FoundMyFitness - #037 Dr. Jari Laukkanen on Sauna Use for the Prevention of Cardiovascular & Alzheimer's Disease

Episode Date: June 15, 2017

Jari Laukkanen This podcast features Jari Laukkanen, M.D., Ph.D., a cardiologist and scientist at the Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio. Dr. Laukkanen has been conducting long-term trials looking at the health effects of sauna use in a population of over 2,000 middle-aged men in Finland.  In this episode, you'll discover:  (00:00) Introduction (01:50) Sauna use improves cardiovascular health and reduces risk of death (06:42) How sauna use lowers blood pressure  (08:07) Sauna use mimics aerobic exercise, increasing heart rate up to 150 beats/min (09:40) How long should you stay in the sauna? (11:59) Heat shock proteins help keep the brain healthy  (14:52) Sauna use increases growth hormone and improves response to exercise (17:43) The positive effects of sauna on mood may be due to endorphins (20:58) Finnish sauna culture and adding cold-water immersion to the sauna experience If you're interested in learning more, you can read the full show notes here. Join over 300,000 people and get the latest distilled information on sauna use straight to your inbox weekly: https://www.foundmyfitness.com/newsletter Become a FoundMyFitness premium member to get access to exclusive episodes, emails, live Q+A's with Rhonda and more: https://www.foundmyfitness.com/crowdsponsor

Today's podcast features a conversation I had when I was in Finland with one of the world's foremost researchers of the sauna, Dr. Yari Laukonen. Yari holds a PhD and an MD. What makes this conversation very interesting is that Yari not only comes to it as an actual researcher of the sauna, but also as a cardiologist. Often when I talk about the sauna, I may sometimes refer to animal studies, especially when it comes to molecular evidence. But it is Dr. Lalkinen's lab that actually makes the single most convincing case

that sauna use has real benefits in humans. It is his research that has shown that long-term sauna use appears to reduce heart-related mortality, but even more surprisingly, also may have a strong effect on what is known as all-cause mortality, which literally means death from all causes, which sounds a whole lot like longevity, if you think about it. Moreover, since this conversation was recorded, Dr. Lalkinen's lap released yet another publication, which showed a really strong association with the reduction in the risk of dementia and Alzheimer's disease by 66% and 65% respectively at a 20-year follow-up, which further strengthens the case that sauna therapy may be more than just relaxing, but may actually be a great tool for even improving health span. In both the

studies showing reduced memory illness and reduced all-cause mortality, the effect follows a dose response relationship with the group showing the strongest reductions in risk by frequenting the sauna at least four times a week for at least 20 minutes at 174 degrees Fahrenheit or 79 degrees Celsius. In fact, one of the more interesting observations made by Dr. Lalkinen in this podcast is that time spent in the sauna appears to be a very important factor, with shorter sauna durations having a much less robust effect. Okay, enough preamble. Let's get this show on the road. On to the podcast. Hello, everyone. I am in Finland, sitting here with Dr. Dr. I'm a little excited to be sitting here with Iari Yari because I've talked quite a bit

about his research involving using saunas and how that has been shown to improve cardiovascular health and also improve overall longevity. And to my knowledge, this is actually your work is the first research that I've actually seen in humans to show that using that using the sauna, you know, can improve longevity. Maybe we can start off by talking about this study that you look, that you did on published about a year ago, I believe, in the Journal of American Medical Association, Jama, looking at sauna, sauna, the use of the sonas and sauna frequency and cardiovascular related mortality and overall mortality rate. Yeah. So can you tell us a little bit about the study itself? Yeah, yeah, yeah. Thank you. Our study is based on middle age population

from Eastern Finland, and at baseline we measured the use of sauna how many times per week and how long time per one session on what was the temperature. And on the basis of this information, we have studied the association between the use of sauna and fatal cardiovascular outcomes and mortality. And in this study we found really that sauna use was inversely associated with the risk of fatal coronary heart disease events and all-cause mortality. And after adjustment for other risk factors, which have been also measured in this big population-based study, there was still significant association between the use of sauna and these outcomes. Yeah, so if I remember correctly, your study showed that men that used the sauna two to three times a week had a 27% lower cardiovascular-related mortality compared to men that used it one time a week. And men that used the sauna four to seven times a week actually had a 50% lower cardiovascular-related mortality than men that used the sauna one time a week.

And that is very robust. Yeah. I mean, so you followed these men for 20 years? Yeah, yeah. The total follow-up time was 20 years and we have annually measured new outcomes and we have followed carefully from baseline until the end of the follow-up. And yes, the risk reduction was really, really obvious and clear. And you said you adjusted for other risk factors, meaning like obesity, you looked for people like obesity, smoking, alcohol, cholesterol, Asterole, Type 2 diabetes, these sort of factors.

Yeah. If I remember correctly, you also looked at socioeconomic status and physical activity, which is important. Yeah. So these are all, the data is reflective really of sauna use. Yeah, yeah. Not, you know, because people that use the sauna tend to also exercise more. So, you know, it's that you have to correct for all those other possible confounding factors,

which you did. Yeah. So the cardiovascular rate of mortality, were there certain, like, you have, like, you have There's certain, like were you measuring all sorts of different ways people can die from heart failure, like coronary artery disease, heart attack, there's certain like atherosclerosis, was that looked at? Was it multiple different types of outcomes? Yeah, yeah, there were different kind of outcomes. There were heart-related, like coronary heart disease, mortality, and also sudden cardiac death was the one of the outcome.

then we have overall cardiovascular disease death as an outcome and then also all-cost mortality. And there was a significant association with all these outcomes. Right. We'll get to all-cause mortality in just a minute, but I kind of want to talk about the cardiovascular-related mortality is it's so important because I know in the United States heart attacks or the cardiovascular disease is the number one killer, followed up by cancer and then respiratory. diseases, but Alzheimer's disease is actually climbing up. In Finland, I believe, cardiovascular disease is also number one killer, correct? Yeah, it is still in one. Yeah. So, you know, if you can do something that lowers your risk by, you know, 50 percent, I mean, that's very significant. Yeah. What do you think, I have my own sort of, you know, I've done some reading on, on how the sauna

affects in different vascular functions, but you're a cardiologist. So do you have some sort of, do you speculate on some of the mechanisms by which using the son? sauna can improve cardiovascular health? Yeah. Yeah, we have been studying also these mechanisms, which can be explained to our findings. And one of the most important is the blood pressure because long-term sauna use can decrease blood pressure level. Actually, we have studied in the same population and found that there is a reduction of incident hypertension among those who are using more sauna compared to those who have only, let's say, one session per week. And so blood pressure is one of the most important factor which can explain the findings. And do you know why sauna

lowers blood pressure? Do you? There may be many reasons. We know that it can balance autonomic nervous system as well and also it can improve the vessel function. Endothelial cells? Yeah, endothelial cells. And another thing is that the sauna may have some effect on arterial stiffness and compliance of arteries can improve after long-term sauna use. Wow. So a lot of these parameters that you just described are also

also known to be affected by cardiovascular exercise. Yeah. Right? Yeah. Aerobic exercise. So I have to mention that, like, you know, as someone that uses the sauna, when you sit in the sauna for, you know, long enough period of time, your heart rate starts to elevate as if you were doing cardiovascular work.

In fact, I think it's something like a hundred or... Twenty or 150? 150 beats per minute. Yeah. It is quite high, actually. It is something like the moderate level of physical activity. So you mentioned the duration, the time people spent in the sauna also was an important factor on the robustness of lowering cardiovascular-related mortality.

So people that stayed in the sauna, I believe it was longer than 19 minutes, had the most robust effect compared to men that stayed in less than 11 minutes. Yeah, yeah. Yeah. The risk reduction can be seen among those who were more than 20 minutes per session in sauna, there was a risk reduction among those men. Yeah. I'm always sort of hesitant to tell people, like, they ask, you know, well, how long should I stay in the sauna? Because on the one hand, you don't want to stay in too long. But you also don't want to not stay long enough to get these important benefits, you know, cardiovascular benefits. So do you have any sort of parameters that are guide that, you know, someone that's trying to figure out how long to stay in the sauna in order to get this sort of benefit, how long they should stay in? Probably depends on temperature as well. Yeah.

Yeah. On the base of this study, we defined the 20 minutes could be enough. But at the moment, actually, we are exploring more carefully what could be the time what's needed to stay at the sauna. Oh, okay. And it can be that very short time, let's say, 10 minutes or 15 minutes. It's not enough to get all these health benefits maybe. So we try to clarify what is the optimal time to stay in sauna. Great.

So you're working on those parameters right now. What was the average temperature that the sauna that these men were using? How hot was it? It was 79 Celsius. 79 Celsius. So about 20 minutes in the 79. degree Celsius sauna was what was important for, at least in the context of the lower cardiovascular related mortality and also all-cause mortality as well. Yeah. That was our primary finding. Yeah. And what

was the type of sauna that these men are you, because this is Finland, right? Yeah, yeah. It's Finland. Yeah, it is for us, it's clear that it is Finnish dry sauna. Yeah, it's relatively dry. Relatively dry. So they weren't doing that, what's it called when you dump the water on. Lolo? Low loo. So when you make the humidity, you do the low loo. Was that also?

It was also allowed. So the all-cause mortality is also interesting because your study showed that, again, there was a dose-dependent effect where men that used the sauna two to three times a week had a 24% lower all-cause mortality than men using it one time a week. And I believe it was men using it four to six. seven times a week was a 40%? Yeah, it was, yeah, yeah. 40%.

We are calling those those response relations. Right, yeah. You're getting ready to publish, a paper was accepted that you're going to publish, which will probably be published by the time this video is published. So that's really exciting. So you found that sauna use is associated with lower Alzheimer's disease and dementia. That is extremely interesting.

me because, you know, of my interest in heat shock proteins. So the sauna, one of the most robust molecular mechanisms, you know, that happens upon heat stress. So when you heat stress the body, what happens is you activate a signaling pathway called heat shock proteins. They play a very important role in maintaining the three-dimensional structure of a protein, which is important, obviously, for proteins function, but it's also very important for the half-life of a protein. And when the three-dimensional structure of a protein becomes misfolded because of damage that's occurring, you know, damage that, damages our DNA, the same damage that does that damage is proteins. You know, byproducts of normal metabolism, reactive oxygen species,

byproducts of, you know, immune activation, these things are damaging our proteins, our DNA, our cells. But heat shock, so when those proteins become damaged, they miss. fold and they don't get degraded properly. So when this happens in the brain, you know, proteins can start to then aggregate and form these plaques, protein aggregates and plaques. So probably the most well-known one is amyloid beta-42, which is associated with Alzheimer's disease. But interestingly, heat-shock proteins, what their function is inside of the cell is to actually repair a misfolded protein so that it maintains its proper. three-dimensional structure again.

So they're basically preventing the protein aggregation, and this has been shown in multiple studies in rodents, in lower organisms. There's been many, many studies, associated studies looking at heat chock proteins and neurogenital diseases. So there's a lot of interest in how heatchog proteins may be a therapeutic target for preventing neurodegeneric diseases like Alzheimer's and also Parkinson's disease. And I've always thought, you know, the connection between knowing the sauna activates heat chalk proteins. I mean, that's their name. They're, you know, they're activated under

conditions of stress, particularly heat stress. So I think that would be a very interesting thing to look at. I think there are some interesting findings, some acute changes after sound is, yeah, single session in vessel and vessel function. Oh wow. And also heart rate. And there's actually quite, there's gradual increase in heart rates during the single sound session. Yeah, I've noticed that in myself. Yeah, yeah, yeah. It is, when you stay, let's say, 15 minutes in sauna, it's quite easy. It's not demanding, but after that it becomes more and more demanding to stay in sauna and your heart rate will increase.

I know there's a bunch of endocrine factors that increase quite dramatically upon just even a single sauna session, like for one, growth hormone. Growth hormone, yeah. The hormone goes up like 200 to 300 percent, like even after a single sauna session. Yeah, it's quite much. Yeah. So, and growth hormone, you know, it plays an important role in muscle, preventing muscle atrophy, which is also linked to longevity, right? The more muscle mass you have and more muscle strength is associated with lower all-cause

mortality. So that would be interesting to see if that's also related. Do you have any thoughts on whether or not, like someone who's doing, physical activity, like doing some kind of workout exercise, whether they should use the sauna before or after their workout? Yeah. This is a very interesting question to see if there's even more clear effects on vessel function and so on.

If you have a exercise before and then you go to sauna. Actually, we are normally doing that quite often in Finland, yeah, Finland. So you normally do the sauna after exercise after workout? Yeah. Yeah. That's what I do as well. You know, and if you think about it, too, it's also the perfect time to get that growth hormone boost, you know, because it just works your muscles. So you need that repair.

And also the exercise primes your muscles to take in the growth hormone. And it also, you know, take in actually IGF1, which is downstream of growth hormone. So your IGF1 goes into the muscle tissue and also into the brain. So the exercise sort of primes that IGF1 that's released down. on stream of growth hormone from the sonate to go into the brain, where it plays a role in actually helping BDNF, brain-derived neurotrophic factor in growing new neurons. So it's always sort of a question, like, do you do it before, a workout or after?

I've always been inclined to do it after a workout, but it would be interesting to know if there's, you know, specifically if it's affecting vessel function or things like that. Yeah, yeah. Yeah, we are very interested to see the effects on vessel function after after exercise, which is combined with sauna and what are the parameters, what are the values after that. And because there are also some evidence that maybe after strength training, you know, it can be

even that arterial stiffness may increase a bit, maybe, in some case. So if you go to sauna, you can relax and improve your vessel function also. So it may be better to do the sauna after. strength rings. Yeah, yeah, but yeah, this is, yeah, we have now, you know, speculating, of course, yeah, yeah, yeah, I mean, that's okay to speculate. Speaking of speculating, so something else that I find very interesting is the effect on mood. Actually, it's what got me interested in the sauna in the first place, so when I was in graduate school, I was very stressed out, you know, exams and failed experiments and lots of

pressure, so I was using the sauna and it noticeably, improved my mood. And it helped me deal with stress. It helped me deal with the anxiety I was experiencing. And there's a lot of sort of speculative reasons I think that's possible, but one is related to cardiorespiratory fitness. So there's actually been studies, one very recently done, published, in a very large sample of people, I believe it was like a million people. Looking at cardiorespiratory fitness and depression, and the study found that people with poor cardiorespiratory fitness had a 75% increased chance of being, have been, you know, diagnosed depression. So I'm sort of interested in, clearly the sauna is affecting, you know, cardiovascular

health. And do you know, like, cardiovascular fitness would be, you know, one way to, a measurement of cardiovascular health. Have you ever looked at cardiorespiratory fitness? Yeah, we have been measuring also cardiovascular fitness in our study. Also in this new study part, we have measured and we can see if there is an association between the fitness and sauna use and these different parameters. So that's ongoing right now. Yeah, ongoing. In our population-based study, although we adjusted for the level of fitness, they're also

independent associates between the use of sauna and outcomes. Oh, cool. So you're saying, you know, in addition to people, obviously, they're, that are physically active, you're adjusting for that and then trying to look just specifically at how the sauna may in and of itself affect the rest of fitness. That'll be really great. I look forward to that. The other one, which I won't get into too much detail because I don't want to talk so much, but it affects endorphins. So sauna releases endorphins. Dorphins make you feel better. Feel better, yeah, yeah. Yeah. It is relaxation, yeah. Also in Finland, I think quite many

use for that purpose. They want to some relaxation, you know, after working day and so on, it's like a happy to end your day and go to sauna and after that you feel more relaxed. Do you think that that may also have something to do with the improved longevity? Because stress is also linked to longevity. And so if it's something that's lowering stress and making you more relaxed, then that seems like it goes hand in hand with longevity as well. Yeah, can be. Can be. And there are studies showing the role of autonomic nervous system and cardiovascular diseases, how they are related together. And also in our study, we want to explore how the sauna may have effect on heart rate and heart rate variability, which is one of the measure which can be used to assess the autonomic

nervous system and its function. having been in Finland now for a few days and having the privilege of going to the Finnish sauna society and also hanging out with some other friends here in Finland, I've had a chance to experience the sauna culture, the traditional smoke sanas, and also the other dry saunas and the low lo lu. Lolo, yeah. But what I also noticed is that almost 100% of the Finnish people that I, that use the sauna, after the sauna, like to go run into and jump into a cold lake or the Baltic

or something cold, very, very cold. And they do this, you know, several times. I mean, this is, it seems to be a very normal part of Finnish sauna culture. Yeah. Is that accurate, you would say? Yeah, yeah, many people are using. I know it, yeah, yeah. So I have a question on whether, you know, what is the safety, you know, is there any safety issues?

Because I've read a couple of case reports where because you're going from hot sauna where vasodilations occurring and then you're going into cold where vaso-constrictions occurring, norapherence being released and laser constrictions occurring, there have been a couple of documented cases of like coronary artery spasm, I think it's called. Maybe, do you think there's a potential risk of going from hot to cold in terms of people with maybe a pre-existing heart disease or something? Yeah, among those patients who have coronary heart disease, and especially if it's not stable condition, then you have to be very careful. You cannot do that because there can be spasm in coronary arteries and it can be harmful, yeah. But for the most part of the population, it seems to be pretty safe. I mean, I've done it before, and it feels really good. I mean, you feel amazing after doing the hot and cold.

Also interested in if it blunts any of the positive effects. But what's interesting is I've seen that cold also activates heat shock proteins, because heatchog proteins are part of the stress response, you know. It's sort of, it's called hormetic stress. Are you familiar with hormesis? It's like a little bit of good stress where it's not too much stress, but it's enough stress to activate all these genetic pathways that help you deal with stress. Well, heat shock proteins are one of those genetic pathways. And so cold is also a little bit of a hormetic stress.

And exercise activates heat shock proteins as well. And the heat robustly activates them very robustly. So the cold shock, it's good to know that both the hot and the cold are activating some of the same good genetic pathways. So maybe you're not negating all the good stuff you just did with the sauna, right? Maybe there's synergy. We would be really happy to investigate those possible mechanisms between sauna and memory disease. Absolutely. Because we have been thinking through more like improved cardiovascular system and circulation on these

if they have an effect on the memory diseases because some cardiovascular diseases and memory diseases are sharing the bit similar risk factors. Right. Yeah, like fast. Of course, yeah, blood flow is absolutely linked to dementia. So it's probably multiple mechanisms by which the sauna, man, it's just, it's great. We've got to get the word out there, you know, more research, more people using the sauna. I think that's...

Because I think that there are, nowadays there are so many studies showing to positive effects of physical exercise on these outcomes and vessel function. but there are quite limited data on sauna use and warm exposure and these similar outcomes. So there are space to do these kind of research. Yeah, you're like, you're like, you know, an explorer in new territory. No one's really doing this, you know, and it's really great. I'm very glad that someone is, you know, so please keep up the good work. And in the best case, of course, we can combine these positive effects in like exercise and sauna. Are you going to look at that as well?

Are you going to see if there's a synergy? We try to do something. What is also important for public health level, that also we have to emphasize that there are many other factors in addition to exercise and sauna. There are other also. Of course, we have to take care of other risk factors, like blood pressure, lipids, smoking, obesity, in addition to that.

Cool. Well, Yari, thank you so much for taking time to speak with me. And I know you're on Twitter. I follow you on Twitter. your Twitter handle, do you want to say your Twitter handle name? Because it's your name backwards, I think. Yeah, you're welcome to follow you. Can you spell it out for people?

So it's... Yari, Lakhine. Right, but your Twitter handle is Laokan and Yari, I think. Yeah. So, yeah, L-A-U-K-K-K-A-N-E-N-J-A-R-I. That's your Twitter handle. Yeah. Okay, excellent.

Well, thank you again, Yari. Thank you. so much. Special thanks to Dr. Laucan for meeting with me and for even making special allowances for my unpredictable schedule while I visited Finland, allowing me to drop in his home late in the evening for a quick conversation. If you want to learn more about the effects of the sauna on cardiovascular disease, Alzheimer's disease, all-cause mortality, exercise performance, and muscle mass, get on my email newsletter. I send out great articles not only on these topics, but many other topics as well. You can find that newsletter sign up as well as a longer informative report on

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