Can walking help guard against stroke?
Reported April 21, 2010
NEW YORK (Reuters Health) - Walking may be an important weapon for
women in the fight against stroke, a new study hints.
The study found that women who walked for two or more hours a week had a
lower risk of stroke than those who walked for less than two hours a week.
It's well known that physical activity is good for heart health, including
reducing the risk of stroke. "More active people generally demonstrate a 25
to 30 percent lower risk of stroke," Jacob Sattelmair, the study's lead
researcher and a doctoral candidate in epidemiology at Harvard School of
Public Health in Boston noted in a telephone interview with Reuters Health.
To investigate further, Sattelmair's team studied more than 39,000 healthy
women aged 45 or older enrolled in the Women's Health Study. The women
reported their leisure-time physical activity at the start of the study
(1992-1995) and periodically during the study.
During an average follow-up of nearly 12 years, 579 women suffered a stroke.
There were 473 ischemic strokes - the most common type caused by a blockage
or blood clot supplying blood to the brain -- and 102 hemorrhagic, or
"bleeding," strokes. Four strokes were of an undetermined type.
Overall, the most active women in the study were 17 percent less apt to
suffer a stroke during follow up than the least active women, the
Compared with women who didn't walk, women who walked two or more hours a
week at any pace cut their risk of any type of stroke by 30 percent.
Women who walked at a pace of 3 miles per hour or faster had a 37 percent
lower risk of suffering any type of stroke compared to those who walked at a
slower pace. Walking appeared to primarily lower the risk of ischemic
These observations "certainly add to the evidence that even
moderate-intensity activity such as brisk walking is beneficial to the
reduction of risk of strokes," Dr. Frank Hu, of the Harvard School of Public
Health, who was not involved in the study, told Reuters Health by phone.
Hu published a study in 2000 in the Journal of the American Medical
Association showing that physical activity, including walking, provided a
significant reduction in stroke risk.
The current study is "observational," Hu pointed out, with self-reported
data. But the research team controlled well for other risk factors for
stroke, he said, such as smoking. A connection between more vigorous forms
of physical activity and reduced stroke risk couldn't be properly examined
in the study, he added, because there weren't a sufficient number of
vigorous exercisers; walking was a more popular activity for the study
Sattelmair and colleagues note that their study primarily looked at
well-educated, middle-aged white women, although there is no particular
reason to believe that the results can't be generalized across the wider
population of American women, according to the researchers.
Men were also not included in the study; exercise has generally been shown
to reduce stroke risk in men as well, but there isn't yet clear data on how
walking specifically affects risk for them.
Hu said this study is clinically important because of the devastating side
effects of stroke, which include reduced mobility, speech difficulties and
memory loss. Stroke is the third leading cause of death in the United
States, after heart disease and cancer.
"The bottom line," Hu said, "is that this study provides another piece of
evidence for why people should move and get off the couch."
SOURCE: Stroke: The Journal of the American Heart Association, online
April 6, 2010.