A Finnish study found that middle-aged men may cut their risk of fatal heart attack by half.
Many Finns have saunas at home and use them as part of their regular routine. Some research suggests that the sweat-break habit may be helping them survive middle age.
Researchers recruited 2,315 middle-aged men in the mid-to-late 1980s and asked them how often they used a sauna, for how long, and the temperature. More than 20 years later, they looked at who had survived. Even after accounting for the usual factors such as smoking and exercise, the team concluded that men who used a sauna four times a week or more were more likely to be alive at the end of the 20 years than less frequent users. In fact, those who took a sauna only once a week were twice as likely to die of some kind of cardiovascular event.
Longer sessions helped, too: Compared with men who spent less than 11 minutes in the sauna, lounging for more than 19 minutes cut the risk of a cardiac-related death by half. People who spent less time in the sauna also tended to choose a lower temperature.
A Finnish sauna traditionally holds the temperature between 176 degrees and 212 degrees Fahrenheit at the level of the bather’s face, the study authors noted. Tossing water onto hot rocks temporarily increases the humidity. Dry heat has dramatic effects on the body. Skin temperature soars to about 104° F within minutes. People typically pour out a pint of sweat, and the pulse rate jumps by 30 percent or more, meaning the heart nearly doubles the amount of blood it pumps each minute. The blood is shunted away from the internal organs and goes to the skin. Blood pressure rises in some and falls in others. The effect on the heart may be much like the healthy challenge of aerobic exercise.
This study does not prove that the sauna treatments improved heart health, but is suggestive. Simply having a habit that allowed for regular relaxation, often with good company, may explain some of the effect. Men who arrange their lives in order to treat themselves to frequent saunas may have a heart-boosting self-nurturing frame of mind.
Luke Fortney, a former assistant professor of family medicine at the University of Wisconsin School of Medicine and Public Health, has prescribed sauna therapy to patients with high blood pressure, muscle spasms, seasonal affective disorder, and high stress levels. Patients who have recovered from heart attacks have enjoyed saunas safely.
In general, saunas seem to be safe for healthy people from childhood to old age, including women who are pregnant without complications. People with kidney disease, liver failure, or cardiac conditions should check first with a doctor. If you do decide to take a break in the sauna on your next trip to the gym, start with a visit under 10 minutes and make sure to drink enough fluids. Be cautious if you tend to get dizzy or lightheaded when you stand up after sitting or lying down, since a sauna might heighten the effect.
April 23, 2015
Christopher Nystuen, MD, MBA