"Silent" strokes less common in physically fit

People who participate in vigorous activity are less likely to experience "silent" strokes - strokes which, while without symptoms, leave victims more at risk of other problems in the future, a study said.

Specifically, older adults who got the most exercise — equivalent to swimming or biking more than once a week — were 40% less likely to experience such an asymptomatic stroke, said study author Joshua Willey, at Columbia University.

Even though these strokes have no symptoms, people who suffer them have a higher risk for future problems, such as trouble with walking or mental functioning, as well as more typical strokes, he added.

But the study, published in Neurology, did not prove whether physical activity actually prevents strokes, he warned, noting that people who took part in such activity might have other habits that lowered their risk.

“We know that light to moderate exercise helps with many other conditions, and we don’t want our results to discourage our patients from doing exercise,” Willey told Reuters Health.

“Any is better than none, just in general, for overall health. And it seems to be, the more the better.”

People who engaged in less physical exercise, such as vigorous activity less frequently, or low-impact exercise such as golf or bowling, were no less likely to experience silent strokes — which Willey described as a bit of a surprise.

The study, conducted by Willey and his team at Columbia and the University of Miami, interviewed more than 1200 people aged 55 and older who had no symptoms of stroke and were already participating in a study on the risk of stroke on physical activity.

They then performed brain scans to check for brain infarcts, or tissue damage due to blockage of an artery supplying that tissue.

Among the participants, who averaged 70 years of age at the time of their brain scan, 16% had experienced silent brain infarcts. Only those who engaged in the most activity had a reduced risk.

Previous studies have shown that only moderate or heavy exercise appears to ward off strokes, Willey said. He also noted that only 36% of the participants took part in light exercise, perhaps not enough to show a real impact.

Physical activity had no relationship to the risk of another silent brain event, white matter hyperintensities (WMHs), which are linked to later problems, such as dementia and trouble walking, as well as typical strokes. Their cause is unclear.

Willey noted that he and his colleagues only measured physical activity by asking people what they did over the previous two weeks, and the brain scans occurred several years after the exercise interview, which could have affected findings.

They plan to look into the relationship between brain scans and exercise in people who report their activity every year.