Women and Heart Disease : Part 3

by Food and Drug Administration (FDA)

(Page 3 of 3)

Prevention Tactics Vary

The tricks of the trade for preventing coronary heart disease also vary from men to women. Post-menopausal women may have the option of possibly delaying or preventing the onset of heart disease by taking daily estrogen, in a dose comparable to what their bodies generated before menopause. Some studies suggest that women who take estrogen during and after menopause have about half the risk of heart attack as women who don't take the hormone. Natural production of estrogen before menopause, some researchers speculate, may explain why women develop heart disease later than men.

Whether estrogen replacement therapy may help delay or prevent heart disease in women, however, remains unproven. Since women selected for estrogen treatment in studies were often healthier, slimmer, and more active than those who didn't receive the hormone therapy, their reduced heart attack risk could have been due to lifestyle characteristics rather than by the estrogen treatment. Because of these uncertainties, FDA has not approved the use of estrogen for prevention of cardiovascular disease.

Use of estrogen after menopause is linked to a greater risk of developing endometrial cancer. To counter that risk, estrogen is often prescribed with the hormone progestin.

Whether this hormone combination also prevents heart disease in women is also unknown. To resolve this question and to prove whether estrogen replacement therapy prevents heart disease in women, the National Institutes of Health has undertaken a randomized clinical trial as part of the Women's Health Initiative. Results are not expected to be available for five to 10 years, however.

A mainstay in treating and preventing heart disease in men is a diet low in cholesterol, a fat-like substance carried in the blood and used by the body to build cell walls, sex hormones, and a variety of other vital substances. When too much cholesterol accumulates in the blood, it clogs arteries.

The amount of the two main types of cholesterol found in the blood, however, is key to pinpointing heart disease risk. Cholesterol carried by low-density lipoproteins (LDLs) is more likely to be deposited on artery walls, unlike cholesterol carried by high-density lipoproteins (HDLs), which often is ferried back to the liver where it is processed or removed. High levels of HDL cholesterol and low levels of LDL cholesterol are linked to lower risk of heart disease in both men and women. But HDL levels are a much more powerful predictor of heart disease risk in women than LDL levels, several studies suggest.

A low-cholesterol, low-saturated-fat diet can lower blood cholesterol by more than 15 percent in men. Epidemiological studies of men also found that each 1 percent drop in blood cholesterol was accompanied by a 2 percent drop in the risk of a heart attack.

Research suggests high cholesterol is a risk factor for heart disease in women, too, but experts debate whether women should strive to lower their cholesterol to the levels recommended by the American Heart Association because these levels are based on studies done primarily in men.

A cholesterol-lowering diet in women not only lowers LDL cholesterol, but nearly equally lowers their HDL cholesterol, pointed out John Crouse, M.D., of the Bowman Gray Medical School in North Carolina. Because high HDL levels are so much more protective in women than low LDL levels, lowering total cholesterol may not benefit women and may do more harm than good, he claims. The National Heart, Lung, and Blood Institute is conducting several studies to assess if this is the case.

Like men, however, women can help prevent heart disease by using medications or other measures to stem high blood pressure, losing weight if they are overweight, and not smoking. Both sexes should adhere to a low-fat diet and not consume alcohol if they have high blood levels of triglycerides, a type of fat produced by the liver when alcohol is drunk or when excess calories are taken in.

Scientists are studying whether vitamin E and the vitamin A precursor beta carotene may also help stave off heart disease. Women with a high vitamin E consumption had a 34 percent lower risk of heart disease, according to an epidemiological study by Meir Stampfer, M.D., of Brigham and Women's Hospital in Boston. In the same study of more than 87,000 nurses, those with boosted beta carotene consumption had a 22 percent lower risk of heart disease.

Vigorous aerobic exercise is often touted as a heart disease preventive. But regular walking may be equally effective, according to a small epidemiological study at the Cooper Institute for Aerobics Research in Dallas. Women who walked three miles a day, five days a week decreased their risk of heart disease, even if they took 20 minutes to walk a mile.

Much more research needs to be done, however, to paint a complete and accurate picture of the best ways to prevent, diagnose and treat heart disease in women. "It's only been about five years," noted Wenger, "that we've begun to carefully look at heart disease in women, in contrast to 30 years experience looking at it in men — we have a lot of catching up to do."

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