A study from Finland published in 2016 did show that the more saunas men took per week, the lower their risk of dementia. (Women weren’t included in the study.) Here’s the story: the men were between the ages of 42 to 60 when they joined a study of heart disease. Researchers from the University of Eastern Finland and the University of Bristol in the U.K. followed the men for almost 21 years to determine whether saunas are associated with the risk of dementia and Alzheimer’s disease. They found that men who used saunas an average of four to seven times per week were 66 percent less likely to develop dementia and 65 percent less likely to develop Alzheimer’s disease. In comparison, men who used saunas only once a week were 22 percent less likely to develop dementia and 20 percent less likely to develop Alzheimer’s than men who didn’t use saunas at all. The researchers reached these conclusions after controlling for risk factors such as age, alcohol consumption, body mass index, systolic blood pressure, smoking, diabetes, previous heart attack, resting heart rate, and LDL cholesterol.
Study leader Jari Antero Laukkanen said the findings were surprisingly strong. The researchers wrote that taking saunas “may be a recommendable intervention” to prevent dementia and Alzheimer’s disease in healthy adults but noted that more studies are needed to see if the results hold true for women and other patient populations.
The same researchers had previously investigated whether saunas helped lower the risk of cardiovascular events among the men in the study. They reported that those who used saunas two to three times a week had significantly lower rates of sudden cardiac death, fatal cardiovascular disease and all other causes of death over a period of 18 years compared to men who used saunas only once a week.
All of the study participants used traditional Finnish saunas, which begin with dry air and a recommended temperature of 80 to 100 degrees Centigrade. Humidity is then increased by throwing water on the hot rocks of the sauna heater.
The investigators noted that recent research has suggested that inflammation and oxidative stress may contribute to the development of dementia. They added that their findings are “biologically plausible,” as regular saunas reduce inflammation by improving vascular endothelial function. (The endothelium is the thin membrane lining the blood vessels.)
I’m a sauna enthusiast and welcome this study’s positive findings. However, if you have high blood pressure or a heart problem, be sure to check with your physician before taking one. The heat can cause circulatory changes, including an increased heart rate. Overall, if you’re healthy, the only real risk of a sauna is spending too much time sweating. You can faint from overheating and from dehydration. Be sure to drink lots of water before, during and after your time in the sauna room.
Andrew Weil, M.D.
Jari Antero Laukkanen et al, “Sauna bathing is inversely associated with dementia and Alzheimer’s disease in middle-aged Finnish men.” Age & Aging, March 1, 2017, doi: 10.1093/ageing/afw21