#073 Sauna Benefits Deep Dive and Optimal Use with Dr. Rhonda Patrick & MedCram

Comprehensive sauna guide: cardiovascular, brain, longevity, and immunity benefits

Patrick's most thorough sauna discussion: cardiovascular benefits, Alzheimer's prevention, heat shock proteins, growth hormone, immunity.

"Once you're not familiar with what they're doing, check them out. Big thank you to MedCram for featuring this discussion and inviting me onto their show. Dr. Patrick, you are a world expert on the many potential benefits of sauna use, from better cardiovascular fitness to a lower risk of dementia to better mood, mental health, and immunity. And you're also an expert on the specific ways that people can use saunas or hot baths in many cases to maximize these benefits. What temperature should the sauna be? How long should we stay in it? How often should we use it? So really excited to jump into this, but I want to give you a brief introduction first. You have a PhD in biomedical science. You're published in a variety of reputable journals, including an excellent recent publication on saunas that was very comprehensive. And you're the co-founder of a popular website and YouTube channel called Found My Fitness. Dr. Patrick, welcome back to the show. Thank you, Kyle. I'm really excited to be here and thank you for that very kind introduction. I look forward to getting into as many details as possible about both the benefits and how we can effectively use saunas. But first, if you only had a couple minutes with someone who was totally new to saunas, how would you briefly summarize the benefits? Well, I would start with a lot of the studies that have come out of Finland, which have been 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. So, for example, people that use the sauna two to three times a week are about 22% less likely to die from sudden cardiac death compared to people that only use the sauna one time a week. But people that use the sauna four to seven times a week are 63% less likely to die from sudden cardiac death compared to people that use the sauna one 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. 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. After the sauna and after exercise, and this has actually been compared head-to-head comparison of these two, 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 interesting aspect of sauna that most people are unfamiliar with, that it's really sort of a mimicker of moderate intense cardiovascular exercise.. And then the other thing 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. 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 sonobathers. And again, it's a very dose-dependent, robust effect. Frequency matters. And so people that use this on a two to three 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 four to seven 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 one time a week. So it seems like, you know, four times a week is kind of the sweet spot. And we can talk about all the details of that in a little bit. But there's a lot of interest into why sauna use seems to help prevent neurodegenerative diseases like Alzheimer's disease and dementia. So I certainly have some hypothesis and hypotheses, I guess. They're 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 uppopulational studies finding that people that use the sauna four to seven times a week have a 40% 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. 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 health span. Our health span 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. But ultimately, improving your health span 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. And a lot of the research that has been done on the health benefits of the sauna have actually come out of Finland from Dr. Jari Laukunin'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. 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 known about the Asana's impact on that? And I think this is so important because, as you know, it's right there, neck and neck, are cardiovascular disease and cancer as the number one and two killers of both men and women in the United States. So what's known about the sauna's impact on the cardiovascular system? Well, what's known about the impact? 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. 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 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. So I think that that is partly probably responsible for some of the cardiovascular benefits. Dr. Yari Laukunen 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 four to seven 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 cardiovascular health. Excellent. And does it lower cholesterol and hypertension as well, regular sauna use? Hypertension, yes. 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 two to three times a week, they have like a 24% lower risk of hypertension versus people that use the sauna four to seven 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, 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. You mentioned how, you know, sauna use mimics exercise in many Thank you. you know, derive causality from these associations when it comes to observational studies. You mentioned how, you know, sauna use mimics exercise in many ways, moderate intensity exercise."

Sauna preserves muscle mass through heat shock protein-mediated protein folding

Heat shock proteins maintain proper protein 3D structure, preventing degradation and preserving muscle mass during aging and disuse.

"And that is, again, I think has to do with the fact of the protein folding and misfolding and how, you know, when you have that happening, proteins are, you know, it's preventing proteins from being degraded so much because they're having their proper three-dimensional structure. And so you're maintaining that muscle mass."

Sauna safety for children: more than 5 minutes can be dangerous for young kids

Children don't sweat to cool themselves like adults. In Finland, very young children are limited to under 5 minutes of sauna.

"So...and certainly like really young children, you know, I think that's, in places like Finland, I know like some children are using the sauna, but, you know, they have these cultural sort of guidelines there where, you know, there's a certain age and it's like only a couple of minutes, you know, so I'm not putting, I'm not getting my son in the sauna."