Ways to Walk Away From a Heart Attack
Regular walks could lead women away from a heart attack, researchers say.
The report gives scientific backing to a finding already demonstrated in men but only indicated in women--that even modest amounts of aerobic activity can protect the heart, the researchers say.
And it indicates that a basic level of exercise is beneficial, even though another recent study found strenuous exercise better against one heart attack risk factor, experts say.
The study focused on women who were past menopause, because this group loses the protection that the hormone estrogen has given them against heart attacks. In these women, recreational physical activity on the order of 30 minutes to 45 minutes of walking three times a week cuts the risk of heart attack by about half, the study found.
“For sure, I would say that modest activity is beneficial,” said the lead researcher, Rozenn N. Lemaitre, a research scientist at the University of Washington in Seattle. Her findings were published in the American Medical Assn. journal Archives of Internal Medicine.
Lemaitre and her colleagues looked at 268 women who had survived a first heart attack between July 1986 and the end of 1991. These women were matched with 925 women of similar age who had not suffered a heart attack.
All were members of the Group Health Cooperative of Puget Sound, a health maintenance organization, and researchers could check the women’s medical records. The researchers also called the women to ask about physical activity.
Women who had heart attacks generally reported having done less physical activity than the women who had not had heart attacks. For instance, the heart attack victims had walked on average 73 minutes a week, while the other women walked on average 101 minutes. But many in both groups were sedentary; 46% of the heart attack victims and 24% of the others reported no activities.
The researchers also divided the women into four groups, according to how much energy they were estimated to have burned while exercising. They compared the heart attack risk of the group with the least amount of exercise to the other three.
“For the three higher categories of physical activity, we had about a 50% reduction in risk, compared with women in the lowest category,” Lemaitre said.
Regular exercise walking seemed to be enough to do the job, Lemaitre said. Participation in more vigorous activities than walking did not seem to lower the heart attack risk further.
But a study that received wide media attention in the week before Lemaitre’s found a major difference among runners in one key risk factor for heart attack--HDL cholesterol. HDL is the “good” cholesterol that sweeps away fatty deposits that can lead to clogged arteries.
The study by Paul T. Williams and his colleagues at Lawrence Berkeley National Laboratory in Berkeley, looked in part at post-menopausal women. Those who were not on estrogen replacement therapy but who ran 20 to 30 miles a week had significantly higher HDL levels than those who ran less or not at all, the study said.
Women who had the additional protection of estrogen therapy gained HDL benefit from running 10 miles to 20 miles, said the study, presented in Anaheim at the American Heart Assn.'s annual meeting.
Williams and Lemaitre consider their findings complementary, not contradictory. Lemaitre did not have enough runners to draw meaningful conclusions about the additional heart attack protection from running. And Williams looked at one risk factor for heart attack, not heart attack itself.
“I don’t want to conclude that more [activity] wouldn’t help,” Lemaitre said. “But I do want to conclude that even modest activity was beneficial.”
“I have no problems with the idea that there may be health benefits for moderate activity,” Williams said. “But there may be greater benefits for extended vigorous activity.”