32 Ways to Stimulate Your Vagus Nerve, Fine-Tune Your Nervous System & Self-Hack Your Hormones.

In this episode of the Ben Greenfield.

Fitness show, what makes it relaxing for the brain? By decreasing the HPA axis, decreasing the autonomic, fight or flight nervous system. When you decrease that system, that has a very potent effect on the brain. As far as the hypothalamus, the suprachiasmatic nucleus does connect to the brain stem and that connects to the rest of the body. Each of the cascade in the thyroid hormones, so this TRH, TSH, T4 and T3, those are usually associated with weight loss, but they do increase appetite. So the thyroid, thyroid hormones do increase appetite because they're stimulating metabolism even more.

He's an expert in human performance and nutrition, voted America's top personal trainer and one of the globe's most influential people in health and fitness. His show provides you with everything you need to optimize physical and mental performance. He is Ben Greenfield. Power, speed, mobility, balance, whatever it is for you, that's the natural movement. Get out there. When you look at all the studies done, studies that have shown the greatest efficacy, all the information you need in one place right here, right now on the Ben Greenfield Fitness Podcast. Hey, folks, it's Ben Green Field. And when it comes to your hormone balance, your sleep, your mood, your gut function, your physical performance, your cognitive power, pretty much every body and brain variable you'd ever want to optimize, there's something that I think is more important or at least way underplayed compared to your heart or your brain or your lungs. In my opinion, a huge part of fixing everything I just talked about or optimizing everything I just talked about comes down to the health of something called your vagus nerve. Now in podcast number 31, which I'll link to in the show, Notes to this podcast, which you can find@BenGreenfieldFitness.com Vegas that's BenGreenfieldFitness.com not the city Vegas, but the spelling is V A G U S. In that podcast, I talked about your vagus nerve enhancing vagus nerve tone, kind of hacking your nervous system. But honestly, I, I pretty much scratched the surface of everything that you can do to care for and enhance this nerve. Because when you can get this thing taken care of, you'll be pretty shocked at the results on things like stress and heart rate variability and mental horsepower and physical performance recovery, digestion, libido, you name it. I wanted to get a guy on the show who is an expert in biohacking your body, upgrading your body, and also somebody who knows quite a bit about the vagus nerve and his name is Joe Cohen. Joe's the owner and author at a website called selfhacked.com, which is a great site. It's got a really good link to the vagus nerve that I will link to in the show notes to this episode. But Joe has upgraded and biohacked himself and also he's now an investor and an entrepreneur. He founded a company, a biotech company called Self Decode. And he helps people understand their genetics in order to optimize their health, using things like genetic testing and blood testing and health data to kind of design drugs and supplements and lifestyle and dietary changes to optimize health. So he works with high profile execs and self hackers and companies and he's even writing a book right now in all that free time that he has. Joe, I understand that you like to program or code computers, is that correct?

Well, kind of. I'm pretty much a newbie. I started because when I found my company, we first called it something else. But I was working with developers, I was trying really hard to get a good developer and I realized that that was the blockage for getting a really great company. And if you wanted a good developer, it was going to cost like hundreds of thousands of dollars. Finally I found a great developer. We rebuilt the whole program from scratch and it's going really, really well. But even so, it's just something that you can automate so many things if you know programming. So it's something that I feel has a good roi.

Yeah, it's tough man. It's like learning a new language. I took coding in college and then taught myself HTML and JavaScript back when I was designing all my own websites. And dude, I don't think I'd go back and do it again now that we live in the era of freelancing. But I think for you, I mean like in the position you're in with this whole idea of self decode and decoding the human body, it's kind of cool that you're learning to understand code. I recently read a really good book about code and how DNA is code. It was by this guy named Perry Marshall. I think it was Darwin and design. He go, he basically goes into how our entire DNA and genetics setup is computer code. Have you come across this?

No, I have not. Have not read the book now.

Yeah, it's by Perry Marshall. You'll have to check it out and I'll put links in the show notes by the way, for those of you who want to. But I had heard of Perry because He was like big into Google, AdWords and PPC and online marketing. And I'd met him at conferences and stuff. And then I see this, this book comes out that he wrote on DNA and code. Kind of, kind of a weird book to see a guy like that write. But anyways, I digress. You have written, I've seen before on your website, in your bio that you considered yourself at one point to be completely unemployable. What do you mean by that?

Well, okay, so I'll give you some backdrop here. I grew up in a, you know, a culture which didn't value education very much. They valued, like, I grew up in Orthodox Jewish culture. So in the Orthodox ultra Orthodox Jewish culture, they valued more religious teachings. And for me, my family wasn't like too religious within that culture. So I didn't really, I didn't really have any interest in the religious teachings, nor did I get any education. That in combination with, you know, just a bunch of health problems, nothing like serious, you know, no like diagnosable disease, but just a whole bunch of a long list of like fatigue, you know, arthritis when I'm like, you know, 18, just like chronic inflammatory issues, but nothing so severe that is like, okay, you've got this disease. You know, to me it was normal. It's kind of like, yeah, I got brain fog half the day, tired. And then I also didn't really have a great education, so I was disadvantaged in quite a few ways. And, you know, things were getting a bit better. But then when I turned 25, things just took a dive for the worse. And, yeah, and my health just collapsed. And I was just like, all right, something's not right here. I gotta figure this out. And, you know, I thought I was a smart guy, but, you know, my brain never worked. And it was just, I realized I was like, listen, we're living in a time where if I'm not intelligent, if I can't use my brain, if I can't perform, I'm done. As time progresses, technology is getting. We're living in an information age. And how capable you are with your brain is basically how successful. It plays a very important role in success.

Absolutely. You kind of sound like a Brooklyn version of Dave Asprey in a way.

Kind of. Kind of, yeah. But for me, yeah, I mean, I didn't start. I mean, he's a high tech executive. I guess for me, I started out as just not any kind of executive or anything. I barely worked because I wasn't, you know, very capable. And I just, you know, then I just said, that's it, I'm figuring this out. I just tried everything, every substance, every diet. I was already trying some things before for a while. I was into health for a while, but I just went gung ho and I said that's it. You know, at some point I started self hacked when I made some breakthroughs to share them. And then as self hacked went on, I got better and better, you know, and I'd say two years ago I was pretty much pretty good. Even though I've made some incremental improvements since then. But you know, I spent a while just, you know, just, I didn't go out, I didn't do anything. I just said, I'm going to figure out this body from top to bottom, all the nuts and bolts of it. And then, you know, how did you do that?

Were you, were you using like for your research? Because I've seen your articles and they're really good, you know, a lot about the human body and obviously we're going to delve into a very important part of this in a little bit. But how did you learn all this? Like because, because if you didn't go to, you know, university and people, people are going to ask that question. I know too, on the podcast as we're talking is, is, you know, are you like a Google Scholar PubMed guy? Are you like the library over there in Brooklyn or what's your go to?

Well, okay, so I did have some, you know, education but that stuff didn't actually help me that much. The science education was just pre med because I figured, you know, I'm unhealthy, I need to figure this out. I might as well work in something that, you know, allows me to figure it out and help other people. So I did have like the pre medical coursework which gives you a good basics, not that I needed it. If I would have used that time for just researching myself, I would have known a lot more, a lot faster. But it was useful, it wasn't like a complete waste of time or anything. But anyway, yeah, so what, I mean all I did was just, I was, I just read like tens of thousands of PubMed articles really, that's it. And I would just search. I became a Google Scholar like, but everything I searched for was just like pubmed after I never read anybody like, you know, a lot of people have decent content but it's, it's not like technical. You're not going to make, you know, you're not going to break ground. Yeah, I mean going straight to the studies really allows you to see the nuts and bolts of what's going on.

It does. If you, if you know how to read studies, you know, that's one of the things. There's actually a really good research review. And for those of you listening in, I promise we'll get to the vagus nerve here in a second. There's a guy named Alan Argon who puts out this thing called a research review that I subscribe to. And it's mostly reviews of fitness and nutrition and health research. But he also has quite a bit in there, especially in the back archives, about how to read studies. And if you want to know how to read studies, in my opinion that's a really good go to resource. If you don't want to take a stats class, I'll link to that in the show. Notes for folks. But it sounds to me, Joe, like, like you're an independent learner. I mean, I was homeschooled K through 12 and my mom used to shove books under the door and I'd read them and that would be my education. Do you. Are you one of those guys who just like pick something up and learns it kind of like coding?

Yeah, I am one of those guys. Just an independent learner. But in the beginning it was very tough. I mean, I was having like brain fog and I was like not understanding most of what I was reading. I was like, I'm just reading this anyway. And then after it's. It's really a language. Picking up the language. It's like coding. It's a new language. And if you learn the language, things get a lot easier.

Yeah. And I'm sure that the pre med background helped out nicely. Yeah, I did that myself. And that puts anything in context when you've had microbiology and biochem and organic chem and physics and everything else you have to take as a, as a pre med. Well, let's jump into the vagus nerve, man. First of all, the obvious question here is what exactly is the vagus nerve?

Vagus literally means wandering, right. That'll give you some idea of what it is. It's just this nerve that's connected to the brain stem. You know, it's the part of the brainstem is called the nucleus tractus solitarius, the nts. But it's connected to the brain stem and it goes to basically every major organ and all the major parts of your body. So your pancreas, your liver, your gut. And that's where the main, you know, that's a lot of the effects the Mind, body, connection. So, you know, if you're stressed or whatever it is or things that happen in your gut, it works its way to the brain. 80% of the signals go from the periphery, so the organs to the brain, and 20% of the signals will go from the brain to various other places.

Okay, gotcha. So. So in terms of the vagus nerve and just like how, how a nerve works in general, because you talk or you hear a lot of people say, like if the vagus nerve isn't working properly, if you have a low vagal tone, for example, it gives you gut problems, which is obvious. If it wanders through your body and goes through every organ, including the gut, it gives you brain fog, obviously, because the, the message goes both ways. Right. If your gut is. Is inflamed or vagus nerve is. Is affected farther down, it would affect the higher order up in the brain. Right?

Yeah, but I don't think the vagus nerve itself is causing brain fog. I mean, brain fog is. And you know, I spoke to Dr. Jared Younger. He would say like fatigue, right? Brain fog, fatigue. These often go together. These are general alarm signals in the body. Something's not working. Well, usually these general alarm signals come from inflammation or oxidative stress. So the vagus nerve can be connected to that in some way. I'll get to it. But pretty much, if you've got anything that is causing inflammation in your body, you can have more fatigue or more brain fog. Inflammation will cause oxidative stress, and the hypothalamus can sense these things in the body and says, things aren't right, let's rest and go to sleep. So brain fog and fatigue are general signals that can be from anything that causes inflammation or oxidative stress. Now, I spent a long time trying to figure out what those things were. I have a framework that I use, top eight things that cause inflammation, oxidative stress that will lead to these things. But yeah, general signals. Now where the vagus nerve comes in is the vagus nerve releases acetylcholine. It activates the cholinergic pathway, which is a very.

Yeah, that's what I wanted to ask you actually is like how. So people can understand how the vagus nerve actually works.

Yeah.

So how a nerve works, really.

Right. So a nerve will, you know, same way in the brain, a nerve will fire and then it releases neurotransmitters. So same way with the organs, it'll fire and it will release neurotransmitters to the organs and, you know, and do things and so the main one, there's a few things that it can release. It can release nitric oxide, which is more inhibitory, but it can also release. The one that is anti inflammatory is acetylcholine. And so that acetylcholine will activate the cholinergic anti inflammatory pathway. And I take things that activate that pathway regardless of the vagus nerve per se. So things like Huperzine A would activate the cholinergic pathway by increasing acetylcholine. It inhibits that enzyme Huperzine.

That's like a derivative of Club moss, right?

Exactly, yeah. So by inhibiting an enzyme that breaks acetylcholine down, it increases acetylcholine. Then you've got galantamine, which is probably my favorite. And I started taking galantamine on the recommendation of Lost Falco, but that was a good one.

Galanthamine sounds like a giant from the Bible. How are you spelling that?

Well, actually the interesting thing is I took it literally like eight years ago or. No, yeah, it was like seven years ago. I was on this binge of like it was a minor binge earlier and I took galantamine. I didn't really. I was taking a whole bunch of things. I didn't notice anything. Cause I wasn't able to see what was doing what. But later on now I just try one thing at a time.

Are you talking about the actual prescription drug Galantamine? That one, yeah.

So galantamine is the prescription drug and it's also from herbs. So you're allowed to sell it on the market because it's like from plants, but they also use it as a drug.

So one could get it on like Amazon or via prescription from the doctor.

That's right.

Interesting. Well, I don't want to delve too deeply into supplements yet until we finish talking a little bit about how the vagus nerve works. So let's look at how the vagus nerve actually influences different organs. So people can kind of understand the interaction between the vagus nerve and their overall health. So for example, the brain is obviously the biggie. What would we be looking at in the brain as far as what the vagus nerve could do?

It'll cause relaxation. Okay, that's something that.

Do you specifically know how when someone gets. For example, I will do jaw realignment, for example, to adjust my. Really it's my trigeminal nerve which affects my vagus nerve, which causes. And I've tested my heart rate variability on this. A big increase in parasympathetic nervous system activity or that increase in the rest and digest energy system. But is there a specific neurotransmitter that gets released by the vagus nerve or some kind of inhibitory signal that's caused by the vagus nerve? When I say stimulate it via something like a jaw realignment massage?

I'm not sure about that one per se. I do know that the trigeminal nerve does connect to your nervous system. Exactly how it connects to the vagus nerve, I'm not sure.

Okay. But basically in the brain, we're talking about people who are overexcitable. Somehow fixing the vagus nerve in the way that we're about to talk about it can help control overexcitability.

Yeah. So, you know, actually, so let's say one way would be like oxytocin. So, you know, releasing oxytocin in the brain, that's calming. That's one mechanism.

So does the vagus nerve itself actually release hormones or cause the release of hormones?

Both, actually.

Interesting.

Yeah. There's hormones that it releases, and there's hormones that, if you activate that, cause the vagus nerve to activate.

Okay, got it. So moving on past the brain in terms of other organs that the vagus nerve actually interacts with, Obviously the gut is a big. You mentioned the gut, but what does it actually do for the gut?

Okay, so that actually does a lot of things. So one of the things it does is release histamine. And histamine is important for gut flow. So basically it'll increase the gut flow. So that's why something like gastroparesis, which is things stay there, it increases the flow of gut. It's called motility is the technical term. And let's see what else it does with your gut. Just digestive juices, stomach acidity. So things that are involved with digestion, IBS, C, which is like constipation, will often be caused by less activation. You know, things are going slower.

Okay, got it, got it. So in terms of the gut, would that include things like the spleen, the pancreas and liver, or does it act upon those in a different way? Or does the gut. It's going to cover all that?

No, it does different things for different organs. So for the gut, one more thing would be to release intrinsic factor which helps you absorb B12. But the things I just mentioned for the gut are just for the gut. Okay, then for the spleen, it will, let's say, inhibit inflammation. Again, the spleen is an important part of your immune system. So based on the organ and its functions, it Will do things related to that organization.

Okay, gotcha.

Yeah.

So in terms of like reducing inflammation, are we talking about it like releasing anti inflammatory compounds? Does it release some kind of like anti inflammatory neurotransmitter or how does that work?

Yeah, so the main thing that it does is release acetylcholine which is the anti inflammatory, which activates the cholinergic anti inflammatory pathway. And it'll do this in a bunch of different organs. Yeah, so whatever.

That's interesting. It makes me think. Sorry to interrupt about, you know, Wim Hof, the iceman who they tested to be able to consciously reduce his cytokine levels. I know that a lot of what he's doing, like breath holding cold water, immersion, yoga, meditation, things like that, all of those can be vagal nerve stimulants. And it's possible that he's getting a big acetylcholine dump into his spleen to reduce some of these cytokines and inflammatory factors.

Exactly. Yeah. There was a study that he conducted that showed that various neurotransmitters went down. Not neurotransmitters, cytokine. Sorry. So yeah, that could definitely be. Have to do with lowering inflammation in the spleen. You know, like lowering the activation of the spleen and lowering inflammation in general.

And you also talk about how the vagus nerve. You wrote this in an article about how it affects the bladder and also the sex organs. I thought what it does to each of those was pretty fascinating. Can you go into that?

Yeah. So let's say for the sex organs it's more for women. For women it will help women, let's say orgasm. It has some role in fertility. And as far as let's say the bladder, one effect of vagal nerve stimulation, like a side effect is urinary retention. I used to have, I used to pee all the time. Could have been from low vagal stimulation.

So what about when you talk about how it affects orgasms in women? Is it true that if you somehow stimulate the vagus nerve in like some other area of the body that it can, it can cause a woman to have an orgasm?

Yeah. So the vagus nerve is connected all over the place. So if you stimulate it in one place, it could stimulate it in another. And so yeah, it's, you know, if you, if you make a girl laugh, it could stimulate her in other places.

Interesting. Yeah, I've heard about that before, but I hadn't really realized that it actually comes down to the vagus nerve. It's super interesting. I mean there's so many areas of health that it actually affects and obviously so many conditions that it could assist with. I wanted to ask you a couple of other questions, though, before we jump into how to hack it. First of all, hormones. We talked about how it can release acetylcholine or cause a release of acetylcholine, which would shut down inflammation. What are some other hormones that interact with the vagus nerve?

Okay, so as far as the hormones, I'll go through some of the hormones that can increase vagal activity and some that are increased by vagal activity. So let's see. Let's go to the hormones that activate the vagus nerve, and they activate it in more local ways. It's not necessarily systemic. It can be, but not necessarily. So let's say insulin, thyroid hormones, and ghrelin can stimulate the vagus nerve. So ghrelin, everybody. You know, most people know what thyroid hormones are. Insulin, ghrelin is the hunger hormone.

Okay.

And the way that increases hunger is in part by stimulating the vagus nerve.

Okay, gotcha. So basically, we would see an increase in ghrelin, but so are you saying that if people have strengthened their vagus nerve, they're gonna get hungrier?

Theoretically, that could happen, but that would.

Basically not be because it was a hunger that would be causing them to become fat. It would be a hunger because of this increase of a normal appetite hormone. And is there an effect on the thyroid as well?

Well, the thyroid hormones increase appetite by activating the vagus nerve.

Okay, and then that increases ghrelin.

Yes. Well, it doesn't increase ghrelin. Thyroid hormones and ghrelin, in part, mediate increasing appetite through the vagus nerve.

Okay, so essentially, if you're increasing your vagal nerve tone, you might experience an increase in appetite accompanied by an increase in thyroid hormone and overall metabolism.

Well, the thyroid hormones will increase the vagus nerve. The vagus nerve doesn't increase thyroid hormones.

Okay, so.

So it doesn't go the reverse.

Okay, so what you're saying is if you fix your appetite signals and you fix something like thyroid, that. That would affect the vagus nerve.

Yeah, but it doesn't mean you'll gain weight.

Right. Because I know a lot of people are gonna be concerned about that. They'll be like, oh, I fixed my vagus nerve and get fat, thank you very much.

Right, exactly. That's not a good thing to conclude, because thyroid hormones also increase metabolism. So you might eat a little more, but you'll also burn more. Ghrelin actually also increases metabolism. So same you might eat a little more, but you'll burn more. So actually, thyroid hormones are more associated with weight loss and each of the cascade in the thyroid hormones. So there's TRH, TSH, T4 and T3. Those are usually associated with weight loss, but they do increase appetite. Right, so the thyroid hormones do increase appetite, but they're associated more likely with weight loss because they're stimulating metabolism even more. There is conflicting studies with ghrelin, but overall studies don't show that ghrelin will increase weight gain. I wouldn't worry about that.

Yeah. All right, that makes sense. What are other hormones? What about testosterone? Can it affect testosterone?

Right, so now here's the other side of the equation. What does the vagus nerve release? We just discussed what causes the release of the vagus nerve. You know, what activates the vagus nerve. Now we can. Now what does the vagus nerve cause to release? So I mentioned oxytocin. Oxytocin, you know, is that calming social bonding hormone. It releases. It can release testosterone, you know, and again, testosterone is kind of an aggressive hormone, but if it's, you know, if the vagus nerve is releasing it, it also has that calming effect from activating the vagus. The vagus nerve can also increase growth hormone releasing hormone, which is that hormone that's important for sleep, and releasing growth hormone, of course, and IGF1. So it releases GHRH and IGF1, and it also increases parathyroid hormones and VIP.

Okay, so growth hormone releasing hormone is the GHRH, and then IGF1 is an insulin like growth factor.

Yes.

Okay, so basically like an anabolic type of effect.

Mm, sure.

Interesting. Okay.

Yeah. And then VIP is a very important anti inflammatory hormone. A lot of people with, like, chronic inflammatory issues can often have lower vip.

And that's the vasoactive intestinal peptide one.

Exactly.

Okay, gotcha. So there's a ton of hormones that the vagus nerve interacts with. There's a ton of organs and body systems that it interact. I know there's a couple of other things that are important about it. Circadian rhythm is dependent on the vagus nerve, right?

Yes. So the vagus nerve connects to the brainstem and the brain stem connects to the hypothalamus. So in the hypothalamus, you have the center of the circadian rhythm, the suprachiasmatic nucleus. And the hypothalamus is obviously the start of the HPA axis, hypothalamus, pituitary adrenaline. And so vagus nerve stimulation decreases that axis so you know what makes it relaxing for the brain? By decreasing the HPA axis, decreasing the autonomic, the fight or flight nervous system. When you decrease that system, that has a very potent effect on the brain. But yeah, as far as the hypothalamus, the suprachiasmatic nucleus does connect to the brain stem and that connects to the rest of the body.

Okay. So basically that might be a reason why when I get jaw realignment therapy and it affects my trigeminal nerve, which I know interacts with the vagus nerve, that it would potentially help me to sleep better if I'm increasing my vagal nerve. It actually helps with the signal to the circadian rhythm.

Sure, yeah. And then it could also be because if you're increasing the vagus activation, then you'll also increase ghrh, which is important for slow wave sleep.

Okay, gotcha. So in terms of messing up the vagus nerve or causing it to not be optimized in the first place, how would that actually happen? How would someone lose vagal nerve tone or what are main ways that we could actually basically mess up the vagus nerve?

So I'd say one way, I mean, you can look at it in terms of we've evolved to have a lot of. We've evolved in a certain way and not doing certain things can increase vagus activation. So for example, we've evolved to be more social, be cold sometimes. Right. Right now we have temperature regulation at all times. And so having positive social relationships, these things. And let's say our lifestyle is like chronic stress. Right? So over time that can put pressure, meaning, like, it's not enough if you're very stressed all the time, it can over time, let's say, cause lower vagal activation.

Okay, gotcha. But in terms of, like, how the, how the vagus nerve actually works, like, in terms of like, the way it can be stimulated or the way that it could potentially be inhibited in the way that interacts with the brain? Specifically, is it that we damage the brain and the vagus nerve becomes affected via that, like head injuries? Would it be like, loss of neurotransmitters, like communication within the brain? Would it be some type of nerve dysfunction affecting the brain's ability to stimulate the vagus nerve? I mean, what exactly is going on when it's not working properly from a biochemical or a biological standpoint?

The truth is, I don't know the exact answer to that, but there's some possibilities. I mean, you know, let's say if you have oxidative stress in the hypothalamus. The signals, you know, might not be going back and forth. If you're disrupting your circadian rhythm all the time, it might cause issues. If you're chronically stressed, it can cause some issues. So I don't know the exact answer, but I would say, if I had to take a guess, I would say that, you know, something scrambling the signal. Yeah, it's probably something like that.

Got it. Well, let's have some fun now. Let's talk about what we can do to actually fix our vagus nerve or to, you know, to hack our vagal nerve tone. In terms of free things that one could do. Just like cheap, free, easy to access, not expensive supplements, but just like basic things people could do to stimulate the health of their vagus nerve. What would be a few of your favorite examples?

So let's say a common one would be like, let's say meditation. It was found that meditation is capable of increasing vagal tone, especially loving kindness meditation.

What is loving kindness meditation?

It's kind of like I don't really do this myself, but my understanding of it is you just have these, you know, you think about like compassion, you think about compassionate things like, you know, I love the world or I love this person, or, you know, you think about a certain person and you'll be like, you know, like just, you know, just have compassion.

It sounds a little bit like, like the quick coherence technique, like the heart math quick coherence technique, where you're thinking something about gratitude and then imagining that, that feeling going into your heart. Sounds very much like that.

Yeah, that would be like a variation of it. Sure. So I think there's a whole bunch of variations of it. That would be one.

Okay, got it. So something like loving kindness meditation, that's obviously free. We mentioned cold water, right. How you can jump into cold water or splash it in your face. And by the way, I was actually going to ask you about cold water. What about like cooling gear? Like, you know, people like make these vests that have ice in them and stuff like that. What are your thoughts on or have you looked much into those and the influence of cooling gear on vagus nerve function.

So there's no studies on cooling gear specifically. I would say maybe I use it sometimes. But the main thing is you want to. What will do it is like an acute cold exposure. Cold gear might not be cold enough. It could, I'm not sure. One way or another I do it and you know, but what I'd say is, you Know your vagus nerve is activating when you take a cold shower and you feel like this stress response. And then after you get out, you feel very relaxed. That's the vagus nerve.

Okay, got it, Got it. Yeah. Because these. These cooling gears, they don't give you that intense initial almost like shock that I seem to get when I dip my face in cold water or I jump into cold water. So I'm just curious how much vagus nerve stimulation is happening from something like that. But it sounds like they've never really been studied, huh?

No, probably not that much. If you wanted to be more safe about it, I would just go dip in cold shower, cold lake, whatever.

Yeah. Now, what about. So we've got cold, we've got meditation. What would be one more example of something free and easy that one could do?

Breathing, and I'll give you another one, is positive social relationships. So, you know, let's say breathing number one would be they found, like, breathing in and out five times, five breaths per minute can be helpful. Slow breathing with equal time breathing in and out.

It's like box breathing, basically.

Yeah, yeah. So that's pretty much what I would suggest with the breathing. You know, then there's positive social relationships and just kind of, you know, just being in, like, a positive state. Positive emotions. Like, for example, I'll give you a study where participants were instructed to think. To sit and think compassionate, compassionately about others by silently repeating the phrases like, may you feel safe, may you feel happy, may you feel healthy, may you live with ease. I mean, these are just generally having, like, a positive vibe, right? And. Yeah, so it's just like a general positive vibe. Greater sense of connectedness with others, These kinds of things, you know, being, being in love, positive social relationships. These kinds of things can help with the vagus nerve.

Got it. Now, what about. What about foods? Do certain foods seem to affect the vagus nerve?

I think, let's say. So let's say fish, right? That's because the EPA and dha. So EPA and DHA is known to increase heart rate variability and lower your heart rate. So eating a lot of fish is one thing. And let's say fiber. Fiber increases GLP1.

And GLP1 is what again?

It's a satiating hormone released by the gut.

Okay, gotcha.

That can stimulate the vagus nerve impulses to the brain. So, yeah, like, let's say there's, you know, resistant starches of fiber. There's a whole bunch of soluble and insoluble fibers that you can eat. But you know, just fruits and vegetables.

Okay, well, what about just like eating strategies in general? I mean, is it regular eating? Is it frequent grazing and snacking, intermittent fasting? Like, is there some eating strategy that seems to do best when it comes to maintaining vagal nerve tone?

Okay, yeah. So fasting can increase vagal nerve tone. So fasting is a good one. Cck, which is activated by like fat or a variety of different foods. Let's say potatoes. So CCK can activate vagal impulses. For me, I don't, you know, I don't eat potatoes and stuff or, you know, grains. But if you do fine with it, then sure. But yeah, fasting is a good one.

Okay, gotcha. So we've got different lifestyle strategies, different food or food strategies like fish or fasting. That's easy to remember. What about certain types of biohacking gear? Like, we see a lot of these advanced pieces of gear like hyperbaric oxygen therapy chambers or hypoxic training, or we talked about cold vests a little bit. But different types of stimulation like PEMF and tdcs and all these different things that folks use to stimulate their body. Or biohacking gear, I guess you would call it. Are there specific things that you think are big, big win as far as rising over and above others when it comes to increasing the tone or the health of the vagus nerve?

Nothing. Nothing crazy. I don't think there's anything crazy. But let's say I use, let's say an ISIS device. And the question is, does it stimulate the vagus nerve all over or does it stimulate it locally? So I use an ISIS device on my gut and I think it stimulates the vagus nerve. There's research.

What's an ISIS device?

Yeah, so ISIS is a variety of pemf and research shows that it can stimulate the vagus nerve. Magnetic fields in general are capable of stimulating the vagus nerve. So that's something that I use now.

And that's just spelled I C E S. Yeah.

Okay, so I have a whole post on it at Self hacked.

Okay, we'll link to that in the show notes.

Like, I did check my heart rate variability. It could do it in the long run. I haven't done that test, but when I did put it on, I didn't find my heart rate variability increase. But it could be locally. Like it's doing it in the gut because I do notice that my motility increases, the inflammation in the gut decreases. And so again, the vagus nerve.

Is this something that you. Where are you wearing this is this, like, on your head?

Once in a blue moon. I'll wear it on my head sometimes if I don't want to. Like, if I'm going to eat something that I might react to, I'll just put it on my gut and like, just my stomach. Let's say there's two different coils on each side of my belly button.

Okay, gotcha. So you can put it in different areas on your body?

Sure. Yeah.

Okay, gotcha. Okay, so we've got like a. Like an ICS device for pulsed electromagnetic field therapy. But there's no other kind of like, pieces of biohacking gear, per se, that you think works really well?

Biohacking gear? I mean, as far, there's like tongue depressors that you can use to stimulate the gag. Gag reflex. Really? And that could. Yeah, they're really cheap. They're like five bucks or something.

Literally. Like the wooden tongue depressors.

Yeah. I don't do it because it's annoying, but somebody can do that if they wanted to.

Now, why would you want to stimulate your gag reflex?

Because that's. The gag reflex is mediated by the vagus nerve. And so whenever you stimulate one area that can. That activates the vagus nerve, you can theoretically stimulate other areas. I haven't seen studies for that, but the logic, and there's a lot of people who mention it, so something I put in my post, and yeah, I think it theoretically can do that.

Okay, so is that why singing and gargling and stuff like that seems to work when it comes to increasing heart rate variability, for example?

Sure. Yeah. So singing is one of my favorite ways to increase heart rate variability. Simply because I like it. That, you know, that has a good amount of evidence for that. Even, you know, om chanting, which you can either put in, you could put that in meditation, but using your vocal cords and things like that, again, it's stimulating one area that's connected to the vagus nerve and the whole vagus nerve is connected. So that's, you know, again, that's probably why the tongue depressors and the gag reflex.

Gotcha.

Same with, like, when you make a bowel movement after you feel relaxed, what is that relaxation? It's from the vagus nerve. It's happening in one area. But since the vagus nerve is connected, you know, it has effects in other areas.

Now, what about when, you know, we talked a little bit about food, but are there specific supplements that. I mean, you mentioned this galantamine that you've used as a nootropic and also this Huperzine club moss extract. But I suppose fish oil would probably fall in there if fish works. But what else? What would be supplements that people could use to enhance the health of their vagus nerve? Like your top three? I guess I would say if you.

Are deficient in zinc, then you definitely want to do that. So, I mean, they did this study in rats where rats that were deficient in zinc, they gave them zinc and it increased their vagal activity. But I'd say my top supplements would be like, fish oil, especially if you don't eat a lot of fish. So if you're not eating fish daily, fish oil is a very reliable way to increase vagal activity, decrease heart rate. And so I've done, like mega dosing experiments, and my heart rate just went way down when I take a lot of fish oil. So that works pretty well.

Okay, gotcha. So we got fish oil. What was the one that you said? Zinc.

Yeah. And I'd say, like, probiotics. One L rhamnosis works. It increases vagal activity.

Really? And that's a specific strain of probiotic?

Yeah.

What'd you call it? L Rhamnosis.

L Rhamnosis. It's in most probiotics, though. So if you take a probiotic, it's likely that it has it.

Okay, gotcha. So L rhamnosis, probiotic, fish oil, and then any specific form of zinc that.

You recommend, just not gluconate. Gluconate is the worst. You know, it gets absorbed the least. Well, but picolinate is a good one. There's a whole bunch of them that are decent, but I take zinc picolinate.

Gotcha. Now I'm gonna link to your full article on 32 different ways to stimulate your vagus nerve in the shownotes over@BenGreenfieldFitness.com Vegas. But one last question I have for you is how can we test this? How can you actually test, test whether or not what you're doing for your vagus nerve is working besides just paying attention to the way that you. You look or feel?

So the simplest way is by your heart rate variability, which you can test with. I use a Polar H7 and for the equipment, and then I'll use Elite HRV for the software.

Okay. So you're basically using heart rate variability variability measurements.

Sure, yeah. So that, that's, that's the best way to check your vagal activity.

Okay, gotcha. And in terms of anything else regarding the vagus nerve that you'd want to share with listeners or anything that You've learned in this journey to fix your own vagus nerve. Any last tips you want to throw in there?

I would just say some of my top things. I like yoga. Yoga is another way. So I try to do yoga whenever I can, you know, so that's an easy way to increase vagus activity. One very simple way is to lay on your right side when you're lying on your back, you have the lowest vagal activity.

Like when, like when you're sleeping, you lie on your right side.

Yeah, I'll lie on my right side.

Interesting.

Yeah, it's just something simple.

I also, I also am a side sleeper on my right side.

Yeah, so I like, you know, cold showers is good, but you know, I'll get in my modes where I'll do cold showers for many months and then I'll get lazy a bit. So I do on and off. But that's probably one of the most. I'd say cold is probably the most potent way. Yoga is a very good way. And I like singing too. But some people, everybody likes doing something else. Some people like doing coffee enemas. If you're religious. Prayer has been shown to increase vagal activity. So there's really a lot of different ways you can go at this.

Interesting. Well, your article is chock full of a bunch more of these. So I'll link to this article on the show notes for people to read. And Joe, you're obviously a wealth of knowledge on this stuff, so I appreciate a lot of the stuff you're churning out over at Self hacked. And I guess the last thing is I wish you best of luck in your coding activities.

Well, yeah, I mean, I spend most of my time now with the Self decode program, which is a genetics program. There's actually a gene that is associated with lower vagal activity, so you can check that. That's interesting. It's a gene in nerve growth factor, actually.

Interesting.

So there's just, I mean, there's so many genes out there. What I'm trying to do is I'm trying to simplify it and give people a comprehensive picture. But one of them, the one with nerve growth factors, is associated with like anxiety, lower vagal. Activity. So you can check out if you have that one.

Cool, cool. And do you think you could send me a list of those genes and I'll put them in the show notes for people?

Yeah, it's mainly just one. Oh, okay.

Actually, do you know which gene it is? So if people have like 23 me results, they could search for it?

Yeah, it's Rs6330 ZNF, Rs6330.

All the these names, by the way, for those of you listening and they're super easy to search for. You said Rs6330.

Rs6330. So yeah, yeah. So Self Decode actually will look at like 6,500 snips. I have content on 600 of them. You know, decent amount of content there. And yeah, cool, I like it.

And I'll put a link to that on Snipedia, by the way, which is a good place to go to to check out snip information. Well, Joe, thanks for coming on the show today, man. I really appreciate it. And again, I'll put a link for those of you listening in in the show, notes to Joe's article and much more@BenGreenfieldFitness.com Vegas and until next time, I'm Ben Greenfield with Joe Cohen from SelfHacked.com signing out. Have a healthy week. You've been listening to the Ben Greenfield Fitness podcast. Go to BenGreenfieldFitness.com for even more cutting edge fitness and performance advice.

Sam.