NEW YORK, Oct 19 (Reuters Health) -- One hour of brisk walking everyday can cut a woman's risk of developing type 2 diabetes in half, according to a report in the October 20th issue of The Journal of the American Medical Association (JAMA).
One hour per day of walking, or another form of moderately intense physical activity such as doing housework, can substantially reduce diabetes risk, similar to the reduction in diabetes risk linked to more vigorous exercise, such as running or jogging, report researchers.
Type 2 diabetes, also known as non-insulin dependent diabetes, is strongly associated with obesity. Losing weight is usually the first step in treating the disease.
"Our findings lend additional support to current guidelines from the Centers for Disease Control and Prevention and the National Institutes of Health that recommend that Americans should accumulate at least 30 minutes of moderate-intensity physical activity on most, preferably all, days of the week," write the team, led by Dr. Frank B. Hu of the Harvard School of Public Health in Boston, Massachusetts.
In the study, the investigators evaluated responses to questions about the intensity and duration of physical activity provided in 1986 by roughly 70,000 women participating in the Nurses Health Study. The women were free of heart disease, diabetes, and cancer at the time they answered the questions. During 8 years of follow-up, 1,419 women developed diabetes.
After taking into account known risk factors for diabetes, a relationship between physical activity and the risk of type 2 diabetes emerged. "Increasing physical activity substantially reduced the risk of type 2 diabetes," Hu said in a telephone interview with Reuters Health. "What is particularly interesting," he said, "is that the risk reduction for moderate intensity activity such as walking is the same as that for more vigorous forms of activity such as running or jogging, if the energy expenditure is the same. Total energy expenditure is most important (factor)."
The finding that moderate exercise such as walking reduces the risk of diabetes just as more vigorous exercise does is "reassuring," Hu and colleagues write in the JAMA paper. "Walking is a physical activity that is highly accessible, readily adopted and rarely associated with physical activity-related injury," they note.
Obesity and a sedentary lifestyle are major risk factors for type 2 diabetes, Hu told Reuters Health. Physical activity can reduce the risk of type 2 diabetes through weight reduction and by helping the body use the hormone insulin more efficiently, he said.
It appears from this study, Hu added, that "it doesn't matter how you (expend energy) as long as you do."
