How Sauna Frequency Relates to Cardiovascular Health

Kyle Allred: If you only had a couple minutes with someone who was totally new to saunas, how would you briefly summarize the benefits?

Dr. Rhonda Patrick: Well, I would start with a lot of the studies that have come out of Finland, which have been, you know, very, very large population-based studies. These are observational studies where an association has been made, and there have been quite a few that have found that frequent sauna use is associated with a lower risk of death from cardiovascular disease, a lower risk of sudden cardiac death, a lower risk of coronary heart disease, a lower risk of stroke, a lower risk of dementia, of Alzheimer's disease. And when I say a lower risk, it occurs in a dose-dependent manner. So what that means is the more frequent the sauna bathing, the more robust the health benefits are.

Dr. Rhonda Patrick: So, for example, people that use the sauna 2 to 3 times a week are about 22% less likely to die from sudden cardiac death compared to people that only use the sauna 1 time a week. But people that use the sauna 4 to 7 times a week are 63% less likely to die from sudden cardiac death compared to people that use the sauna 1 time per week. So there's a dose-dependent effect with more frequent sauna bathing, more robust effects on cardiovascular health. And, I would say that to people that are not familiar with the sauna, a lot of people think of it as a time to relax. It's a time to take some space out of your day and have it to yourself.

Dr. Rhonda Patrick: So, there is an aspect of this relaxation, almost a meditation type of quality to sauna bathing, but there's also a very interesting aspect of it, which is sauna use is essentially mimicking moderate aerobic cardiovascular exercise. And so a lot of the same physiological responses that happen when you're exercising, for example, your heart rate elevates while you're exercising, you elevate your core body temperature, you get hot, you start to sweat. These are the same things that are occurring while someone is in the sauna. So heart rate elevates. It elevates to around 120 beats per minute. You sweat, your core body temperature is elevated.

Dr. Rhonda Patrick: After sauna and exercise—and these two have actually been compared head-to-head—blood pressure is lower after sauna bathing or after exercise. Your resting heart rate is lower than before you did the exercise or before you started using the sauna. So I think that's also a really—

Kyle Allred: Yeah.

Dr. Rhonda Patrick: Interesting aspect of sauna that most people are unfamiliar with, that it's really sort of a mimicker of moderate-intensity cardiovascular exercise. And then the other thing is, is that there seems to be really profound effects on the brain. And I don't think all the mechanisms have been teased out just yet. We can certainly dive into some details, but, you know, there's obviously a very strong link between cardiovascular health and brain function.

Dr. Rhonda Patrick: You know, having proper blood flow to the brain is very important for lowering dementia risk. So there's definitely that aspect there. But, you know, there's been some observational studies looking at dementia risk and Alzheimer's risk in sauna bathers. And again, it's a very dose-dependent robust effect. Frequency matters. And so people that use the sauna 2 to 3 times a week you know, they have somewhere like a 20% lower dementia risk, 20% lower Alzheimer's risk, more or less. But using the sauna 4 to 7 times a week, it's associated with between a 60 to 66% reduction in dementia and Alzheimer's disease compared to people that use the sauna 1 time a week. So it seems like, you know, 4 times a week is kind of the sweet spot, and we can talk about all the details of that in a little bit.

Dr. Rhonda Patrick: But there's a lot of interest into why sauna use seems to help prevent neurodegenerative diseases like Alzheimer's disease and dementia. I certainly have some hypotheses—I guess there is more than one. So I'd love to dive into some of that. But I think that's a kind of a good start into the sauna. Oh, and also all-cause mortality. That's a really big one too, because you know there's been these studies, these large population studies finding that people that use the sauna four to seven times a week have a forty percent lower risk of dying from all causes of death than people that use the sauna one time a week. So to me, it really is the beginning of understanding that, you know, sauna use seems to really be beneficial for our health.

Dr. Rhonda Patrick: And much like a lot of these lifestyle factors that are well known to modify our disease risk, so exercise, for example, so you don't want to be sedentary. Good sleep, you know, a healthy diet, meditation. I think these are pretty common knowledge at this point to be beneficial for overall health. And I think that sauna use should be up there. I think it should be included in that sort of, you know, bag of things that are known to improve what's called our healthspan. Our healthspan is— it's basically compressing the diseases that we get into a shorter time period. So it's essentially extending the youthful part of our life. So you may not necessarily live, you know, X many years longer, although you may if you don't get cancer earlier. You'll probably end up not dying from cancer earlier.

Dr. Rhonda Patrick: But ultimately, it's healthspan— improving your healthspan is about improving the quality of your life, not getting Parkinson's disease, not getting Alzheimer's disease, not getting cancer, not getting cardiovascular disease, type 2 diabetes. And having a better quality of life so that you're essentially enjoying your life and living healthier for a longer period of time. I do want to make sure to distinguish the difference between my publication on the sauna, which was a very comprehensive review article covering multiple aspects of sauna health, and someone doing primary research where they're actually doing experiments and having people, you know, come into a sauna and measuring heart rate and blood pressure changes, for example. So I am not doing those experiments.

Dr. Rhonda Patrick: And a lot of the research that has been done on the health benefits of the sauna has actually come out of Finland from Dr. Jari Laukkanen's lab in Eastern Finland. And so I just wanted to give him a little shout-out because his work has been invaluable in our understanding of the health benefits of the sauna.

Kyle Allred: Well, let's start by diving in a little bit deeper into the cardiovascular system, because you mentioned there's some potentially excellent benefits from the sauna on the cardiovascular system. So could you review what the cardiovascular system is briefly, and then what's, what's known about the sauna's impact on that?

Kyle Allred: And I think this is so important because, um, as you know, it's right there neck and neck are cardiovascular disease and cancer as the number 1 and 2 killers of both men and women in the United States. So what's known about the sauna's impact on the cardiovascular system?

Dr. Rhonda Patrick: Well, what's known about the impact— so I mean, I think generally speaking, when people think about cardiovascular health, they think about their cholesterol, they think about the health of their arteries, they think about not having a bunch of plaques build up inside their arteries and block blood flow and oxygen from getting to different tissues. It's definitely known that a lot of dietary and lifestyle factors can modify cardiovascular disease risk, one of the best ones being exercise.

Dr. Rhonda Patrick: I don't know that there's anything better for cardiovascular health than exercise. So, you know, the fact that sauna use mimics moderate-intensity cardiovascular exercise, as I mentioned a moment ago, is—it's just sort of like this proof of principle that, you know, sauna is going to be good for cardiovascular health. The same sort of physiological changes are happening. You know, you have an increased blood flow to the skin, also to the muscles, so that's to help facilitate sweating. Plasma volume increases, heart rate elevates during sauna bathing. You're getting hot, you know, you're getting hot and sweating, and you're doing the same thing that's happening while you're exercising. And changes in blood pressure go down as well afterwards, just like exercise.

Dr. Rhonda Patrick: So I think that that is partly probably responsible for some of the cardiovascular benefits. Dr. Jari Laukkanen and his colleagues have looked at so many different aspects of cardiovascular health with respect to sauna bathing, and they found time and time again, whether you're talking about sudden cardiac death, whether you're talking about death from cardiovascular disease or coronary heart disease, and even talking about stroke risk. Stroke risk is also significantly lowered, something in the realm of like 40% lower for people that use the sauna 4 to 7 times a week versus once a week. So there's a really large body of evidence that suggests that sauna use does mimic moderate aerobic activity, and this is potentially why it's beneficial for cardiac, you know, for cardiovascular health.

Kyle Allred: Excellent. And does it lower cholesterol and hypertension as well, regular sauna use?

Dr. Rhonda Patrick: Hypertension, yes. Like, so there's been some studies looking at hypertension risk. So again, these are observational studies. And again, it's one of those dose-dependent effects where you see people that use the sauna 2 to 3 times a week.

Kyle Allred: Uh-huh.

Dr. Rhonda Patrick: They have like a 24% lower risk of hypertension versus people that use the sauna 4 to 7 times a week who have about a 46% lower risk of hypertension. But there's also been just like studies where they've looked at a single sauna use, again, where they just— when a person goes into the sauna, uses it for, you know, 20 minutes, and they measure blood pressure before and after the sauna.

Dr. Rhonda Patrick: And even just a single sauna use lowers blood pressure, so both systolic and diastolic blood pressure after the sauna bathing, similar to what exercise does. And so, I think that helps sort of establish causality because there's always a question about associations and how much association, how much can you, you know, derive causality from these associations when it comes to observational studies.

Kyle Allred: You mentioned how, you know, sauna use mimics exercise in many ways, moderate-intensity exercise. So, with regard to that, can it also just improve overall fitness and endurance as well?

Dr. Rhonda Patrick: That's a great question. My co-author, Teresa Johnson, and I cover this in our review article.

Dr. Rhonda Patrick: And I'd say, so far, the evidence seems to suggest that sauna use may improve endurance exercise. There have been a variety of studies that have looked either at runners, for example, that use the sauna, and then they're able to improve their time and running distance. There have been some studies looking at people wearing a sauna suit. So this is like a type of clothing that's put on that sort of mimics the sauna because it makes you, you know, warm up. And so people train in that sauna suit, and that's been shown to help improve endurance. But I think there's a lot of evidence out there looking at just acclimating yourself to heat. And so, you know, when you're getting in the sauna, there's these physiological changes that start to occur where your body starts to adapt.

Dr. Rhonda Patrick: So, like, if someone's never used the sauna before, it's really hard to stay. And we haven't talked about temperature duration yet in any of these, you know, studies that I've referred to with respect to cardiovascular health and all-cause mortality, for example. But, you know, if you're getting in a hot sauna that's 175°F and you've never done that before, and certainly if you're not someone that's physically active, you know, people that are physically active also are sort of adapted to heat because they're elevating their core body temperature when they're physically active, and so they're a little more heat-acclimated.

Dr. Rhonda Patrick: So you take a person that's not, you know, a person that's sedentary, not acclimated to heat, and it's going to be hard for them to stay in that sauna, hot sauna, for more than 5 minutes. But as time goes on and as people start to use the sauna more and become more acclimated, then people start to sweat at a lower core body temperature, and this helps facilitate cooling down. And so they're able to tolerate it more. And they also— there's some other adaptations that we can talk about at the molecular level that occur as well.

Dr. Rhonda Patrick: And so I think that it all comes down to basically, if you are adapted to heat well, then when you're doing your marathon, you're going to be, you know, more heat adapted because if you're used to using the sauna and you're, you know, you're sweating at a lower core body temperature and all these physiological changes are happening, then that's going to affect you when you're also elevating your core body temperature through another modality, that modality being running or exercise, you know, fill-in-the-blank type of exercise. So, you know, it kind of makes sense when you think about it.

Kyle Allred: Definitely.