Frequent use of a sauna can help keep you from developing high blood pressure, one of the most important risk factors for heart disease. Researchers from the University of Eastern Finland found that the risk was almost halved in men who had a sauna at least four times a week when compared to those who only had one sauna a week.

Saunas are small rooms which provide either moist or dry heat and allow the body to sweat deeply. The use of dry saunas goes back thousands of years in Finland, where almost a third of adults enjoy them on a regular basis.

The Kuopio Ischemic Heart Disease Risk Factor Study (KIHD) involved 1,621 middle-aged men living in the eastern part of Finland. Study participants included men without elevated blood pressure, or with diagnosed hypertension (140/90 mmHg or higher) at the beginning of the long-term study.  

Based on their sauna bathing habits, men were divided into three sauna frequency groups: those taking a sauna once a week, 2-3 times a week, or 4-7 times a week.

During an average follow-up of 22 years, 15.5 percent of the men developed clinically defined hypertension. The risk of hypertension was 24 percent lower among men with a sauna frequency of 2-3 times a week, and 46 percent lower among men who had a sauna 4-7 times a week.

Researchers speculate that several biological mechanisms may be involved in the lowering of blood pressure:

• During sauna bathing, the body temperature may rise about three degrees, which causes vessels to dilate.

• Regular sauna bathing aids endothelial — the inner lining of blood vessels — function, which improves blood pressure.

• Sweating removes fluid from the body, which also contributes to decreased blood pressure.

• Sauna bathing may also lower blood pressure due to relaxation of both mind and body.

The study's results were published in the American Journal of Hypertension.