Regular, Vigorous Exercise May Lower Stroke Risk
Direct effect not shown in study, but experts say physical activity's impact is clear
By Randy Dotinga
THURSDAY, July 18 (HealthDay News) -- Exercising enough to break a sweat most days might slightly reduce the risk of stroke in middle-aged and older people compared to those who are inactive, a new study suggests -- although the findings aren't definitive and the difference may be insignificant.
Still, the study results indicate that "you can control your destiny with regards to stroke," said study lead author Michelle McDonnell. "A healthy diet, healthy body weight, regular exercise along with a moderate alcohol consumption and not smoking combined can reduce your risk of stroke by 80 percent. Here we show that regular physical activity is an important aspect of that and should be encouraged."
According to McDonnell, researchers already know that exercise directly reduces the risk of stroke by improving the health of blood vessels, and indirectly by improving risky traits such as high blood pressure and obesity.
The new study is unusual because it attempts to identify the effect of exercise on stroke risk and because it tracks people over time instead of relying on people's memories, said McDonnell, a lecturer in the School of Health Sciences at the University of South Australia.
The researchers tracked more than 27,000 Americans starting between 2003 and 2007 for an average of nearly six years. Many were blacks from the "Stroke Belt," an area of the southeastern United States that has an especially high stroke rate. Everyone was 45 or older at the beginning of the study, and none had previous strokes.
A total of 3.1 percent of those who said they vigorously exercised four or more times a week at the beginning of the study suffered strokes. The percentages were 3.3 for those who exercised one to three times weekly and 3.6 for those who didn't exercise, according to the study authors.
After adjusting their statistics so they wouldn't be thrown off by factors such as high or low numbers of people of certain ages, the researchers determined that those who exercised the most were 20 percent less likely to suffer strokes than those who exercised the least.