Saunas may do more than make you sweat; a new study from the University of Eastern Finland suggests that regular sauna bathing is good for the mind as well.

The effects of sauna bathing on the risk of Alzheimer’s disease and other forms of dementia were studied in the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD). The 20-year study followed more than 2,000 middle-aged men (aged 42 to 60 years) living in Finland.

Based on their sauna-bathing habits, the study participants were divided into three groups: those taking a sauna once a week, those taking a sauna 2-3 times a week, and those taking a sauna 4-7 times a week.

Strikingly, the more frequently saunas were taken, the lower the risk of dementia was. And lower by significant margins: among those taking a sauna 4-7 times a week, the risk of any form of dementia was 66 per cent lower, and the risk of Alzheimer’s disease 65 per cent lower than among those taking a sauna just once a week. The study’s findings were published recently in the Age and Ageing journal.

The association between sauna bathing and dementia risk has not been previously investigated, but previous results from the KIHD study have shown that frequent sauna bathing also significantly reduces the risk of sudden cardiac death and the risk of death due to coronary artery disease and other cardiac events. That study also found a correlation between the number of saunas taken and a decreased risk of the health issues studied.

Rita Redberg, MD, of the University of California, San Francisco, and editor-in-chief of JAMA Internal Medicine, says: “Although we don’t know why the men who took saunas more frequently had greater longevity (whether it is the time spent in the hot room, the relaxation time, the leisure of a life that allows for more relaxation time or the camaraderie of the sauna), clearly time spent in the sauna is time well spent.”

According to Professor Jari Laukkanen, the study’s leader, it’s possible sauna bathing may protect both the heart and memory to some extent via similar, but still poorly understood mechanisms. “However, it is known that cardiovascular health affects the brain as well,” Laukkanen says. “The sense of wellbeing and relaxation experienced during sauna bathing may also play a role.”