Moderate Exercise Can Reduce Risk for "Silent" Stroke

Keeping active may cut the risk for suffering “silent” stroke. Researchers from Columbia University and the University of Miami have found that among a group of elderly people, those who regularly participated in moderate exercise significantly lowered their risk of brain damage, certain types of dementia, and mobility difficulties associated with ischemic stroke. The new research was recently published in the journal Neurology.

The study found that people who exercised at higher levels of intensity were up to 40 percent less likely to experience brain tissue damage caused by interruption of blood flow due to artery blockage, than were those who participated in light exercise. According to study co-author Joshua Willey, a researcher at Columbia University’s Department of Neurology, “It’s not good enough just to exercise, but the more (intense) the better.”

The findings suggest that vigorous exercise performed on a regular basis may be the best method for stroke prevention. Willey explained, “We think exercise is protecting against the development of brain infarcts, and the hope is with lower risk of having these events, you'd also be at lower risk of dementia or stroke.” Although previous studies have shown that exercise aids in the prevention of stroke by reducing risk factors such as high blood pressure, bad cholesterol, and elevated insulin levels, brain damage resulting from having suffered multiple “silent” strokes is permanent.

The study began in 1993, and involved members of the Northern Manhattan Study cohort that eventually reached 3,298 people over the age of 55. The focus of the analysis was on risk factors for stroke and other vascular conditions. Each study participant was asked to complete a questionnaire about the frequency and intensity of their exercise. Some six years after the beginning of the study, at an average of 70 years old, the study subjects underwent an MRI scan of their brains.

Results of the questionnaires showed that 43 percent of participants had no exercise routine, while 36 percent regularly performed light exercise, including such activities as golf, walking, bowling or dancing. Another 21 percent reported that they regularly exercised from moderately to intensely, participating in such activities as hiking, tennis, swimming, biking, jogging or racquetball. Findings of the analysis showed that the risk of small brain infarcts was lower by about 40 percent among those who reported high levels of physical activity. However, no difference was noted for those who engaged in light exercise, and those who did not exercise.

Although the study did not focus on the reasons why intense exercise is apparently so healthful, Willey noted, “Some of the effects of exercise appear to be related to improving other health conditions that affect the risk of stroke, such as hypertension, obesity, high cholesterol and low HDL, diabetes, atherosclerosis (hardening of the arteries) and heart disease.”

The researchers pointed out that engaging in exercise, whether light, moderate or vigorous, can still go a long way to improve and protect health. Willey acknowledged, “We did not want this to discourage anyone from exercising, even if it’s light exercise. The benefits of exercise are proven. We feel that's an integral part of general good health.” The American Heart Association recommends 150 minutes of moderate-intensity, or 75 minutes of vigorous-intensity exercise weekly, to maintain cardiovascular health.