For the last three decades, scientists in Eastern Finland have been researching the effects of sauna bathing on thousands of men and women—and have uncovered some amazing trends.
More specifically, this research, known as the Kuopio Ischemic Heart Disease Risk Factor Study, examined how frequent sauna bathing as a leisurely activity happened to affect common disease risks such as cardiovascular disease, coronary heart disease, stroke, and all-cause mortality.
Fast forward to just a few years ago and a paper was published demonstrating the dose-dependent effect sauna bathing had on the cohort’s risk for sudden cardiac death, cardiovascular-related death, and fatal coronary heart disease. In this case, the dose was the amount of times the sauna was used in a week, and the amount of time each individual tended to spend in the sauna.
It showed that men who used the sauna 2 to 3 times per week for about 15 to 20 minutes had an 18% reduction in the risk of fatal coronary heart disease—but those who went 4 to 7 times a week experienced a further 20% reduction in risk.
After that initial research was published, additional studies have uncovered the dose-dependent benefits of sauna use on stroke and hypertension.
Since the cohort is Finnish men and women, it’s worth taking a moment to go over how the Finns like their saunas. Finnish sauna bathing is almost always a dry sauna at about 174 degrees Fahrenheit (80 degrees Celsius) with 10% to 20% humidity coming from steam as the bathers typically throw water onto hot rocks. The mean duration for sauna use was about 19 minutes or more.
One of the reasons sauna bathing works to reduce the risks for these diseases is that as blood moves from your core to your skin to facilitate sweating in the hot environment of the sauna, your heart starts to beat faster—up to 150 beats per minute to encourage the sanguine migration, which is about the same as moderate intensity exercise.
A Finnish sauna session was found to increase heart-rate variability, which is indicative of the heart’s capacity to react strongly under stressful conditions. Long-term sauna use was also found to improve left-ventricular function and blood pressure.
Finally, men who used the sauna 4 to 7 times a week were found to have a 60% reduction in risk for Alzheimer’s and other forms of dementia.
This mimicking of the cardiovascular conditions of moderately-intense physical exercise could be a perfect standard of care for those who might be prevented from undergoing work-outs because they’ve sustained an injury.
Similarly to how the body releases cold shock proteins during cold stress, heat shock proteins are released by the body as it endures intense heat—and these can help reduce inflammation and improve muscle recovery. Perhaps because of this special mechanism, sauna bathing was also found to reduce inflammation—another important factor of recovering from long term athletic injury.
With such strong indications that frequent saunas can improve your cardiovascular health in such robust ways, doctors might want to write a new prescription for patients suffering from one of the panoply of heart diseases that strike down so many in not just America, but around the world.