By Joseph M. Kowalski, M.D.
Director of Investigational Interventions
Cardiovascular Institute of the South
A new epidemiological study suggests that the heart benefits of estrogen supplements for post menopausal women continue quite late in life.
The study by the University of Pittsburgh Medical School found a 30 percent reduction in heart disease in white women age 65 to 74 who take estrogen supplements. The findings reinforce previous government research that revealed a 25 percent reduction in heart disease among women age 45 to 64 who took estrogen supplements.
Women rarely experience heart attacks before menopause. Researchers believe that estrogen offers some protection against the blood vessel blockage that causes heart attacks and strokes. Studies suggest that estrogen increases the "good" high-density lipoprotein (HDL) and lowers the "bad" low-density lipoprotein (LDL) in the blood, thus slowing the rate at which plaque builds up in the arteries.
Another recent report that strongly suggested a connection between estrogen levels and lower rates of heart attack came out of ongoing research at Harvard Medical School. The analysis of 32,000 nurses for four years in the Nurses Cohort Study showed that those taking estrogen appeared to have one half the risk of heart attack of those not taking the hormone.
The Harvard study also showed that women who go through early menopause (before age 40) have a significantly higher risk of heart disease. The study and its findings link the ovaries and its hormones --- estrogen and progesterone --- to heart health.
According to an article in the New England Journal of Medicine co-authored by investigators at Harvard Medical School and its affiliated Brigham and Women's Hospital, "...post menopausal women who take estrogen generally have lower rates of cardiovascular disease than women of similar age who do not take estrogen."
In the 1970s, when estrogen was first prescribed as a birth control measure for women, researchers feared elevated doses of estrogen would put women at higher risk for stroke and high blood pressure. Studies in the past 35 years have not confirmed those fears. Instead, they persist in showing that estrogen supplements for post-menopausal women provide a prolongation of the natural protection from heart disease they enjoyed in their child-bearing years. Nevertheless, women enjoying the heart disease-resisting benefits of estrogen are in a minority. Only 15 to 30 percent of post-menopausal women in this country now take estrogen supplements -- in part because of concerns that it may be linked to an increase in the incidence of some cancers.