Dr. Kevin Tracy (2:38)

The vagus nerve is a nerve that starts in the base of your brain at about the level of your ears and travels down your neck, across your chest, into your abdomen. And along the way, it sends us. It sends branches our fibers out and touching all the organs you never think about. Now, now we call it the vagus nerve, but you actually have two of them, like two thumbs and two kidneys, etc. And these two, two nerves on each side are even more complicated than that, because within Each of these two nerves in humans is 100,000 fibers, 100,000 individual nerve fibers. So when, when, when you talk about your vagus nerve, you actually have 200,000 of them. And all day long, the signals traveling up and down from your body to your brain in the vagus nerve, and then back down from your brain to your organs. These signals are the fundamental basis of reflexes that operate to keep your organs functioning in a harmonious, healthy way. In other words, your heart and your kidneys and your lungs, they're all working all day long in a balanced, harmonious way when you're healthy because of reflexes traveling largely in the vagus nerve.

Ed Mylett (3:57)

Gotcha. And that matters why? Let's dive deep into some stuff here, just for some basic stuff. I think it's been established sort of in the medical community the last decade or so that inflammation is probably the root of most disease in the body. You correct me for all the things I say that are wrong today because there'll be a bunch of them. But assuming that's sort of become the new foundational basis for what most people believe about disease in the body, that matters why, as it relates, first off, is that probably true? And if it is true, why does that matter in relation to the vagus nerve inside our bodies?

Dr. Kevin Tracy (4:33)

It is true. And just to make it very concrete for those who might be interested, every year on the planet Earth, about 6, 60 million people die. According to the WHO. Two thirds of those deaths are caused by conditions that you just alluded to, sort of chronic diseases that can. That, that kill. Two thirds of. Of people who die every year include cancer, heart disease, stroke, diabetes, metabolic syndrome, obesity, and neurodegenerative. Conditions such as Alzheimer's disease and Parkinson's. So, as you alluded to correctly, what those conditions all have in common is that inflammation either causes them or contributes to them by making them worse. And so the question that I've been thinking about for going on 40 years now in my laboratory at the Feinstein Institute in New York is what is it that that drives inflammation at the level of molecules, individual molecules and cells? And how can we use that information about what's driving inflammation in the body to stop inflammation? Now, in the late 80s, 1980s, my colleagues and I made some contributions to developing molecules that stop inflammation in many patients. And those molecules today go by the name of biologics. And you see them advertised on the nightly news, you see them advertised on all the Sunday football games. These biologics are. Many of them are monoclonal antibodies. And they, they bind, they stick on cytokines, which are molecules made by white blood cells. And these cytokines can cause inflammation. So that's what we've known since the 1980s. And these, these drugs are very powerful, and they, they treat patients with conditions like rheumatoid arthritis and, and other conditions, but they don't cure. They don't cure the disease. So some, some other things are still going on. And so the fact that these biologics don't cure inflammation, but can slow it down taught us that these molecules are very, very important in causing inflammation. But I found myself years ago wondering, well, if. If the immune system has the. And our bodies have the ability to make this. These powerful inflammatory molecules which can cause harm, it can cause serious damage to your organs if there's too much inflammation, and it can contribute to these other illnesses that can kill so many people every year on the planet earth. And the real question I had was, how does the body normally control inflammation? Now, if you take what we just talked about from the vagus nerve, and I said, reflexes are controlling the healthy balance of your organ functions known for over 100 years or more, that reflexes traveling in the vagus nerve control how fast your heart beats. If it beats too fast, signals in the vagus nerve slow it down. Reflexes in the vagus nerve control how much insulin your pancreas makes and how much glucose your liver can produce. So if this is what we've known all along, the question to me became, well, if reflexes are doing things to all the other organs, is it possible that reflexes in the vagus nerve are also controlling inflammation? That was the Eureka idea. That was the Eureka moment. But as you know from the book, we don't say eureka in the lab anymore. We say holy shit.

Ed Mylett (8:18)

Right everybody, we're going to cover so much today that. But we're going to talk about trauma here in a second too. So there's so much to this inflammation, vagus nerve, the sympathetic nervous system. There's so much to it, you guys, that over the next five years you think AI is a revolution. And by the way, it even fits inside this discussion. This is going to be a revolution. I'm telling you. It's been part of my work for a long time on just performance and well being. But so one more foundational thing I just want to lay out there is there used to be this adage that, you know, Plato said a long time ago, you can't heal the body without healing the soul, right? And there's this adage, there's a lot of, you know, growing up there were these, you know, theories of, well, if you're, if you've got trauma and you're under great stress, you're going to, you know, you're going to die younger. And that was kind of theoretical, but now we actually know, don't we? So explain to us a little bit foundation and then we're going to get into some great stuff. How does trauma, anxiety, trauma in our life or anxiety or things that happened in our childhood or in our lives actually affect this inflammation in our body? Like you've, you've essentially, we've proven this now. So give us the correlation of why unhealed trauma is detrimental to your physical health, not just your mental health.

Dr. Kevin Tracy (9:41)

So Plato, Plato was right. I happen to agree with him. And, and, and your quote from him is spot on. If you think of the signals traveling in the nerves as controlling all your organs, then the fundamental discovery of the link between the vagus nerve and inflammation that we made was that the vagus nerve is sending signals that act like the brakes on your car. So if, if inflammation is, is barreling down the hill and there's nothing and the brakes fail and inflammation spins out of control, then all kinds of problems will occur. So we, we can take that now as a fact and the revolution that we're coming into and living through as we speak, as of six or seven weeks ago, on the day that we're recording this, the FDA approved the basis of this idea as a new therapy to treat inflammation in patients with rheumatoid arthritis. And I think you're right. I think this is launching a whole new era in medicine. Where bioelectronic medicine will begin to replace drugs.

Ed Mylett (10:44)

So that's, that's a big statement.

Dr. Kevin Tracy (10:47)

It's a big statement, but it's backed by the facts and it's kind of fundamental, as you said, laying the fundamental groundwork to this conversation. When, when you look at the, the role of, of childhood trauma and inflammation and long term health, the, the results are absolutely fascinating. And I know that you've talked about this in the past on your show and you've read these papers, but one of my favorite studies that nails the point of this is if you look at elderly graduates from college and gave them a survey and said, okay, what was your father's income when you were, I forget, four, or between four years old and 10 years old or something like that. And so these people filled out the survey and they made an estimate of whether they were rich or poor by their by based on their father's income when they were little. And then the researchers measured salivary cortisol in these patients and what they found was a near perfect correlation inverse between their father's income and how much salivary cortisol was present, meaning how much stress their body was carrying throughout all those decades of life. Five, six, seven, eight decades of life. The lower the income, the higher was the cortisol in the saliva. So what does that mean? That means that the nervous system, the brain, which controls the pituitary gland and the pituitary adrenal axis, that makes steroids the nervous system, it carries an engram, it carries a memory or an imprint of the stress that occurs when you're young, and that can be translated back to the body, in this case through signals in the pituitary adrenal access. But if you look at other indicators that say heart rate, resting heart rate, or resting heart rate variability, there's evidence. And those, sorry, those, those are controlled by nerve signals, not hormonal signals. Right. So signals in the vagus nerve, which is parasympathetic, and signals in the sympathetic nervous system either accelerate or decelerate the heart. That balance lives in, if you will, in the brainstem, in the brain, and that turns out to be influenced by childhood stress. And those effects can last for many, many years. So if signals in the nervous system can be modulated by childhood stress, that's a fact. And if signals in the nervous system can turn on or turn off inflammation through the vagus and sympathetic nerves, and that's a fact, then the answer to your question is yes, there's definitely a relationship between stress nervous system Control of inflammation and how much inflammation you bear in your body, which of course then can put you at risk for complications in your organs from too much inflammation.

Ed Mylett (13:40)

Let's talk about how that might work. By the way, isn't this fascinating, everybody? And by the way, there's ways, everyone, pretty simply that you can actually see how you're doing with this stuff. So let's. Let's use me for a second. Okay, so first off, everybody, give yourself the gift of just learning a little bit about the sympathetic nervous system. We're not going to get too much into that today just because there's too many other things to cover. But let's just call the sympathetic nervous system for the layman. You're in a fight or flight mode to some extent. So take a guy like me. I grew up with some childhood trauma, alcoholic father, got sober when I was 15. But those first 15 years were a lot of anxiety, a lot of stress, a lot of worry. Also in my family, I think a little skosh of mental health issues, little maybe Scotia depression. And they're like a touch, you know what I mean? And so I think I grew up in a fight or flight mode in my sympathetic nervous system. I wasn't parasympathetic very often. Now I find myself at 55. I've had some health issues in my life and my resting harm. I'm fit. I work out five days a week, I'm in the gym. I've got low body fat. I've. I've been fit most of my life, yet my resting heart rate's almost 80 and my HRV is incredibly low. Like last night was 11. Most nights it's like 15. Does that mean those two metrics, you can educate them on HRV as well? A little bit. Does that mean, is that indicative that I am probably in sympathetic nervous system mode and not parasympathetic most of the time? Is that what that would indicate? In other words, high heart rate, low hrv? Is that indicative of somebody that's in fight or flight mode most of the time?

Dr. Kevin Tracy (15:32)

More than likely, there are some that would say that to you, that yes, it is. I'm not sure I would be much more honest and say maybe before I drew a conclusion. Let me back up a second. The problem with some of these things is when all the data fits with a dogmatic idea, it's very easy to jump on the answer being the dogma. The problem is when you scratch the surface of the dogma and try to understand where do these definitions and measurements come from. You realize that you kind of run out of data really quickly. So in the case of measuring fight or flight, you would want more than just knowing your resting heart rate and your heart rate variability. You really would also want to know your hormone levels and levels of, you know, cortisol is one we talked about a minute ago. You want to know your cortisol levels. You would want to know your norepinephrine or epinephrine levels. Those are very hard to measure. They have to often measure the byproducts or the metabolites of those in either blood or urine. You'd want to have a much more sophisticated analysis, and you would want to have it over long periods of time for many days in a row. So think of the example of diabetes patients worried about measuring her glucose levels. And she's a diabetic. She might take a glucose measure at some random time of the day and see it's perfectly normal, and then go ahead and have whatever, a candy bar or an orange, and then not measure until, till sometime later and see that it's still normal. So, okay, I don't have diabetes. But if she measured her hemoglobin A1C, which integrates the glucose levels over many, many hours, days and weeks, she would find that the hemoglobin C was off the charts because the glucose was spiking intermittently. We don't have quality measures for inflammation, frankly, or for sympathovagal balance. There are some that advocate for using heart rate variability as a gold standard of sympathovagal balance, but that's also actually much more controversial than you would ever figure out from looking at social media. What is heart rate variability? So if you look on an ekg, you see each heartbeat, or if you feel your pulse, you feel a distinct beat of every heart in your wrist or your neck. If you actually have a stopwatch and measure the time between individual heart rates, you can write down all those times in sequence, and then you get a long sequence of numbers that are called instantaneous heart rates. Now, when the vagus nerve fires, it prolongs the time to the next heartbeat. That's why vagus nerve slows your heart, because it prolongs the time between heartbeats. If you have a lot of vagus nerve activity, and that's happening frequently now, you have, you can subject these data which, which can be obtained on EKGs, for instance, or Holter monitors, where you can follow EKG signals for many, many minutes or hours. You can add up and analyze with statistical algorithms all of these instantaneous heart rates. And you can derive predictors that guide us to what we call heart rate variability. And people refer to this as vagal tone. If you look at the high frequency domain, after sort of a Fourier transformation of these complicated data, there's a little spike which has been correlated with vagus nerve activity in humans. But is that the whole answer? Well, it depends on the algorithm. Right, so your Fitbit and your Apple watch and your other wearables, they're all using different algorithms and they're all proprietary. So one person's heart rate variability may or may not be being measured the same as another person's.

Ed Mylett (19:43)

Okay, everybody, I want to. I want to get you in the weeds here. We're going to talk about solutions here in a second and why it matters. So stay in here. And it does matter. Okay, so you say in the book that the brain listens to the body and then it talks back through the vagus nerve. And with the right tools, the body can heal itself. And it starts with the great nerve. So let's actually prove that. Let's talk about this. So I'd like you to talk about. This is going to blow your mind, everybody. But the work that's recently been approved as it relates, I think in the book I'm reading about arthritis, rheumatoid arthritis, and the work you've done. So he said something pretty controversial earlier, guys, which essentially is that I'll call them pharmaceuticals, but that essentially maybe electricity in the body and the ability to stimulate itself that way could replace or at least mitigate the use of pharmaceuticals. You go, no way. Well, actually, here's some studies and some evidence that will maybe begin to change your mind about this. So why don't you tell them a little bit about basic concept that, you know, the. The brain listens to the body and what you believe with the right tools, the body can begin to heal itself. And it starts with this nerve, give them that foundation. And then the work you've been doing with arthritis, it's just. Guys, you're not gonna believe this.

Dr. Kevin Tracy (20:58)

It's a fascinating observation that if you inject inflammatory molecules, molecules that produce inflammation in either a mouse or a man, that those molecules will cause the mouse or the man to develop what we call sickness behavior. So anorexia, depression, withdrawal, social withdrawal, these effects are very real, and you've all experienced them. If you've ever had a bad case of the flu where you just want to crawl in bed, you don't want to eat anything, you don't want to see or talk to anybody. You don't even want to engage in any hobbies because you just withdraw those molecules, those cytokines like TNF and IL1. They produce those effects because when they're in the body, the vagus nerve senses them. And the vagus nerve carries electrical signals from the body up into the brain that basically tell the brain, hey, there's a lot of cytokines in the body. And the brain's response is to produce that depression, that fatigue, that behavioral withdrawal and that anorexia. So this, this has been proved in animals because if you cut, if you cut the vagus nerve in animals, which you can do in mice, you can't do it in people. But if you. And then give those cytokines, the mice don't get sick. It's very remarkable. It's very remarkable. So what happens to those signals going up into the brain? Well, the brain is processing the incoming signals as too much inflammation in the body, and it sends signals back down the vagus nerve to turn the inflammation off. And that basic discovery which I alluded to before as the brakes, like the brakes in your car that are the brakes on your inflammatory response, that allowed us to write in the back of a napkin in 1998, well, if the vagus nerve is, is using electrical signals to turn off inflammation, we should be able to develop a, to engineer a biomedical device that we could implant on the vagus nerve to activate those brakes, to stimulate those signals. And those signals, once stimulated, would break or slow the inflammatory process. And so that was on the back of a napkin in 1998. We worked on this for six or nine years to prove to ourselves that it would work safely in animals. And in 2007, I co founded a company called Set Point Medical, which is the company that developed the device I just described and proved that it works. The device is about the size of a multivitamin or a fish oil pill. It sits under the skin, under the strap muscles in your left neck at about the level of your Adam's apple. And it delivers, for one minute a day, a small pulse of electrical activation at 400 microamps. I mean, it's almost nothing for one minute a day. Many of the patients actually sleep through this one minute a day. They don't even know the treatment's happening. But because this treatment activates the inflammatory reflex, which is what we call it, and turns off inflammation, what we're seeing is that in a clinical study of rheumatoid arthritis patients, now these patients were not benefiting from biologics they were not getting better. They still had severe disease despite the fact they tried all these powerful medications. And what we saw was that about 75% of them gained significant clinical benefit from having vagus nerve stimulation implanted in their neck. It's really incredible, actually.

Ed Mylett (24:34)

It is incredible. And you know everybody, there's so much done. Packer. This should be a four hour show, but it begins to make.

Dr. Kevin Tracy (24:41)

I got time, I got time if.

Ed Mylett (24:43)

You do, by the way, maybe we'll do multiple shows. But it starts to make you wonder, everybody, what are the other applications and implications of this vagus nerve stimulation, doesn't it? And I mean, are we going to have a world in your opinion someday? You said electricity over chemistry someday in the body. Do you think, you know, in the next five or 10 years you're going to see a world where we're running around with these chips stimulating our vagus nerve to help reduce or mitigate diabetes or rheumatoid arthritis, heart disease, cancer? Do you see a world like that or is that premature to say that that's possible?

Dr. Kevin Tracy (25:25)

I see a world very soon where many, many people with rheumatoid arthritis in the United States will have this as a therapy. I have met some of the patients. I have met Kelly owens, who spent 12 or 15 years in and out of wheelchairs using a cane which she no longer needs. I mean she gave me her cane. It sits in the corner of my office. Now her therapy is vagus nerve stimulation and she's now seven or eight, eight years out from, from the implant. So the effect is durable. I've met a teacher who has a, who has a, it's called an immunoregulator from Set Point, this vagus nerve stimulator in her neck and, and she said it wakes her up at 4:30 in the morning. I said I'm sure that, I'm sure the engineers can change it to stimulate your vagus nerve at later in the morning so you can sleep in. She goes, no, no, Kevin, I don't mind. I said, why don't you mind? She said, because I'm a teacher and for years I would wake up in the morning at 4:30 and with pain in my hands so severe that I would cry because I was afraid I wouldn't be able to get dressed to go to work or pick up a pencil. She goes, now I wake up at 4:30 in the morning and this thing buzzes and I smile because I don't have any pain in my hands.

Ed Mylett (26:42)

So you were careful there. I watched you, you were careful to say rheumatoid arthritis. I'm not asking you to predict, I'm asking you your opinion. Do you think that there's implications or applications in diseases beyond arthritis?

Dr. Kevin Tracy (26:56)

100% I do. I'm painting right now the fact that there's a pond cover covered partially in pond lilies, and we know the doubling time of the pond lilies and we know the surface area of the pond. I think you can make very concrete predictions about a significant use for rheumatoid arthritis in the US Based on the current FDA approval. Because of that, it's a baby step to look at other inflammatory conditions where we already have data either in humans or in laboratory experiments. In humans, there's very convincing data in small trials that will have to be repeated in larger studies for the treating Crohn's disease, inflammatory bowel disease and ulcerative colitis. There is very compelling animal results in multiple sclerosis. And I think you're going to see setpoint announcing, if they haven't already, clinical trials to treat multiple sclerosis. And that'll happen immediately. You know, if it's not open now, those trials will be open soon. You're going to see news about the possibility to use various vagus nerve stimulation based therapies to treat diabetes and potentially even metabolic syndrome or obesity. There's fascinating data about the relationship of vagus nerve stimulation to enhancing neuroplasticity, which is the phenomenon that can enhance recovery from injury and stroke. And the FDA has approved that indication already. There's fascinating data in treating depression. Hundreds of thousands of people have already received vagus nerve stimulation therapy for treating epilepsy and depression. Now what's fascinating to me about depression is it works really well, but only about half the time. So what is it about those 50% of patients that get better from vagus nerve stimulation therapy versus the 50% that don't, that has frankly slowed its use, its adoption into widespread practice? Prescribers don't like to not know the half. Right. It makes sense. On the other hand, some of the responses are people who were suicidal, unable to care for their families, unable to work. And now if they're in the half that respond, they're not suicidal, they're caring for their families, they're back at work. So what is the cost benefit of that? And my question in these kind of situations is, is it possible that the vagus nerve stimulation is reversing the inflammation that's causing the depression? So these are the kinds of questions that I Guarantee you're going to see a huge amount of new work being done in the next few years.

Ed Mylett (29:35)

Guys, is this crazy, by the way? In a minute we're going to talk about daily practices that you can implement that are simple to help stimulate the vagus nerve or potentially move you into parasympathetic mode here. But before I ask you that, I want to ask you, you know your take on these devices that are available in the market. They sit on your ear. I won't name them, but I've got four of them next to my bed right now. I've tried all of them. That are these devices that suggest that they can stimulate the vagus nerve by some stimulation on your ear. There's a couple that work on the neck, supposedly. What are your thoughts on those? Without.

Dr. Kevin Tracy (30:20)

As you know, because you read the book, I have a lot of thoughts on this and some, some are good and some are not so good. So let's just recall what I said in the beginning. You have a. You have two vagus nerves, but you actually have 200,000 vagus nerves. So it's complicated. It's complicated because each and every one of those fibers, 200,000 fibers, was honed and perfected by millions of years of evolution to start at a particular place in your brain or body and go to a particular place in your body or brain. So it's got its own path, it's got its own route, it's got its own destination and origin, and it has its own function. When someone says to me, I want to stimulate my vagus nerve, I say, you have 200,000. Which one do you want to stimulate? What we've done with the Setpoint device is we figured out that 400 microamps only stimulates a few hundred, maybe a couple thousand fibers. And those happen to be the fibers that stop inflammation. So that's the good news, right? A very low amount of current driven directly, placed directly on the vagus nerve can do a specific thing because it targets specific fibers. That's not true when you put electric current in your ear or on your neck. It's not possible to have the evidence in humans yet because we can't measure the vagus nerve electrical signals, which would be the ultimate proof that you've stimulated the vagus nerve. Unless you're putting a device on the vagus nerve. The reason people are interested in putting a device on the ear, for instance, is because there's a branch of the vagus nerve that goes to the cartilage of the ear. A small part of the cartilage, the outside of the opening to your ear. It's called the simvacantia. Now, that's a sensory branch, which means it's carrying information about what's happening in the cartilage into the brain, into your brain stem. And it happens to go to the place where all the other incoming information goes from, the vagus nerve. So that's interesting. And there's pretty good evidence from many studies that if you put a small amount of electric current using a TENS unit, a transauricular epidural nerve stimulator, that you can now put people in brain scans and you can actually show that the areas of the brain that are activated by a TENS unit in your ear correspond to many of the vagus nerve centers in the brain. So that, so far, so good. That's interesting. And then you can do clinical trials and you can study the effect of a TENS unit in the ear on all kinds of things. Opioid withdrawal, migraine headaches, inflammation in various conditions, whether it's Crohn's disease, we've done that. We've done arthritis associated with lupus, or you can do blood tests and look at inflammation, and we've done that. Now, what you see in these small studies oftentimes is some signal, you see less inflammation. That doesn't prove it's a vagus nerve stimulator. Okay. Once you drive those signals from the ear into the brain, the brain has 100 billion neurons and trillions of synapses or connections, so it can do whatever it wants with it. It doesn't mean that there's a direct path from your ear to your spleen to stop the inflammation that's headed to your intestines or your wrist. So that's where it breaks down, right? It's like correlation is not causation. Right? The correlation between some clinical benefit from doing something in your ear or your neck doesn't prove that it's a vagus nerve stimulator. Putting all that aside for a second, if you can afford to buy it, you know a half a dozen devices and play with them at different times of the day and night. If you like to self experiment, if your doctor says it can be safely done, that's all fine and good. But some people can't afford these six devices and they buy them because they're out of options and they're desperate and they're reading crap on some website, selling something that's exaggerating the clinical benefit. That's where I kind of recoil a little bit, because at the end of the day, you have to either understand the scientific mechanism of action, which I just explained is impossible, or very difficult with a TENS unit in your ear, or you have to have large, well controlled randomized clinical trials that have been validated by the fda. And in most cases, frankly, those things are just so. I wrote the book to explain all this, not to attack anybody, not to criticize anybody. And like you, I don't, I don't name the names of these devices because frankly, some of these, some of these non invasive devices do have interesting clinical outcomes and clinical results. They're just not vagus nerve stimulators. The only way to stimulate the vagus nerve is to put an electrode on the vagus nerve. This is your fix. I am your host, Stassi Schroeder. Welcome to Tell Me Lies, the official podcast. What's the most unhinged thing of season three? Steven.

Ed Mylett (35:24)

Because he's so evil, I do think he is misunderstood.

Dr. Kevin Tracy (35:27)

You see everyone face consequences.

Podcast Host/Announcer (35:29)

It's intoxicating.

Dr. Kevin Tracy (35:30)

The writers just know how to trick. Yeah, there's always a twist in this show. Tell Me Lies, the official podcast, January 6th. And stream the new season of Tell.

Ed Mylett (35:39)

Me Lies January 13th on Hulu and Hulu on Disney. I love your approach, by the way, and your, your, your demeanor. Talk about stuff that doesn't cost anything.

Dr. Kevin Tracy (35:50)

That's even more interesting. Right?

Ed Mylett (35:53)

So I'm going to throw two things at you. And they're not correlated, but they're two things I do pretty regularly. So by the way, and they're, they're. One of them's really in vogue. So what about prayer and, and these are completely disconnected things, but they both don't cost anything. And so prayer. And is that a biologic tool? Is it a spiritual tool? Is it both? So I'll give you these. Prayer slash meditation and just cold therapy in general. Just speak to those and why they matter or don't for you.

Dr. Kevin Tracy (36:29)

Let's do them in the opposite order, if you don't mind. Yeah, so I, I am a fan of cold therapy. A couple times a week, I'll put the shower on full cold at the end of my normal shower and I'll stay in there for a bit and let's just talk about why I do it and what I think's happening. What the ev. Not just what I think. What I think is based on studying the evidence, the normal caveat. Please check with your doctor. There are patients who should not do this without checking with their doctor to make sure that they don't have a fainting episode or problems with their heart. But what happens when you step in that full cold shower is it hurts, it's uncomfortable, all the air goes out of your body. You feel like you can't breathe. It's terrible. And people say they enjoy it. And I have a more nuanced view of that kind of enjoyment. And I wrote about this, I see you smiling. It's really much more like I've done it for now for several years, a couple times a week. And every time I step in that, because I step out of the hot shower, let it get cold and then step back in. And every time I step back in, half of my brain is screaming, don't do it, you fool. You fool, you fool. And then you step in and it's highly uncomfortable. And, and I'm not, I don't think you get used. I, it's not that you get, it's not that you get used to the discomfort, you're fully aware of it, but it just doesn't bother you in the same way. And the way I describe it is I feel like, boy, that person doing that cold water thing is really foolish and, and is really suffering and uncomfortable. But it's like I'm watching that person. Rather than fully experience. The first time you do it, you fully experience it, right? And, and I, and I highly recommend the first time you do it, you don't do it. You don't do full cold. There's no reason to get, you can work up to it over a period of days or weeks. Now that is fight or flight. You talked about it before, that's fight or flight. And what we, we know from, I mean, we've infused fight or flight hormones in human volunteers on shore leave and we've studied this in animals. The acute fight or flight, which is what's happening, your heart rate races, you've got that horrible feeling you can't breathe. Those hormones turn off inflammation. So for me, check the first box. If the whole idea is to have an anti inflammatory sort of experience, check that box. Then I stay there. Sometimes I hold my breath while I'm doing this and I stay in the cold until, I don't know, until I feel my heart rate slow down. And at that point I know I've stimulated the vagus nerve. I hope that the fibers to the heart are also. Because I've stimulated those and my heart rate slowed. I hope I've also stimulated the fibers to, to slow my inflammatory response in my spleen and elsewhere, but that's a little more Difficult to prove. And, and the studies on, on cold exposure, adapted cold exposure where people, there's, there's some studies from Scandinavia where they took soldiers, military types and they put them in a cold room, like 4 degree centigrade cold room and sprayed them in cold water and put a fan on them and they let them stay there for a long, long time. Some of those studies show pretty decent evidence that their heart rate slow down and their inflammatory responses are slowed down. So that's why I do it and that's how I put it together. The fight or flight, that acute stress response, that's a massive fight or flight response, that's anti inflammatory and then the cold adapted response is a vagus response and that's anti inflammatory. But you know, what about then the chronic stress you talked about earlier in the show in your own life and your listeners lives. Chronic stress is not really full blown fight or flight that we just talked about. Chronic stress is low grade persistent fight or flight. It's not the same thing. Low grade chronic fight or flight stimulates inflammation and that's really important. So you can have it both ways. Fight or flight can be good for you and that's probably what happens when you exercise. Exercise is a form of controlled good stress, controlled fight or flight. But it's that chronic gnawing away, eating at you, fight or flight at low levels that actually produce inflammation. So that's why I do the cold showers now. There's other ways of doing it and there's people advocating, you know, there's billions impression of web impressions on vagus nerve and cold, billions. And everyone's, some of them are based on good science and some of them have to be treated with a little bit more caution in their interpretation.

Ed Mylett (41:21)

What about prayer?

Dr. Kevin Tracy (41:23)

So prayer is complicated because it involves relaxation responses and it involves changes in your breathing. And so the simple answer is if you wanted to take it to the highest level as you suggested in the beginning of the show, if you check your pulse and you have a slow pulse during prayer, you've maybe you've stimulated your vagus nerve by the by by prayer. But you said, is it spiritual or not? Well that's hard to prove. But you can prove to yourself that by changing your breathing pattern you can slow your pulse. So you could do it right now, right? You can check your pulse and you can breathe in on three slowly through your nose. What happens when you take three sort of big breaths? Three seconds, one, two, three seconds. Usually some people advocate taking it as sniffing through your nose for three seconds. You Fill those lungs. You've stimulated your vagus nerve. But let's talk about that specifically. What you've actually stimulated are the sensory fibers of the vagus nerves from your lungs to your brains. Because you've expanded your lungs that stretch, the signals goes up and they tell your brain, okay, this guy or gal has filled their lungs. So you've stimulated your vagus nerve. Is that really the same thing as the fibers that go to your heart or your spleen? Not really. But then what happens after the signals go into your brain? Now you exhale for seven seconds and if you check your pulse, you'll feel it slow. That's called respiratory sinus arrhythmia. Now you're breathing on a 10 second cycle, three plus seven. And that would be six breaths a minute. If you keep doing that for a few minutes, you'll notice during exhalation that your heart rate has slowed because the signals from your brain are traveling down your vagus nerve to slow your heart. Now if that happens during prayer or any type of meditation or relaxation therapy, then yeah, it's a good thing to slow the vagus nerve, to stimulate the vagus nerve and slow your heart. Hopefully it that those, those methods are also slowing the amount of inflammation that your body makes. But it's very, very difficult to prove that it's not well proved.

Ed Mylett (43:45)

Isn't this good, you guys? All right, a few more things and I want everybody to go get the great nerve by Dr. Kevin Tracy. That's what you need to do. It's. I read it in two days and I wanted it to even be longer. It's not a book that when you're done, you're like, yeah, I went too many chapters. You even want more. It's that good. You guys, I want to ask you about this inflammation thing. And then I want to talk about heart and brain coherence. My friend Dr. Joe Dispenza talks about. So I want to understand this inflammation thing a little more. We're kind of going backwards, but we're not. My dad died. My dad got cancer in his early 60s and he lived for about eight years. He died in his early 70s. My dad was very fit, worked out all the time, ate clean, didn't drink for 35 years, quit smoking 40 years ago. And I was interested is the idea that when you have chronic inflammation in your body. Am I way off on this? My dad was a stressor. My dad worried like just you'd walk in a room. And I love him, but he'd almost, you know, he'd sign like, dad, what's wrong? I don't know. You know, just like that was his normal disposition, you know what I'm saying? And I would have loved to seen his HRV and his resting heart rate and all this other stuff. But is the idea that if you live in that mode, am I crazy to think that it may trigger some form of gene expression in your body prematurely? Meaning, and I know there's no proof of this, I just want your opinion. Meaning, you know, you're predisposed to get cancer, maybe it should have been triggered in your 80s, but you've just lived in this inflammatory mode all your life. And so this expression frankly cranks on younger and earlier in your life than it would have otherwise. Am I out of my mind to think that there's a correlation between those things? Or do you? What do you think? And I know you're a doctor and we need randomized, controlled, blind. I get all that, but just what do you think?

Dr. Kevin Tracy (45:47)

Well, I think that this could be the topic of another four hour show. That's the simple answer. It's complicated because it goes both ways at the end of the day. That's the simple answer. What happens in your brain affects what happens in your body. What happens in your body affects what happens in your brain. So tuck that away as the answer. But the second answer is it's genes and environment, it's nature and nurture and you can't separate those. So you. Let's do that one first. So two guys are playing golf and they get hit by lightning, they both get killed. Is that genes or environment? You tell me. Well, it's environment, right? Then I tell you it's a father son combination. And they play golf and Friday every weekend in the summer when the, the, when the lightning comes out. So now it's genes and environment, right? So the same, the same kind of logic can be applied to everything you just said happened to your dad. So let's just, we'll play it backwards and forwards. Let's talk about the anxiety and the, the worry first. So obviously it's possible that as they as, as people like to say, there's an imbalance of neurotransmitters in the brain that contributing to him having annoying depression or annoying anxiety. Well, it's possible, but there's no proof of that. The most commonly, the most commonly used antidepressants in the world, the SSRIs, the serotonin based drugs, there's zero evidence linking serotonin as a causative factor. In depression, zero. The only evidence for serotonin that has stood this test of time is a secondary evidence. Meaning that some people who take SSRIs have less depression. That doesn't prove cause and effect. Because SSRIs do other things in the body. They don't just go to the neurons in your brain that allegedly have a serotonin problem. Okay, so we don't understand that. We don't understand depression. That's the point. However, we do know that SSRIs in. In various conditions, they've been studied, are anti inflammatory. So now what about this scenario for your. Your dad. Your poor dad lived his whole life. Maybe induced by. By drinking a extra pint or two along the way, or maybe because he had an underlying viral infection, but deep in his tissues he had inflammation. And I already talked about it. The inflammation in the body sends signals up the vagus nerve which cause depression. What if that happened to him? That's very possible. And maybe that depression altered the balance of his sympathetic and parasympathetic nervous system. So maybe he did have less. Less breaks on his inflammatory response. And maybe that inflammation, either from the underlying cause, which we don't know what it was and never got diagnosed, or from the uncontrolled inflammation that he experienced as a result of his depression, maybe, maybe that caused his cancer. So I'm not evading your question. I am adding a layer of understanding that it's more complicated than these one off things that you see so many times on these self help pages. Look, I've met people with serious rheumatoid arthritis, and I keep talking about that because that's what the FDA label says for the new device. I've met people with serious rheumatoid arthritis who are fit, who are healthy, who work out like you do, are very aggressive and careful about what they eat and about their weight management and about their meditation strategies, and they still have severe rheumatoid arthritis. Is that their fault that they're not exercising and. No, of course not. It might be that their vagus nerve circuits are dysfunctional, that they are broken. And that could have been the case in your dad. He may have had a perfectly healthy brain, but maybe his vagus nerve got trashed along the way. And. And we saw that in Covid. I don't know if you saw this, but in Covid victims were studied at autopsy in. In. I believe it was in Madrid, Spain. I mean, this got huge news coverage when it came out. But their vagus. Many of the vagus Nerves in the deceased were severely injured and many of the vagus nerves in the deceased had the virus in the nerve. And so then, since then, a number of studies have looked using fmris and ultrasound imaging at Covid survivors who had long haul Covid or have long haul Covid and they show evidence of damage in their vagus nerve. So now the question is, does the vagus nerve damage precede the inflammation which precedes the problems in the cancer? So I don't have all the answers, but those are the right questions.

Ed Mylett (50:40)

I love when I have a doctor on the show who doesn't think he has all the answers. And I've been concerned over the last eight or 10 years when I have them on and they have every answer because now they don't have any curiosity and they're dogmatic. And so I really appreciate your approach. Is there any practice every day, by the way? And you can reply to that. Is there a practice every day? Like you just won't skip as you answer what I just said too? I mean, please don't, don't feel obligated to do that first, but go ahead and reply to that. And then also like, is there something daily, like, hey, this is something every day I do, period.

Dr. Kevin Tracy (51:17)

Well, I, I really appreciate your, your, your comments on dogma. And there, there is a danger in medicine and science and, and frankly, you know, whether you agree with what's going on everywhere in politics today or don't most people have one position or the other, there is obvious to me there is a pushback now against academic dogma as providing all the answers all the time. And some of those reasons are not warranted, but some of them actually are. And I think it's really important when we don't have all the answers that we say this is what we know for sure, this is what we are pretty sure is false, and this is what we should be studying. And as you know, I wrote the book. One of the reasons I wrote the book was to sort of have that be a message of hope and a call to action. You really, I really want my colleagues to double down on some of these questions that you've raised in this podcast, because if we double down on what the questions are, then we can figure out how to find out new answers. And that's what, that's what we want, right? That's what everybody wants. You asked about my daily habits. I mean, yes, I do. What, what grandma said and what, you know, your doctor and what you, you say on the show. I try to watch What I eat, I try to eat a balanced diet. It's difficult to eat a balanced diet. I frankly find it easier to just avoid carbs and eat and eat protein where I can get it and as many vegetables as I can. I try to exercise regularly. I try to get in some different forms of exercise, some, some aerobic, some yoga or stretching and, or stretching and some, some strength and isometric. I think all those are important. I think Peter Attia's written, written brilliantly about this and, and I think he gives very sage, careful advice for people of all ages. I try to get enough rest. I definitely try to get my seven or eight hours sleep. I think that's really important. I don't monitor by rest with a, with a wearable because I, every person I've ever met who uses a wearable to monitor their sleep wakes up to check their wearable.

Ed Mylett (53:28)

Exactly right. By the way, it's also the first thing I do when I wake up, then I pray, but it's not until I check my aura ring, which is insane.

Dr. Kevin Tracy (53:37)

So I try to, I try to avoid too much stress in my life, try to take a stoic approach and focus on the things that I can control and you know, accept the things that I can't control. And I try to stay socially engaged with, with people that, that I love and communities I care about and I try to give back to the world. I mean the classic things that as I said, grandma, and hopefully your, your primary care physician is, is teaching everybody else to do. It's interesting to me that all of those things tend to slow your heart rate, you know, and so maybe, maybe, maybe we're slowing inflammation in the body. And at that point it really is a pascal's wager for do the cold showers too. We talked about that. And I don't mind doing those things. They might be good for me if I'm on my deathbed and I find out that it was no use whatsoever. Well, you know, I did my best and, and if I live to be 120 and I'm healthy, well, that'll be good too.

Ed Mylett (54:34)

You know, I look at it like, by the way, I'm teaching myself to do hard things. At a minimum, I'm getting that benefit of building some grit. And if there's some internal benefit, which my hallucination is, there probably is, then that's a bonus. But I'm doing difficult things.

Dr. Kevin Tracy (54:48)

There's pretty good evidence for parts of the brain that light up on brain scans. Only when you do something you don't want to do that's good for you. And so that strengthening of grit is being studied at the level of brain neurons. And that's interesting, too, and I agree with you. For me, it's stepping in that stupid cold shower.

Ed Mylett (55:10)

Same here, brother. That's mine. And I don't like it. And I've never adapted to it. So. By the way, guys, I don't want to lose this idea when you're getting the book. I mean, just so you know, the book is fascinating and just realize, like, I don't want to bury the lead. I mean, he was a founder of a company that just recently is now putting chips inside of people that is stimulating the vagus nerve. And the potential for what that could mean for inflammation in the body and the reduction of disease potentially in the world is absolutely, absolutely. It's massive. And you all hear about this AI revolution that's happening. This is one of the applications and implications of it. And I want to make sure the lead isn't buried, that this is. This is a time. This man, earlier in the show, now that you've heard him, this is not a dogmatic, opinionated person, you know, just rigid in his ideology. He said earlier in the show that he thinks the potential for electricity in the body and the stimulation of it to replace or at least reduce the need for pharmaceuticals. That's a pretty bold statement, and it's a significant time we're going to be living through. So I want to ask you one last question, because I teased it earlier and I at least want to have it there for conversation, which is this idea of heart and brain coherence. I just want you to. We'll finish with that, and then I'll. I'll talk about the book for a second when we finish. But what is that? Dispenza talks about it, my buddy who's been on many times. And what are the implications and why is it relevant, in your opinion, if at all?

Dr. Kevin Tracy (56:43)

It's relevant in the context of larger picture of health, which is homeostasis. So what is homeostasis? Homeostasis is a balanced functioning of your organs. So your kidneys are making the right amount of urine, your heart's beating at the right pace to support your blood pressure. Your blood pressure is not too high, not too low. Homeostasis is when all of your organs are operating in a Goldilocks, not too much, not too little kind of output that is all controlled second to second, millisecond by millisecond, actually, by reflex signals traveling in mostly in your vagus. Nerve and in your sympathetic nerves. So if you think about that for a minute, it's kind of mind boggling. I mean, you can separate in various experimental models and even in some pharmacological ones, you can separate the function of sort of your thinking human brain from the brain that's operating all day long to control these reflexes. And when you look at the output of those organs, the beauty of it is that it's not railroad ties, boom, boom, boom, boom, boom. It's waves. So the, the harmony between the organs. If you were to measure each organ as having its own output and you do that electrically, what you see looks like a symphony, not banging a gong. In fact, if you see a banging gong, and I can, and I can direct you to a place where you could see it this afternoon, it would be in the ICU of a hospital. So when people are critically ill, say they've had sepsis for a long period of time and they're the, and, and they're very, very sick, that their heart, their heart rate, their heart rate doesn't vary. It's beat, beat, beat, beat. And the outputs of the other organs doesn't vary. It beats with the heartbeat. Everything's in lockstep. It's almost, it's the opposite of a symphony, of a symphony. It's a banging of a gong. And so I don't think we fully understand what that means, but it points to the importance of synchronization, of harmony between not only the brain and the heart, but the brain and every other organ. And the heart's fun to measure because you can check your pulse and you can do an EKG and you can check your blood pressure, you can experiment on yourself and it's great. But when you apply the same basic teachings to the other organs, it's fascinating. So we're in my lab now. It's the hottest project in my lab now, which we got a whole bunch of people working on it. And we're actually studying the flow of information that's going from the organs in the body up the vagus nerve into the brain. And we're hacking into the vagus nerve signals like submariners would hack into a transatlantic cable so they could watch a movie on the wall of the submarine. By tapping into the cable, we're learning how to tap into the vagus nerve to understand what these signals mean and how they work. But the harmony, the harmony is the key. Harmony is the key thing people call the vagus nerve superhighway. It's not, it's not I never. I never use that description. A traffic. Traffic is boring. And the signals in. In the. In the vagus nerve are much more beautiful and. And. And. And harmonious. They're like the. They're like the strings of 30 violins all sort of playing in harmony. And that's what health is, you guys.

Ed Mylett (60:22)

This is such a. A great time to be alive, and we may all have a chance of living a lot healthier and a lot longer here real soon. By the way, that lab, is it Feinstein or Feinstein?

Dr. Kevin Tracy (60:36)

Feinstein Institutes at Northwell Health.

Ed Mylett (60:39)

There you go, you guys. And the book everybody is for the fifth time, is the Great Nerve by Dr. Kevin Tracy. And I think you could tell today there's a lot in this book. There's no wasted pages. Every page is interesting. You're going to learn something, and I know you did today. Guys. You guys want to have them back on? I can hear you yelling in your car right now. Yes, they're on their treadmills yelling. So we're gonna have you back. We'll. We'll take a little breather for a while, but we're gonna have you back and unpack a bunch more stuff together, okay?

Dr. Kevin Tracy (61:05)

I look forward to that. And I want to thank you for your preparation and your insights to this. This has been a real pleasure talking to you and thank you for having me.

Ed Mylett (61:13)

On my honor, brother. All right, God bless you, everybody. Share this episode. You need to share this one. Max out your life. Take care.

Dr. Kevin Tracy (61:23)

This is the Ed Milan Show.

Podcast Host/Announcer (61:38)

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Ed Mylett (62:07)

Com.