Dr. Michael Daignault
When people think of saunas, they often picture the classic scene of a group socializing after a workout or they envision the luxury of an upscale spa-like setting. Saunas are popular after an intense workout because the increased circulation from the intense heat reduces muscle soreness, improves joint range of motion and can ease pain. A small study also demonstrated that regular use can preserve muscle mass.
But did you know that frequent sauna use can also save your life? Sauna use is one of those rare health benefits that is both strongly rooted in multiple countries and cultures and has long-term research studies to back it up.
The history of the sauna
Most people think of Finland when it comes to saunas. In fact, the word sauna is Finnish and means “bathhouse.” The word association is also well-deserved considering there are more than 2 million saunas for a population of 5.5 million. But there is also some archaeological evidence that the ancient Mayans were the first known people to recognize the benefit of saunas, about 3,000 years ago, when they built sweat houses. The first saunas built in Africa were also designed to facilitate sweating to help rid the body of infectious disease.
The development of the modern sauna is thanks to Roman and Greek bathhouses. Their bathhouses were designed to purify the body but the ritual evolved into a social meeting place. Turkish Hammams were created inside beautiful ornate buildings as a safe haven to detoxify and beautify the body. Nowadays, saunas consist of a small wood-lined room heated by electrical conventional or infrared heaters.
Modern research on the benefits of sauna use
The studied benefits of regular sauna use are wide-ranging, but I'll focus on its cardiovascular disease-related mortality reduction here.
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There is an oft-cited ongoing study of more than 2,300 middle-aged men from eastern Finland who were tracked for an average of 20 years (called the Kuopio Ischemic Heart Disease Risk Factor Study). Researchers found reduced risk of sudden cardiac death, fatal coronary heart disease, fatal cardiovascular disease (CVD), and all-cause mortality in sauna users. Interestingly, the risk reduction was also dose-dependent. For example, for men who reported using the sauna 4-7 times per week, the risk of fatal coronary heart disease was significantly lower when compared to men who used the sauna once weekly. And perhaps most importantly, the risk of all-cause mortality was 40% lower among frequent sauna users.
The study findings of an association between frequent sauna use and reduction in mortality are often cited because the researchers adjusted them for potential biases and confounders like socioeconomic status, baseline physical activity and cardiovascular fitness levels. Most importantly, access was not an issue for participants, given how deeply sauna use is rooted in Finnish culture and the plethora of options available.
So how does sitting in a sauna for 20 minutes multiple times a week achieve reductions in morbidity on par or exceeding that of prescription medication and other Western medicine interventions? Sauna bathing at a temperature of 113-212 degrees Farenheint and relative humidity of 10-30% mimics a physiological response similar to moderate- to high-intensity cardiovascular exercise like cycling, swimming or running.
The high heat raises the surface temperature of the skin and the heart rate can increase to 100-150 beats a minute. A meta-analysis of multiple studies identified possible pathways for how regular sauna bathing could reduce the risk of cardiovascular disease and mortality, including:
- Reduction in blood pressure
- Improved function of the endothelium, the thin membrane lining inside of heart and blood vessels, and relaxed blood flow
- Reduction in oxidative stress and inflammation
- Positive modulation of blood cholesterol levels; increased HDL and decreased LDL
- Positive impact on the autonomic nervous system
These benefits make sense because dysregulation of these pathways can lead to chronic diseases such as diabetes, high blood pressure, high cholesterol and other risk factors for coronary artery and cardiovascular disease.
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Should you spend more time in a sauna?
If you have access to a sauna and are considering incorporating it into your routine, first discuss with your doctor as you would before starting any kind of new exercise regimen. Remember, using the sauna induces the same physiologic response you would experience from an intense workout. Sauna use is not recommended for those with a history of low blood pressure, recent heart attack or stroke, and individuals with altered or reduced sweat function. Pregnant women and children should also avoid the sauna.
An additional word of caution: in a typical session, the average sauna bather can secret half a kilogram of sweat – about 1.1 lbs. Hydrating is essential after a sauna session!
If you don’t have access to a sauna, I highly recommend cycling heat and cold exposure as often as possible at home. Before bed, add two scoops of Epsom salt for a comfortably hot 20-minute bath. Then rinse off with a 5-minute cold shower. Set the bedroom temperature to 65F to optimize cellular recovery overnight.
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Michael Daignault, MD, is a board-certified ER doctor in Los Angeles. He studied Global Health at Georgetown University and has a Medical Degree from Ben-Gurion University. He completed his residency training in emergency medicine at Lincoln Medical Center in the South Bronx. He is also a former United States Peace Corps Volunteer. Find him on Instagram @dr.daignault
