There's such a thing as healthy heat
With the sky dark after your early morning or evening swim and cold weather waiting to greet you the second you step outside the facility, taking a few moments in the sauna could be a great way to boost your mood and warm up.
But growing evidence suggests sauna bathing may do more than just make us feel good, according to Jari Laukkanen, a researcher in sport and health sciences at the University of Jyväskylä in Finland and the lead author of an in-depth literature review published in Mayo Clinic Proceedings in 2018. “Accumulating evidence suggests that regular sauna bathing may alleviate and prevent the risk of both acute and chronic disease conditions,” Laukkanen and his colleagues wrote.
These include heart-related conditions such as high blood pressure and cardiovascular disease, brain problems such as stroke and neurocognitive disease, and a wide miscellany of other miseries ranging from arthritis and headaches to asthma and the flu.
In one study of sauna bathing’s impact on blood pressure, for instance, investigators recruited 1,621 men aged 40–62 and followed them for 24.7 years. Frequent sauna users, who averaged four to seven sessions a week, were 47 percent less likely to develop hypertension compared to infrequent users. Other work conducted by Laukkanen followed 2,315 Finnish men for 20.7 years. This showed that the higher the frequency and duration of sauna bathing, the greater the reduction in risk for sudden cardiac death, fatal coronary heart disease, and all-cause mortality.
Still, other investigators have studied sauna bathing and neurocognitive disease. A prospective cohort study, for instance, of 2,315 healthy Finns aged 42–60 at baseline showed that compared to once-weekly sauna bathers, those averaging four to seven sessions per week had a reduction of risk for dementia and Alzheimer’s of 66 and 65 percent, respectively.
“There is also evidence that sauna exposure could boost the immune system,” Laukkanen wrote, “which may partly explain why sauna baths reduce susceptibility to common colds and prevent infections in healthy individuals.”
Association, of course, does not necessarily imply causation, and frequent sauna bathers may owe their reduced risk to other, unrelated health behaviors (such as pre-sauna workouts). Still, a multitude of plausible mechanisms suggest that heat exposure by itself can tweak our physiology in beneficial ways, Laukkanen says.
Regularly dilating peripheral blood vessels, for instance, may enhance so-called endothelial function, making our arteries more elastic and compliant. Heat exposure also seems to reduce oxidative stress and inflammation while favorably modulating the autonomic nervous system (i.e., the part controlling unconscious actions such as breathing, heartbeat, and digestion).
Such smoking guns will require more research to confirm, but as far as the big picture goes, it appears sauna bathing shares much in common with actual physical exercise.
“The responses produced by an ordinary sauna bath correspond to those produced by moderate- or high-intensity physical activity such as walking,” Laukkanen and his colleagues wrote. Think of it as a way to get a workout without actually having to move a muscle.
As for those who like to exercise actively before passively (capping off, say, a vigorous workout with 20 to 30 minutes in the sauna), the combination appears even better for heart health. The Mayo Clinic Proceedings review pegged two recent studies that have found that being highly fit and a frequent sauna bather is associated with an even greater reduction of cardiovascular risks than either activity alone.
Laukkanen believes that pretty much anyone can benefit. “It is a safe activity and can even be used in people with stable [coronary vascular disease], provided it is used sensibly for an appropriate period of time,” he and his colleagues wrote.
There are, of course, more ways to experience these benefits than by going to a sauna, which refers to both the hot-air bathing experience and the chamber in which it takes place. The Finns invented saunas more than 2,000 years ago and first reached our shores from Finnish immigrants in Delaware in 1638, but many cultures have variations of therapeutic body heating, from the spiritual sweat lodges of Native Americans to the thermae of Ancient Rome that began today’s Turkish baths. Add to these all sorts of modern methodologies: hot tubs, steam baths, and even so-called “infrared saunas” that warm your skin without impacting the ambient air.
But be sure to check with your doctor if you have any health problems or take medications that could interfere with your body’s heat regulation.
- Health and Nutrition