Summary
Dr. Sydnee McElroy and husband Justin explore the long history of saunas across cultures, from Bronze Age sweat houses and Finnish folk medicine to Native American sweat lodges and Japanese cave baths. They discuss how sauna culture has been tied to spiritual practices, community building, and purification rituals for thousands of years, with Finland's 3.3 million saunas for 5.5 million people as the epicenter of modern sauna culture. Sydnee reviews the current scientific evidence on sauna health claims, including research on blood pressure, cardiovascular disease, stroke, dementia, lung disease, chronic pain, and depression. A meta-analysis found correlations between sauna use and reduced cardiovascular risk, though most studies are observational cohort studies conducted primarily on Finnish men, making causal claims difficult. She notes the evidence suggests sauna mimics some effects of physical exercise. The episode also covers infrared saunas, which Sydnee finds lack unique evidence compared to traditional saunas, and safety concerns including alcohol-related burns and risks of combining sauna with cold plunge for those with cardiac disease.
Key Points
- Sauna culture goes back roughly 10,000 years and appears across many civilizations, from Finnish pit saunas to Roman bathhouses to Native American sweat lodges
- Finland has 3.3 million saunas for a population of 5.5 million, deeply embedded in their cultural identity and folk medicine traditions
- A meta-analysis of sauna research found correlations with reduced blood pressure, cardiovascular events, stroke risk, and dementia, but causal links remain unestablished
- One cohort study showed a 47% risk reduction in developing high blood pressure over 25 years among regular sauna users
- Most sauna research comes from Finland and is conducted primarily on Finnish men, limiting how broadly results can be applied
- Infrared saunas have no unique evidence of superiority over traditional saunas; infrared light only penetrates 1-2 inches into skin
- Sauna's health effects appear similar to those of moderate physical exercise, including cardiovascular and stress-reduction benefits
- Major safety risks include combining sauna with alcohol (linked to burns and sudden death) and hot-to-cold transitions for those with underlying cardiac disease
Key Moments
Blood pressure and cardiovascular evidence from sauna research
Sydnee reviews meta-analysis findings on sauna and blood pressure, citing a cohort study showing 47% reduced risk of hypertension over 25 years, while noting the correlation with reduced heart attack and stroke risk has not been established as causal.
"Anyway, so because, as I said, the sauna couldn't be associated with like spiritual folk medicine, the question is: well, is it doing something for us that we can measure in an objective way and scientifically claim it's helping? So if you look at like what proponents of sauna But if you look at what they say, it's a wide variety of medical claims."
Sauna mimics exercise effects
Sydnee explains that much of sauna's health benefit appears to mimic the effects of physical exercise, and that proponents from scientific backgrounds recommend combining sauna with exercise rather than treating it as a replacement.
"In general, then that led to a lot of research on heart disease because, you know, the vasculature like veins being too, too tight, that it And so there's a lot of evidence there or a lot of research then that was done on like if you sawn irregularly, will you have fewer heart attacks? If you sauna regularly, would you be less likely to have a stroke? So you see some studies that have started to look into that. And again, most of the studies we're talking about, one, are more cohort studies, meaning we didn't randomize people. We just asked them if they saw nut or not. Two, they're mostly done in Finland."
Safety risks of sauna use including alcohol
Discussion of sauna safety, including data showing 26% of burn cases in a Finnish hospital were sauna-related (40% involving alcohol), sudden death cases linked to drinking, and cardiovascular risks of hot-to-cold transitions.
"And the answer is so varied, right? Like there are so many answers to that question. And all of them together probably are the right, you know, but, but that's a, it's bigger than one thing. With dementia, again, suggested a reduction in risk, causal link not established. Lung disease, they did see some improvements."
Infrared sauna claims lack unique evidence
Sydnee debunks infrared sauna marketing claims, noting that infrared light only penetrates 1-2 inches into skin, cannot detoxify organs, and that no research shows infrared saunas are superior to traditional saunas.
"Infrared lights, based on studies, can only penetrate one to two inches into your skin."
