Frequent hot water bath ‘stops’ stroke

Frequent sauna bathing is associated with a reduced risk of stroke, according to a new international study. In a 15-year follow-up study, people taking a sauna four-seven times a week were 61 per cent less likely to suffer a stroke than those taking a sauna once a week.

A sauna is a small room or building designed as a place to experience dry or wet heat sessions, or an establishment with one or more of these facilities. The steam and high heat make the bathers perspire.

This is the first prospective large-scale study on this topic, and the findings were reported in Neurology.Stroke is one of the leading causes of disability worldwide, placing a heavy human and economic burden on societies. A team of scientists from the Universities of Eastern Finland, Bristol, Leicester, Atlanta, Cambridge and Innsbruck found the reduced risk associated with sauna bathing.

The findings are based on the population-based Kuopio Ischaemic Heart Disease Risk Factor (KIHD) study and involved 1,628 men and women aged 53 to 74 years living in the eastern part of Finland. Based on their frequency of taking traditional Finnish sauna baths (relative humidity 10-20 per cent), the study participants were divided into three groups: those taking a sauna once a week, those taking a sauna two-three times a week, and those taking a sauna four-seven times a week.

The more frequently saunas were taken; the lower was the risk of stroke. Compared to people taking one sauna session per week, the risk was decreased by 14 per cent among those with two-three sessions and 61 per cent among those with four-seven sessions. The association persisted even when taking into account conventional stroke risk factors, such as age, sex, diabetes, body mass index, blood lipids, alcohol consumption, physical activity and socio-economic status. The strength of association was similar in men and women.

Previous results from the KIHD study at the University of Eastern Finland have shown that frequent sauna bathing also significantly reduces the risk of cardiovascular and all-cause mortality. According to the researchers, mechanisms driving the association of sauna bathing with reduced stroke may include a reduction in blood pressure, stimulation of immune system, a positive impact on the autonomic nervous system, and an improved cardiovascular function. In a recent experimental study, the same group of scientists also showed that sauna bathing has acute effects on the stiffness of the arterial wall, hence influencing blood pressure and cardiac function parameters.