Taking saunas may reduce the risk for stroke.

Researchers studied 1,628 men and women ages 53 to 74, free of stroke at the start. They had data on body mass index, alcohol consumption, smoking, blood pressure and other health and behavioral characteristics that affect cardiovascular health.

The participants reported how often they took traditional Finnish saunas and how long they stayed in the sauna, and the researchers followed them for an average of 15 years. There were 155 strokes over the period. The study is in the journal Neurology.

After adjusting for other variables, they found that compared with people who took saunas once a week, those who took them two to three times weekly were 12 percent less likely to have a stroke. People who took saunas four to seven times a week cut their risk for stroke by 62 percent.

The study was observational and cannot prove causality. Still, there are plausible reasons saunas might be protective.

“Temperature increases, even of 1 or 2 degrees Celsius, can limit inflammatory processes in the body and reduce arterial stiffness,” said the senior author, Dr. Jari A. Laukkanen, a professor of medicine at the University of Eastern Finland. “It’s possible that steam rooms or hot tubs could produce similar results.”

POLLUTION RISKS FOR THE YOUNGEST

Air pollution, even of short duration, increases the number of lower respiratory infections, a new study reports, and the effects may be particularly serious in young children.

Acute respiratory infection of the lungs and airways, usually caused by viruses, are a leading cause of illness and death in young children.

The study, in the American Journal of Respiratory and Critical Care Medicine, tracked 146,397 people, 77 percent of them children younger than 2, who had infections treated in hospitals and clinics in Utah. Researchers gathered data on levels of small particulate matter, or PM2.5, from sensors at three monitoring stations in the state’s Wasatch Front region. The area has substantial variations in PM2.5.

Beginning in the second week after an increase in pollution levels, the researchers found a corresponding increase in respiratory infections, peaking in the third week after the PM2.5 increase.

The scientists calculate that each short-term increase of 10 micrograms per cubic meter in PM2.5 is associated with a 15 to 23 percent increase in serious respiratory infections.

“There’s no reason to panic here,” said the lead author, Benjamin D. Horne of Intermountain Medical Center Heart Institute. “When air pollution is high, avoid idling cars, stay distant from highways, stay indoors or go out in the early morning when pollution is usually lower. We don’t have to feel like we’re victims.”

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