In Eastern Finland, a study cohort put together in the 1980’s consisting of a few thousand men and women would be examined by scientists over a period of 3 decades or so for a variety of common disease risks such as cardiovascular disease, coronary heart disease, stroke, and all-cause mortality.
This cohort known as the Kuopio Ischemic Heart Disease Risk Factor Study, was examined for these diseases because of their frequent use of sauna bathing as a leisure activity and perhaps unknowingly, a lifestyle intervention.
Fast forward to just a few years ago and a paper was published demonstrating the dose-dependant 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. Men for instance who used the sauna 2-3 times a week for about 15 – 20 minutes had an 18% reduction in the risk of fatal coronary heart disease, but those who went 4-7 times a week had a 20% further risk reduction.
Further studies came out, investigating stroke and hypertension which also found dose-dependant effects on the benefits of sauna use.
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 with 10% – 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 the diseases mentioned earlier 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 – about the same as moderate intensity exercise.
A Finnish sauna session was found to increase heart-rate variability, indicative of the heart’s capacity to react strongly to stressful conditions. Long-term sauna use was also found to improve left-ventricular function and blood pressure.
Finally, men who used the sauna 4-7 times a week were found to have a 60% reduction in risk for Alzheimer’s and other forms of dementia.
This replication of the cardiovascular conditions of moderately-intense physical exercise could be key for standard of care treatment for patients suffering from cardiovascular and coronary heart diseases, but also represents a method of mimicking exercise one might be prevented from doing if they’ve sustained an injury.
Similar to cold shock proteins released by the body during cold stress, heat shock proteins, released by the body as it endures intense heat help to 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.
A truly remarkable culmination of 30 years of research, the strong indications that frequent sauna bathing can improve your cardiovascular health in such robust ways mean it could very well be added to the standard of care treatment for patients suffering from one of the panoply of heart-diseases that strike down so many in not just America, but across the face of the earth.