By Matt McMillen
WEDNESDAY, June 8, 2011 (Health.com) – Small strokes that do not cause outward symptoms but may have serious long-term consequences can be controlled by vigorous exercise such as jogging and cycling , a new study in the journal Neurology suggests.
Walking and other light-weight exercises, on the other hand, seem to offer no protection against these so-called silent strokes, which cause small brain lesions and are associated with an increased risk of falls, memory problems, dementia, and full-blown strokes.
"The more reasons we can tell our geriatric patients to exercise, the better," says lead author of the study, Joshua Z. Willey, MD, assistant professor of neurology at Columbia University Medical Center, New York City. "[exercise] not only prevents strokes and heart disease, it also prevents these markers associated with other diseases, including dementia, and total mortality."
The study included 1
Each of the participants answered questions about their practice habits, including the activities he participated in as often and for how long. Forty-three percent of the participants had no movement at all; 36% were involved in light training sessions such as walking, golfing or bowling; and 21% stated that they received regular, moderate to vigorous exercise through cycling, swimming, racquetball and similarly intense activities.
Approximately six years later, participants were each undergoing MRI to look for signs of silent strokes, also known as subclinical brain infarctions. About one in six patients had lesions consistent with a silent stroke.
The probability of having a silent stroke was 40% lower in the heavy exercise group than in the sedentary group. However, the light athletes were as likely to have lesions as those who did not exercise at all, even if the researchers considered other risk factors (such as cholesterol, blood pressure and diabetes).
t means that a low-intensity exercise has no value. Like Dr. Willey and his co-authors quickly discover that having light physical activity has other health benefits. It is also possible that in a larger study population, they found a subtle but measurable link between low-intensity exercise and a lower risk of a silent stroke.
"Perhaps it was simply because they could not measure a difference," says Helmi Lutsep, MD, stroke expert and deputy neurology professor at Oregon Health and Science University, Portland.
But the results reflect similar research on movement and (non-silent) strokes. Previous studies, including a study by Dr. med. Willey's team, which includes researchers at Columbia and the University of Miami, has linked consistent movement – but no easy movement – to a lower risk of stroke.
Dr. Lutsep, who was not involved in the study, says that some of her older patients have difficulty moving regularly. She often advises these people to include brief bursts of intense activity in their exercise routine.
"Even if they can not sustain intense activity, they can often make their exercise a little stronger for a short time, say 10 minutes," she says.
One of the study results surprised Dr. Willey: Uninsured participants as well as Medicaid patients did not see a reduction in the risk of dulling, no matter how strong they were. Although he can not explain why, he suspects that these participants have basic medical problems that are not adequately treated.
Dr. Lutsep agrees. "If we have a patient who is not insured, he probably will not take any blood pressure medicines to help prevent strokes," she says. "The risks are increased."