in their health. Because when you talk about being healthy, it’s hard to get people to do much about it. If they’re like, “Hey, I’m not sick. I’m not going to do much.” But if you can say, “Look, this thing that we’re doing here is going to help you improve your workout. It’s going to help you have more energy for your kids.”, even for people who aren’t sick, they’re willing to engage in something like that. So those are the two reasons I think resilience is really important.

20:07 – A functional medicine approach

The modern functional medicine approach to healthcare already incorporates more peripheral testing and questioning to discover the source of a problem rather than only treating symptoms.

If you were to go to a functional medicine doc, they would try to think about, “Okay, what’s the process that’s happening in your eye? What are the things around that that we can test? How do we identify some of those things?” Where I think resilience could be helpful here is that in and of itself might actually be a stressor. So there’s probably something happening in your immune system that’s causing your eyelids to be inflamed. And whether that’s something in your diet that you’re eating or it’s some other behavior that’s tipping your immune system in one way or another, starting from the point of looking into that really can help us solve it. I don’t want to say that resilience is going to help us solve everything, but having this new lens to look at the system functionally and to stress it in different ways can help us identify problems.

24:12 – Correlating the measurements

Measuring the right units is important, but deeper insights only come when you can correlate all the results and look at them as a whole.

Heart rate tells you a lot about strain, recovery, how you’re sleeping. Temperature can be really helpful also. Well, one, it could tell you about … You see coordinate changes in heart rate and temperature that drop during the night, and that gives you a sense of what stage of sleep you’re in. Additionally, we’re finding that for instance, if temperature goes up in the evening, that may be an indication that you’re getting sick. So there are ways to detect that. I think what’s really exciting and what the future looks like is correlating all this information so we can give you a much better sense of how you’re responding to things. And that’s really where resilience comes in. Like, what stressors is your body dealing with right now? How could we expect your insulin resistance to look like in the morning?

27:21 – Standardizing the stressor

Measuring your reaction to a stressor is a great way to understand resilience, but it’s also complex. The more standardized, the more valuable the measurement.

I think the thing that’s missing today is some level of standardization in measurement. WHOOP does try to give you a score, which is good, but there’s not a sense of trying to standardize the workout or standardize the stressor. Whereas, I think Peter Attia, for instance, with the grip strength, like how long can you hang from a bar. So that’s pretty standardized. So I think that’s the first part is being able to standardize the stressor that you’re going through and then looking at how your body responds. I think, yeah. WHOOP does give you some indication of your resilience. I think your heart rate variabilities correlate with resilience. I think your ability to recover and your recovery score is important. It’s just incomplete information. Because there are a couple of different, important factors that determine where you are going into that workout. You want to try to control for those things as well. So I think it’s going to be important to measure a few other things that we’re still figuring out in order to get a true sense of your resilience.

30:12 – Resilience vs. adaptation

Resilience is a function of how your body recovers, but adaptation describes how your body may change over time to deal with constant stressors.

There’s resilience, and then there’s adaptation. If he was 22 and he was able to do that, he might have actually been highly resilient. And I don’t think there’s a negative health association with being highly resilient. But what often happens, if you take that 22-year-old and now you zoom ahead to when he is 40, he might still be able to handle a bunch of drinks and wake up without too much sleep and go to work, but now that’s an adaptation that his body’s gone through because it’s gone through this a number of times. And usually what you find with adaptations is that there are consequences. So for instance, one of the things that often happens with people who drink a lot is they get high blood pressure. They don’t sleep well, they get high blood pressure. And once you have had several episodes of that high blood pressure, your vessels get used to … They start to thicken, and this becomes a self-fulfilling prophecy. It takes more work then to push the blood through those blood vessels and the high blood pressure stays. And so probably, that guy might still feel really resilient at 40 because he can do this thing that’s been associated with resilience, but he’s actually not. He’s actually just his body’s gone through an adaptation because it knows what to expect. And I think those two things are worth picking apart

36:48 – The love hormone

Oxytocin corresponds to your feelings of connection, and correlates to life expectancy. If we can better measure oxytocin levels, we can better understand how it contributes to a long and happy life.

One easy way to think about it is you get these oxytocin boosts when you feel like you’re socially supported. You’re feeling a strong connection to the people around you. And what we’re finding is that connection, it directly correlates with longevity. So it’s one of the big things that does correlate with how long you live. And this can be … We need to do more work. I mean, I think to be fair, what I like about measuring oxytocin is I feel like it’ll give us a quantitative way to assess this. But we’ve known for a long time that, for instance, people who go to church more live longer, particularly in their older age. And it seems to be because they have more social bonds. Folks with partners tend to live longer. People who feel like they’re connected to their community live longer. Once we can start measuring that quantitatively and correlating that with the longevity, it gets really exciting.

Taylor Sittler: (00:06)

The way I define resilience is it’s your body’s response to stressful events. We don’t get to control what events we have to deal with in our lives, but we can have some input into how we respond to those things. Increasingly I would argue that watching how your body responds to let’s say a night of no sleep or a difficult conversation with your boss or a really tough workout or something like that, understanding how your body responds to that tells you a lot about your general state of health.

Ben Grynol: (00:45)

I’m Ben Grynol, part of the early startup team here at Levels. We’re building tech that helps people to understand their metabolic health. And this is your front row seat to everything we do. This is a whole new level.

Ben Grynol: (01:11)

Resilient. It is a word that gets thrown around often, and sometimes we need to take a mental leap into what does it mean for our bodies to be resilient. So, Dr. Taylor Sittler, Head of Research and Development at Levels and Tom Griffin, Head of Partnerships, the two of them sat down and discussed this concept of resilience. Taylor has been digging into the concept for some time and really starting to think about how does the body bounce back so quickly from certain things like high glucose levels? How does the body bounce back and repair itself from something like an acute injury, maybe a paper cut, something really small? But it’s the idea of the body being really good at repairing itself if the conditions are right, that being the food, the diet, the lifestyle choices that are made to help the body be resilient. So the two of them, they sat down and they discussed resilience and what it means from a metabolic health standpoint. Here’s the conversation with Tom and Taylor.

Tom Griffin: (02:14)

I think it would be helpful to just set the stage in terms of why you and I of all people are having this conversation. I do marketing and partnerships at Levels and by no means am a health or scientific expert. And you in fact are an expert, at least by education and certification as a medical doctor and head of clinical and research at Levels. And the goal here is to take a layman like myself and pick the brain of an expert and maybe translate a more complex scientific topic for a general audience. And the topic today is going to be resilience, which we’ll get into shortly. But let’s just start by … Give us a brief overview of your background and how you came to be interested in this space and Levels.

Taylor Sittler: (02:58)

I guess, by training, I’m a mix of software development and medicine. I’ve pulled those things together in a few different ways. I did my residency in clinical pathology at UCSF. Initially did a bunch of work in sequence analysis and pathogen detection. So being able to identify any pathogen from a human sample, early outbreak detection and things like that. Then I moved … For somebody who was a computer geek, math geek, and a doctor that was a nice mix. From there, I was doing my residency at UCSF, went over to Berkeley and worked with a bunch of computer scientists to try to speed up the way that we would analyze genetic data because there were getting to be big analysis backlogs and it was taking months to be able to give people results on different types of genetic testing.

Taylor Sittler: (03:49)

That led to me syncing up with a couple of serial entrepreneurs and we started a company called Color, which now does both genetic testing, so we were able to drop the cost of testing to make it much more affordable and available hopefully, primary care, and then also now doing COVID testing. And after my work at Color, I’d been steeped in genetics for a long time. And I felt like I was starting to really understand human variation. But I didn’t really understand the state of the human body. What you deal with in genetics is predispositions and differences in certain proteins that might put you at risk for different diseases. But where people are in that disease state requires other types of information. And that’s where I really got interested in hormones, hormone monitoring, looking at how the body, the different organs signal to each other how things are working.

Taylor Sittler: (04:49)

It’s this incredibly complex symphony that I got really interested in trying to measure to see if we could marry that with the genetics to tell people more useful information. So started a company in women’s health, trying to fill a niche in menopause where there are a bunch of women who don’t get good advice from their doctor and they don’t get the basic healthcare that they need. And that’s actually where I first came across Levels. We were going to do a study together. And I was really interested in Level’s approach. I think the laser focus on getting data and looking at feedback for people and being able to establish that feedback loop was really attractive to me. And I think the way that Levels has approached the whole concept of metabolic health has been really helpful. And those were the two big things and reasons I got interested in coming to Levels. And I feel like it’s a very promising way to look at the human body and to change maybe the way we practice clinical medicine.

Tom Griffin: (05:52)

Awesome. Let’s dive into the topic at hand here, which is resilience. And this is a topic that we’ve become interested in at Levels. We’ve started to talk about it internally, write about it, and this has been spearheaded by you. So you’re leading the clinical strategy over the next five years. So maybe let’s define resilience and then also I think it might be interesting and useful to talk a little bit about how did this even come up internally at levels and what got you interested in starting to talk about this?

Taylor Sittler: (06:27)

Yeah, definitely. The way I defined resilience is it’s your body’s response to stressful events. We don’t get to control what events we have to deal with in our lives, but we can have some input into how we respond to those things. And increasingly I would argue that watching how your body responds to let’s say a night of no sleep or a difficult conversation with your boss or a really tough workout or something like that, understanding how your body responds to that tells you a lot about your general state of health. And the way that I came to looking at resilience was before I joined Levels, Levels has always, I think, been focused on trying to improve people’s health rather than trying to detect disease.

Taylor Sittler: (07:18)

And so I wanted to start to come up with metrics that would be indicative of health rather than of disease. And I think for a couple of different reasons, resilience really struck a chord there. And looking at how your body is stressed and how it responds to that stress is actually a great way to tell how your health works. If you’re in a situation where you’re not diagnosing a particular disease, we’re not trying to diagnose cardiovascular disease or diabetes or Alzheimer’s or things like that, in the absence of those diseases, having a framework for looking at how your body responds to stressors tells you a lot.

Tom Griffin: (08:01)

Interesting. One thing that’s striking me right now that I hadn’t thought about until that response, it seems that a lot of the measurement and diagnostics that we currently can get our hands on are point in time metrics. And frankly, even something like a continuous measurement of heart rate or glucose most of the time is in isolation. And what I mean by that is it’s not in response to a behavior or a stressor. And it seems like something unique maybe about measuring resilience in particular is you’re always looking at a particular stressor or behavior and how your body is responding. And I think there’s something more meaningful about that and potentially even more interesting. And I’m thinking about a recent Peter Attia podcast where I listened to it, I don’t know, maybe a month or two ago, but I remember he brought up a grip strength test, like just hanging on a bar as one of his number one tests that he does with clients to determine strength.

Tom Griffin: (09:05)

But then it also is maybe … It’s highly correlated to longevity and disease prevention. I remember I was on the edge of my seat and I was like, “Oh my God, give me the time. How long am I supposed to do this thing? Because I’m going to go to the gym tomorrow and hang on a bar.” And it was a rude awakening that I think of myself as a reasonably fit guy, but I think Attia was saying he hangs for two minutes and I got to like 45 seconds and my hands were shaking. But anyway, it was incredibly useful because I could take an action and then see what happened rather than measuring what feel like an endless amount of arbitrary metrics.

Taylor Sittler: (09:43)

Yeah. Yeah. I think we see this in … I mean, Peter, I think is really on the cutting edge and I think he has a similar outlook. From what I understand, actually, it’s grip strength and leg strength. It’s kind of deadlift. Sorry, not deadlift, but a squat. Those are the two things that correlate best with longevity.

Tom Griffin: (10:05)

Interesting.

Taylor Sittler: (10:06)

And again, we see this both … I think Peter uses this and there’s a fair amount of literature on that, but you also see the medical establishment use the idea of resilience in some of the testing they do. So for example, an oral glucose tolerance test is effectively looking at your resilience. You take this big slug of glucose, and then you see how the body responds to it and you check your glucose level a little bit afterwards. As folks get older and they tend to have coronary blockages, they’ll do treadmill tests. So you go to the doctor and you run a short amount of time with basically doing an EKG while you’re doing it. And that gives you a lot of information about how the heart responds. So this idea of resilience is actually built into some of the diagnostic testing that people do already. It’s just not a core part. People don’t think about the physiology when they make the diagnosis.

Tom Griffin: (11:04)

Got it. Yeah. Simply put, it strikes me as a potential way to quantitatively measure health. That is what we’re after here. We don’t want to just cross our fingers that we avoid a disease diagnosis at some point, but we want to know where we stand today and we want to know how healthy we are today. And I guess, walk me through maybe what are the current ways we might try to measure health and why are those not great relative to maybe introducing a new concept like resilience and expanding the ways that we can measure something like resilience? Is it just that we don’t have a cohesive way of thinking about health?

Taylor Sittler: (11:53)

I think if you look at the … Maybe let’s start with the traditional approach and then we’ll move to there’s a more modern, functional medicine approach that I think Peter has expanded, and then we’ll add resilience at the end. The traditional approach looks at basically, if you don’t have some diagnosable disease, then you’re healthy. And that’s actually kind of hard to swallow. And it also means that you’re not going to be able to help anybody until they have a real problem. Until they’re experiencing symptoms or they have a disease. The medical system won’t intervene. So that leaves a lot of folks with problems that are not easily diagnosable in limbo. It also means that you can’t get ahead of these problems and treat them when they’re best treated.

Taylor Sittler: (12:41)

And I think there’s a lot of people talking about this now. So moving into an approach where you test and you diagnose prior to a disease is really where we all … So that’s how we’re improved over the traditional model. The modern model, I think … Well, or the functional medicine model, which has been developed over the last 20, 25 years, most prominently by Mark Hunt, looks at a series of … They started mostly with a series of lab tests and thinking through how your body is actually functioning and using some of those tests to help guide treatment even ahead of disease. And I think that’s been tremendously helpful. This has been talked about elsewhere. What I think that lacks is this focus on the stressor, which is what you just brought up. When you go to a functional medicine doc, they’re not going to ask you to run on a treadmill.

Taylor Sittler: (13:34)

They’re not going to say, “Hey, when you did this thing yesterday, when you were on your workout yesterday, how did that go?” And the reason they don’t is because, A, it typically requires more equipment. You’d have to measure some stuff. And B, it’s not a central part of that diagnostic philosophy. So what I’m trying to do here is put a focus on the stressor as an important part of the diagnostic process. I think it’s also … The other piece of this is trying to link what people want in their health with what is “good for you”. So when I talk to people in their 40s and 50s, what they want a lot of times is more energy. They want to be able to do better at a workout, spend more time with their kids.

Taylor Sittler: (14:28)

And that involves being able to go a night without sleeping and then spending time with those kids. It involves being able to respond better to those stressors. So what resilience really does for me is two things. One, it focuses the diagnostic process in functional medicine. And two, it helps correlate with what individuals actually want in their health. Because when you talk about being healthy, it’s hard to get people to do much about it. If they’re like, “Hey, I’m not sick. I’m not going to do much.” But if you can say, “Look, this thing that we’re doing here is going to help you improve your workout. It’s going to help you have more energy for your kids.”, even for people who aren’t sick, they’re willing to engage in something like that. So those are the two reasons I think resilience is really important.

Tom Griffin: (15:14)

Yeah. That’s super helpful. And I think it’s such an exciting proposition that we might be able to measure this stuff, whether it’s through technology or it’s through just a better understanding of some of these tests we can do like grip strength. Which now that I’m thinking about it, it’s like, we could have some of these inputs even in the Levels app, which I think would be interesting to get a more holistic picture. But the ability to measure, I think, makes the concept real and coherent for people. Because without the ability to measure, it’s what you said, it’s sort of you’re shrugging your shoulders and you’re saying, “I have no definition in my mind of what health really is, other than I want to like feel good and I don’t want to get a disease.” And I’m thinking about the mental health space, which resilience is a term in the positive psychology space as well, which positive psychology started, I think in the ’90s.

Tom Griffin: (16:12)

It was Martin Seligman who was the famous head of the American Psych Association basically decided for the first time ever to take a different look at the field of mental health and psychology and say effectively, rather than only studying pathology, if our goal is wellbeing of people, might it be useful to also better understand what wellbeing actually is and what flourishing is? And if we can define what it is, we might be able to measure it. And then if we measure it, we can cultivate it. And if we can cultivate it, then you’ll have more resilience. And that’s where the resilience term came in back then. But they didn’t have measurement tools it was just self-report surveys and measuring things like how many positive emotions do you have on a daily basis, or relationships in your life, or meaning at work. Which I think held the field back a bit. But I think with physical health, there’s more quantitative measurements, which makes it really exciting.

Taylor Sittler: (17:17)

Definitely. And I’m hoping we’ll be able to incorporate mental health as well. I mean, it’s really affirming in a sense that when someone else was looking at this 20 years ago, they came up with resilience as the direction they were interested in. I mean, I’m interested in, for instance, if we can measure oxytocin. Can we actually see how people are feeling about their social connections? It’s getting that level of data that correlates with the positive emotions that correlates with the psychology. And I think there’s a bunch of work going on right now in metabolic health and psychology. People are doing experiments with keto diets and things like that. So I’m really excited to see where that field goes, but I’m hoping that will be in alignment with the work that we’re trying to do here in the more physical health space. But it’s super interesting.

Tom Griffin: (18:12)

Let’s get really tactical and specific here. Fortunately I haven’t had any like chronic diseases in my life, but I’m thinking about a time that I had a chronic issue that was beyond frustrating for probably, I don’t know, may have been seven, eight years. And essentially I had this eyelid issue that would come and go and you’ll know the name of it better than I will, but it’s something like chronic blepharitis or bleph … Is that it?

Taylor Sittler: (18:42)

You got it. Blepharitis.

Tom Griffin: (18:44)

Or at least that’s what they were … They shrugged their shoulders eventually and they were like it must be this thing. And once they just put a chronic label on it, I feel like everyone gave up. But essentially my eyelids would just get randomly irritated and red and it was a huge pain in the ass, frankly. But it would come and go and sometimes it would be worse than others. And I probably ended up going to between living in New York and San Francisco, maybe 12 doctors. And I kept looking for doctors with more credentials. I was like, “Okay, this one went to Stanford medical school and Harvard medical school.” I’m like, “They’re definitely going to know what they’re talking about.” And I’m not exaggerating when I say that every single doctor only had one recommendation, which was one or two courses of antibiotics.

Tom Griffin: (19:24)

And I’d go to each new doctor and say, “I’ve already done these antibiotics.” And they’d say, “Maybe just try it one more time and you never know, sometimes your body responds differently.” And I was like, “The last seven people told me that. It hasn’t helped. You must have something else to say about what … Look at my diet. Look at something. Ask me about exercise.” And it was fruitless. Anyway. It eventually went away and I don’t know why, which happens a lot. I guess walk me through … That experience was with the traditional healthcare system, which obviously sucked. What would be the experience in maybe five years from now, if a lot of doctors have internalized some of these approaches that we’re talking about?

Taylor Sittler: (20:06)

Yeah. Well, I think already, if you were to go to a functional medicine doc, they would try to think about, “Okay, what’s the process that’s happening in your eye? What are the things around that that we can test? How do we identify some of those things?” Where I think resilience could be helpful here is that in and of itself might actually be a stressor. So there’s probably something happening in your immune system that’s causing your eyelids to be inflamed. And whether that’s something in your diet that you’re eating or it’s some other behavior that’s tipping your immune system in one way or another, starting from the point of looking into that really can help us solve it. I don’t want to say that resilience is going to help us solve everything, but having this new lens to look at the system functionally, and to stress it in different ways can help us identify problems.

Taylor Sittler: (21:04)

And so I think rather than going through the medical algorithm and saying, “It’s not this, it’s not this, it’s not this. So most likely it’s a blepharitis. We’re going to give you a course of antibiotics. That’s really all we can do. Because there might be some bacteria that’s chronically getting in there that if we get rid of the bacteria, we’ll get rid of the problem.” That was the way they were thinking about it. functional medicine might say there’s a chronic inflammation problem in your body. A lot of people have that. And we can go into that separately. Where resilience might help is thinking about what specifically could we stress that would give us information about this? And I don’t know that I have a good diagnostic course for blepharitis.

Taylor Sittler: (21:53)

Starting from that point, I think could really help elucidate this problem. As well as what we’re seeing is the continuous monitoring of things like glucose or ketones or oxytocin or cortisol can give us a lot of information about the body and how it’s handling things. And so one of the first things I might do is just monitor a few things and see how you’re responding. As we build out larger and larger corpuses of this information, and we’re finally starting to do this with some work Levels, we’ll have a sense for how these continuous things might change and how they might tip us off that there’s a problem that we can address [inaudible 00:22:36].

Tom Griffin: (22:38)

On the note of hormones and additional molecules, let’s talk about the current state of measuring resilience. I have Levels, I measure glucose. I have WHOOP and Oura Ring, which are doing similar things. They’re measuring mostly overnight heart rate and heart rate variability, which HRV is a measure of stress, in theory. I’m curious, is this enough? And if not, what does the future of measuring resilience look like?

Taylor Sittler: (23:09)

Yeah. We’ve started looking at some of the scoring systems for glucose. We’re rethinking those a bit. And I think what’s interesting is this idea of resilience is now coming into how we score glucose traces. So for example, you might have a spike that goes up quickly and comes down quickly. That indicates your body is actually good at shifting in order to handle glucose load. For other folks, it might go up and stay up for a while. Or it goes up and down and you have a biphasic response. And in each of those cases, what you’re looking at is the body responding to a glucose load in a different way. And I think we’re going to start to be able to get very concrete about resilience by looking at different traces. So we’re looking at the glucose trace with Levels, which gives you some information about how the body is handling energy and how well it’s coordinated on that front.

Taylor Sittler: (24:07)

What I think WHOOP or Oura can do is give you heart rate and temperature information. And heart rate tells you a lot about strain, recovery, how you’re sleeping. Temperature can be really helpful also. Well, one, it could tell you about … You see coordinate changes in heart rate and temperature that drop during the night and that gives you a sense of what stage of sleep you’re in. Additionally, we’re finding that for instance, if temperature goes up in the evening, that may be an indication that you’re getting sick. So there are ways to detect that. I think what’s really exciting and what the future looks like is correlating all this information so we can give you a much better sense of how you’re responding to things. And that’s really where resilience comes in.

Taylor Sittler: (24:56)

Like, what stressors is your body dealing with right now? How could we expect your insulin resistance to look like in the morning? There was a recent study that showed that you eat the same thing two days in a row and basically there’s a 20 to 30% difference in your glucose level by eating the same thing. What that means is there’s all kinds of other contexts that goes into how your body handles that glucose. And I think even with just a WHOOP and a Levels monitor, we can give you a fair amount of that context. When we start measuring additional things, additional molecules, additional … There are different ways we can measure stuff. I think we’ll get a much better picture of how your body overall is responding to things. And that’s what to me is really exciting. So we could say, “Look, you look like you’re getting sick and you only slept four hours last night. We think your insulin resistance is going to be high. You probably would eat fewer cards today, or maybe think about skipping lunch.” How cool would that be if your app could tell you that?

Tom Griffin: (26:05)

100%. Yeah. Someone with all of the apps, it would be nice if someone was doing some more sophisticated data science on top of it than I can do in my head, which is pretty limited. One thing that’s striking me about WHOOP, I mean, I’m thinking about WHOOP, and in some ways, my first thought was like, “Oh, they’re measuring resilience.” Their recovery score. If you run a marathon, they’re looking at how you respond to that marathon in your overnight numbers. But I think what’s missing is baselining that to what response you would want. So for example, if I did a hard workout with WHOOP and then recovered really well, but I continued to do that hard workout three times a week and in three years from now, I was recovering much less well. Like 30 points worse on WHOOP. Is it fair to say that potentially I’m getting less resilient if I’m not able to handle that workout in the same way as judged by something like an overnight HRV metric? I know that you can’t totally answer that question, but what does your instinct say?

Taylor Sittler: (27:20)

Yeah. I mean, I think the thing that’s missing today is some level of standardization in measurement. WHOOP does try to give you a score, which is good, but there’s not a sense of trying to standardize the workout or standardized and stressor. Whereas I think Peter Attia, for instance, with the grip strength, like how long can you hang from a bar. So that’s pretty standardized. So I think that’s the first part is being able to standardize the stressor that you’re going through and then looking at how your body responds. I think, yeah. WHOOP does give you some indication of your resilience. I think your heart rate variabilities correlate with resilience. I think your ability to recover and your recovery score is important. It’s just incomplete information. Because there are a couple of different, important factors that determine where you are going into that workout. You want to try to control for those things as well. So I think it’s going to be important to measure a few other things that we’re still figuring out in order to get a true sense of your resilience.

Tom Griffin: (28:29)

Got it. I’m going to throw a hard question at you, but one that I’m really curious about. I historically have always been certainly known among my friends as being sensitive. I remember one friend calling me an orchid. That I need my conditions to be perfect in order to thrive in terms of how I sleep and what I eat. And some tangible examples of this would be if I get under seven hours of sleep, I feel exhausted the next day. And another example would be alcohol. My entire life, I will get the worst hangovers of anyone that I know. And I was given a hard time about this for a while, but then eventually what I started saying is, it was a joke, but I would say, “Listen, my body’s just so optimized that if you kick it off course at all, it knows what it wants and it knows what health is and so it rejects sleep deprivation, it rejects alcohol.”

Tom Griffin: (29:28)

And I would claim like I’m happy that my body knows it needs sleep. And then I’m thinking about another friend who’s the opposite. And truly, when he was 21 years old, we’ll make him the legal age for this story, he could go out and have 15 beers and truly, I’m not kidding sleep two hours and he’d be on the Peloton or doing a half marathon the next morning at 7:00 AM and feel totally fine. And I’m wondering, is there any version of being highly resilient that might not be a sign of health? Just take my friend who can sleep one hour a night and drink all night and feels fine the next day and … You know.

Taylor Sittler: (30:10)

Well, I think there’s resilience and then there’s adaptation. If he was 22 and he was able to do that, he might have actually been highly resilient. And I don’t think there’s a negative health association with being highly resilient. But what often happens, if you take that 22 year old and now you zoom ahead to when he is 40, he might still be able to handle a bunch of drinks and wake up without too much sleep and go to work, but now that’s an adaptation that his body’s gone through because it’s gone through this a number of times. And usually what you find with adaptations is that there are consequences. So for instance, one of the things that often happens with people who drink a lot is they get high blood pressure.

Taylor Sittler: (31:07)

They don’t sleep well, they get high blood pressure. And once you have had several episodes of that high blood pressure, your vessels get used to … They start to thicken and this becomes a self-fulfilling prophecy. It takes more work then to push the blood through those blood vessels and the high blood pressure stays. And so probably, that guy might still feel really resilient at 40, because he can do this thing that’s been associated with resilience, but he’s actually not. He’s actually just his body’s gone through an adaptation because it knows what to expect. And I think those two things are worth picking apart, if that makes sense.

Tom Griffin: (31:47)

Yeah, definitely. I think that’s a really helpful distinction and one that I’ll bring back to that friend next time he tells me that he’s healthier than me because he gets on the Peloton at 7:00 AM after a night out. All right. So age is a factor. Do you tend to get across the board as your instinct that you get less resilient over time?

Taylor Sittler: (32:08)

Yeah. I think we see this. Recovery takes work. Mitochondria tend to wane as you age in terms of their function. Sinclair talks a lot about this. You also have changes in epigenome, senescent cells, cells aren’t functioning as well. So your body isn’t … Because it’s not functioning as well, it actually, when you tip it in one direction … This is why the resilience part is so important. When you push the body in one direction or another, it doesn’t come back as quickly. So they don’t respond to the stress as well. And yeah, I think we see that across the board. Whether you’re looking at glucose or cortisol or a number of different things, you can measure it both in individual molecules as well as I think you can see it overall with gray hairs and lack of energy and stuff like that.

Tom Griffin: (32:58)

Got it. So it tends to go down over the course of a lifetime and then zooming in a little bit over the course of say, let’s look at a five to 10 year period. Maybe where there is an onset of a chronic disease developing in someone. Is it fair to say that you’re more resilient at the start of that onset than you are towards the end? Which is in part why it’s so important to be able to measure some of this stuff so that you can intervene.

Taylor Sittler: (33:31)

Yeah. I mean, I think by definition, once you’ve started experiencing symptoms … So in cardiovascular disease, the symptoms might be chest pain or they might be shortness of breath or in diabetes, it’s going to be the tingling in your feet because the nerve endings aren’t working anymore. Once you’ve hit that point, your body’s probably already gone through a couple of adaptations and you don’t feel the same anymore. So I think you’re definitely less resilient for most diseases.

Tom Griffin: (34:02)

Got it. What is your best guess at rough timeline for when it will be relatively mainstream to have wearables that can predict with decent accuracy when you’re developing many, if not most of the chronic diseases? Because it seems like that’s where we’re heading eventually.

Taylor Sittler: (34:26)

Well, I mean, I think it’s going to take time. I mean, really you have to get physicians to change the way they think about things and that can take decades.

Tom Griffin: (34:36)

How about the technology though?

Taylor Sittler: (34:38)

The technology’s there. I feel like the technology is going to be there within five years.

Tom Griffin: (34:43)

Really?

Taylor Sittler: (34:44)

And actually a lot of it’s there now, it’s just not put together.

Tom Griffin: (34:47)

Oh, wow.

Taylor Sittler: (34:48)

Medical studies take a little while to do. Rightfully so, we’re very cautious about doing these things. And the main reason is that, look, you don’t want to hard people who aren’t sick. If you develop a sensor that causes inflammation in a number of people, or creates some toxic side effect, that’s a problem. So we do want to proceed slowly and do this in a way that is going to hurt the minimal number of people. But I think the concepts and a lot of the technology to do this are really out there. What we need is going to be more. It’s a change in the way [inaudible 00:35:26].

Tom Griffin: (35:27)

Got it. Interesting. That’s optimistic. In terms of the fact that much of the technology is already here, that’s exciting. But I hear you on the other stuff.

Tom Griffin: (35:39)

What two molecules are you most excited about one day being in the Levels app that you can measure in real time?

Taylor Sittler: (35:49)

I mean, to me, measuring fatty acid metabolism and measuring lactate are interesting, but those are already in process. There’re a bunch of companies that are developing those. The two that I think are most interesting are going to be cortisol and oxytocin. Because once you start to make these correlations between psychological behavior and physiological behavior, I think it’s going to open up holy realms. People are going to choose who they work with or who they date based on their psychological profile or based on their physiological profile. They’re not going to attend the weekly call with their in-laws. There’s a bunch of stuff that’s going to change when-

Tom Griffin: (36:35)

Most people know cortisol is the stress hormone, but briefly define oxytocin.

Taylor Sittler: (36:40)

It’s called the love hormone. It has a prominent role in maternal physiology. But basically one easy way to think about it is you get these oxytocin boosts when you feel like you’re socially supported. You’re feeling a strong connection to the people around you. And what we’re finding is that connection, it directly correlates with longevity. So it’s one of the big things that does correlate with how long you live. And this can be … We need to do more work. I mean, I think to be fair, what I like about measuring oxytocin is I feel like it’ll give us a quantitative way to assess this. But we’ve known for a long time that, for instance, people who go to church more live longer, particularly in their older age. And it seems to be because they have more social bonds. Folks with partners tend to live longer. People who feel like they’re connected to their community live longer. Once we can start measuring that quantitatively and correlating that with the longevity, it gets really exciting.