Emerging evidence suggests that beyond its use for pleasure, sauna bathing may be linked to several health benefits including cardiovascular, neurological and metabolic benefits. A recent review by Patrick & Johnson outlines evidence of the benefits of sauna use, potential mechanisms of action, and adverse effects and contraindications. Sauna bathing is characterized by short-term exposure to high temperatures (ranging from 113F to 212F), and there are various forms including “dry” and “wet” saunas which differ in the amount of humidity.
A large study done by Laukkanen et al., examining data from over 2000 middle-aged men in Finland showed that men who used saunas two to three times a week had a 27% reduction in mortality associated with cardiovascular disease compared to those who used saunas once a week, and men who used saunas four to five times a week had a 50% reduction rate in mortality associated with cardiovascular disease. The risk of mortality from all causes was reduced by 40% in frequent sauna users compared to infrequent users! Duration of sauna use was inversely correlated with the risk of cardiovascular disease and coronary heart disease, meaning those who used saunas for longer than 19 minutes had better outcomes than those who used saunas for less than 11 minutes. Results were adjusted for factors such as socioeconomic status.
Many of the physiological effects of sauna use are similar to those elicited during moderate to vigorous-intensity aerobic exercise. Studies show that aerobic exercise in combination with frequent sauna use has a synergetic effect in reducing cardiovascular and all-cause mortality. Exposure to high temperatures stresses the body and this heat exposure induces protective responses that promote cardiovascular health, such as increased heart rate, decreases in blood pressure, and improved blood flow. Heat stress may lead to improved physical fitness by increasing cardiorespiratory fitness, endurance and preserving muscle mass. During exercise the core body temperature rises and heat acclimation from the sauna optimizes the body for tolerating core body temperature elevations during future exercise, as well as supporting other cardiovascular and thermoregulatory functions that are important in fitness and exercise. pThese mechanisms contribute to muscle mass maintenance and prevent muscle loss that can occur with aging.
Further analysis of the data from Finland also showed that men who used saunas four to seven times a week had a 66% lower risk of developing dementia compared to those who used saunas once per week. Proposed mechanisms for improved brain health in response to sauna include heat exposure and the subsequent cardiovascular response increasing the expression of brain-derived neurotrophic factor (BDNF), which is an important factor that supports the development of new neurons in the brain, and increased blood flow to the brain. Heat shock proteins also protect against brain disease.
Findings from the study also show that regular sauna users had a lower risk of developing pneumonia and sauna use may bolster the response of the immune system and promote respiratory health.
Caution should be exercised for sauna use in special populations such as pregnant women and children. There are some reports of reduction in male sperm count following sauna use in a 10-person study, but measures returned to normal within 6 months of sauna use cessation. Some contraindications for sauna use include alcohol use, hypotension, recent heart attack, severe aortic stenosis, and altered or reduced sweat function (such as in certain autoimmune or neurological disorders). Proper hydration is recommended prior to and during sauna use.
You may want to consider using a sauna as you cultivate a positive, healthy lifestyle. It can be pleasant and soothing on a cold winter’s day, and may reduce your risk for some upper respiratory infections. There is no clear evidence indicating whether the benefits of sauna are limited to specific climates or seasons, or whether sauna bathing during hot weather confers health benefits.
Patrick RP, Johnson TL. Sauna use as a lifestyle practice to extend healthspan. Exp Gerontol. 2021;154:111509. doi:10.1016/j.exger.2021.111509
Laukkanen T, Khan H, Zaccardi F, Laukkanen JA. Association between sauna bathing and fatal cardiovascular and all-cause mortality events. JAMA Intern Med. 2015;175(4):542-548. doi:10.1001/jamainternmed.2014.8187