In Finland the practice of taking sauna baths dates back thousands of years and has grown in popularity in the United States over the centuries.
Scientific studies done on Finnish sauna baths have shown positive health benefits and that any possibly perceived health risks are typically unwarranted.
Effects of Finnish Sauna on the Heart
One of the health concerns thought to possibly be associated with taking sauna baths is the practice may contribute to sudden cardiac events, or heart attacks. Because it is so widely practiced there, much of the available information on sauna safety comes from Finland.
A 16-month long Helsinki study of 1,631 heart attack patients found that less than two percent had cardiac events within three hours of taking a sauna bath. A second study of 6,175 sudden cardiac related deaths that occurred over a one year period showed only 1.7 percent occurred within 24 hours of taking a sauna bath, with most of those deaths attributed to alcohol.
Canadian researchers also investigated the safety of sauna baths in 16 patients with known heart disease. Researchers compared the effects of a 15-minute sauna session with a standardized treadmill stress test. None of the participants developed abnormal heart rhythms or chest pain with either type of test.
While heart scans did show some amount of impaired blood flow to the hearts of most subjects, the impairment was milder in the sauna study group as compared to the treadmill test group.
The results from these two studies show that saunas seem not to pose a risk for you unless you have coronary artery disease that is not stable. Another small study done in Japan suggested that taking saunas daily for two weeks may even improve cardio vascular function in patients with mild hearts issues.
Taken together, these results suggest that there is no risk to you, unless you have an advanced form of coronary disease. Additionally, people who can perform moderate exercise, without resting, will likely get an okay from their physician. However, if you suffer from unstable angina, abnormal heart rhythms, poorly controlled blood pressure or advanced heart disease you should check with your doctor before taking sauna baths.
Effect of Finnish Sauna on Immune System Functioning
A limited 2013 study was performed on 18 males to investigate if a Finnish sauna bath had an effect on white blood cell profile and cortisol levels in athletes vs. non-athletes. The study evaluated nine male trained mid-distance runners as compared to nine male non-athletes.
Both groups of men participated in identical sauna bath sessions of 15 minutes followed by a two minute cool down period.
Blood samples were taken for testing immediately after the cool down period. The test showed that sauna baths resulted in an increased number of white blood cells, with higher numbers being recorded in the athlete group as compared to the non-athlete group.
These result indicated that sauna bathing can increase your immune system functioning, and to an even higher degree if you are in good physical condition.
[ https://www.degruyter.com/downloadpdf/j/hukin.2013.39.issue-1/hukin-2013-0075/hukin-2013-0075.pdf ]
[ https://www.health.harvard.edu/staying-healthy/saunas-and-your-health ]