A study of 73,029 women found that those who were most active had about a 40 percent lower risk of heart attacks and strokes than the least active, and even modest activity produced significant drops in risk.
“There are very limited data in women” about the value of exercise, said Dr. JoAnn E. Manson, the study’s director and co-director of women’s health at the Brigham and Women’s Hospital and Harvard Medical School. “This study suggests exercise has comparable benefits in men and women.”
In a separate study, Dr. Charles B. Eaton of Brown University found that men who reported any leisure-time physical activity at all had a 21 percent lower risk of death from heart disease than did sedentary men.
The most vigorous exercisers had only a slightly greater advantage - a 29 percent lower risk than the sedentary men - suggesting that “most of the benefit occurred with light activity, not even on a daily basis,” said Eaton, who directs the heart disease prevention program at Memorial Hospital of Rhode Island in Pawtucket.
Both studies were presented at the American Heart Association’s annual epidemiology meeting, which ended Saturday.
In a third study also reported at the meeting, researchers found that physical activity reduces the risk of heart attack in postmenopausal women by as much as 60 percent.
Manson said the studies “all have the same message” - physical activity cuts the risk in men and in women, and even modest amounts are enough to make a difference.
Manson said she knew of only about six studies looking at how physical activity can benefit women’s hearts. Her study, part of a continuing examination of nurses who were originally asked about exercise habits in 1986, found that physical activity in women helps prevent high blood pressure, diabetes, obesity and stress.
She found that the heart attack rate of about 150 per year for every 100,000 sedentary women fell to about 84, a 44 percent drop, in the most active women. The rate of strokes fell 42 percent, from about 90 per 100,000 sedentary women to about 52.
The benefits were greater the more women exercised, but they were substantial even in women who engaged in only modest physical activity, she found.
In a study of 8,463 Israeli men who were followed for 21 years, Eaton found benefits in men who engaged in “light activity on a less than daily basis.” He found that light activity had almost as much benefit as moderate exercise.
He also found that exercise reduces the overall death rate, not just the death rate from heart disease.