Older adults who do at least regular moderate exercise may reduce the risk of silent strokes, according to a new study.
So-called silent strokes are not going to kill you or leave you partially paralyzed. But they do damage the brain. Like many major strokes, silent strokes happen when a blood clot prevents blood from reaching a region of the brain.
The result can be seen on an MRI brain scan, but Columbia University researcher Joshua Willey says they often don't have obvious symptoms.
"And we distinguish these from what we call clinically overt or clinically apparent strokes," he says. "And what usually we see is an area of damage in the brain that's usually small - in the millimeters range in size - and usually in the deeper structures of the brain."
Silent strokes can put the patient at risk for future problems, including falls and dementia.
Willey and his colleagues studied the effect of regular exercise on the chance of suffering a silent stroke. They interviewed about 1,200 older adults about their exercise habits. Then, six years later on average, they had MRI scans of their brains.
"We found that those who engage in the highest total amount of physical activity had almost about a 40 percent lower chance of having these silent strokes," Willey says.
There was less of an effect for the men and women who exercised less. Those in the lowest intensity exercise group - those who walk, typically - did no better than those who never exercised.
Willey says more and harder exercise is better, but even light exercise like walking has benefits, even if it does not appear to reduce the risk of this kind of stroke.
"We do not want our findings to discourage folks from doing exercise, because we know that even light intensity activity has several protective effects against other diseases as well."
Interestingly, there was no apparent exercise benefit for people who did not have any health insurance, or who were on the Medicaid program for very poor Americans. Willey suspects that may be because poor or lower class people, who tend to not have insurance or easy access to medical care, are more likely to be unhealthier in general.