By Dr Luisa Dillner/London
Saunas usually have signs warning against their use by pregnant women, children and anyone with a heart condition. Yet in Finland, where there are 1.6mn saunas for a population of 5mn, children often try them in infancy and almost everyone has at least one a week.
Last week, a study in JAMA Internal Medicine of 2,315 middle-aged men, who had been assessed for more than 20 years, concluded that saunas reduced the risk of dying from heart disease by up to 50%, and the risk of a sudden death (defined as within an hour of an acute change in symptoms) by up to 63%.
The researchers allowed for factors such as existing heart disease, age (the average was 53), blood pressure, smoking and anything else that might increase risk.
Not surprisingly, the research was done in Finland. One of its authors, Dr Lari Laukkanen, said that the benefits of saunas outweighed any risks and that the more frequently people had them in the study (four to seven times a week), the more they seemed to be protected from heart disease. He says he is always surprised by health warnings in countries outside Finland, as in his opinion saunas are safe for most people except those with unstable angina, a recent heart attack or a narrowing of their aortic valve – or if you feel unwell.
People with stable heart disease should be OK, according to the research. Deaths in saunas are rare and usually associated with alcohol – people get hyperthermia because they’re too drunk to realise how hot they are. So is this enough for you to do as they do in Finland, and build one on to your house?
There is evidence that saunas are good for you, but this particular study was done only on men in Finland where saunas are dry and kept at 80 to 100C at the level of the bather’s face. The results wouldn’t necessarily be the same in women in other places.
But there is evidence that regular exposure to saunas increases the output of the heart, lowers blood pressure, improves tolerance to heat and may also improve breathing by increasing (among other things) the vital capacity – the maximum amount of air a person can exhale.
In Finland, pregnant women use saunas and there seems to be no increase in birth abnormalities, with it considered safe for all but high-risk pregnancies. Healthy Finnish children over the age of five cope with shorter sessions (five minutes) sitting on the lower, cooler benches. Saunas may also alleviate pain in rheumatological conditions.
Sensible use is likely to do more good than harm but sweating heavily can make you feel faint so do get up slowly when leaving a sauna. - Guardian News and Media
-Dr Luisa Dillner, a writer and doctor, heads BMJ Group Research and Development.
