Image: A new study suggests that regular sauna bathing can reduce the risk of men developing hypertension by up to 46% (Photo courtesy of iStock).
Researchers at the University of Eastern Finland (Joensuu, Finland), the University of Leicester (United Kingdom), and other institutions conducted a study involving 1,621 men (42-60 years of age) without hypertension to assess the relationship between sauna bathing and risk of incident hypertension. Sauna bathing frequency was based on questionnaires, with hypertension defined as a physician diagnosis, systolic blood pressure (SBP) higher than 140 mm Hg, diastolic blood pressure higher than 90 mm Hg, or use of antihypertensive medication. During follow-up, 251 men developed high blood pressure.
The results revealed that compared with men who had one sauna bathing session per week, those who had two to three weekly sessions had a 24% lower risk of developing high blood pressure, and men who had four to seven sauna sessions weekly had a hypertension risk that was 46% lower. The researchers suggest that the increase in body temperature during sauna bathing can cause blood vessels to dilate, increasing blood flow. Regular saunas can also increase endothelium function, which can also improve blood pressure. The study was published on June 13, 2017, in the American Journal of Hypertension.
“During sauna bathing, the body temperature may rise up to two degrees Celsius, causing vessels’ vasodilation, which decreases blood pressure,” said lead author Francesco Zaccardi, MD, of the Diabetes Research Centre at the University of Leicester. “In addition, those taking a sauna frequently may also have a lower risk of pulmonary diseases, lung diseases that block airflow and make it difficult to breathe.”
The Finnish sauna is a substantial part of Finnish culture, with five million inhabitants and over three million saunas, an average of one per household. The sauna steam room is typically heated to 80-110 °C; water is thrown on hot stones topping the kiuas, a special stove used to warm the sauna which produces large amounts of wet steam, known as löyly, increasing the moisture and the heat within the sauna. When the heat begins to feel uncomfortable it is customary to jump into a lake, sea, roll in the snow, or even swim in a hole cut in lake ice.
University of Eastern Finland
University of Leicester