Help for Hot Flashes
Is soy the solution to this menopausal symptom?
Heating Up the Soy Debate
In Asian countries where soy is a dietary staple, women tend to get fewer hot flashes than women in the U.S. But when studies have looked closely at soy's effects on menopausal symptoms, the results have been mixed.
"I'm a strong proponent of soy, and think that menopausal women should be incorporating soy into their diet," says Mark Messina, PhD, MS, an adjunct professor of nutrition at Loma Linda University in Loma Linda, Calif. "But I'm not basing that recommendation solely on its effects on hot flashes."
One of the studies most strongly supporting soy foods, says Messina, was research from Italy published in 1998, which found a 45% reduction in hot flashes in women consuming soy protein, compared to a 30% improvement in the placebo group. But for every positive study, he adds, there has been another showing no soy-related benefits.
In research published in March 2002 in the journal Obstetrics & Gynecology, menopausal women took a daily dose of 100 mg of soy isoflavones (an estrogen-like constituent of soy that appears to be the key ingredient easing hot flashes). These women experienced a significant decline in their menopausal symptoms, including hot flashes, mood swings, and sleep difficulties. But in another study in 2002 at Tufts University, researchers found that after three months of soy supplementation, women had no more relief from hot flashes than another group taking a placebo (dummy) pill.
In the heat of the debate, doctors like Machelle Seibel, MD, remain persuaded by the positive findings, and urge women to give soy a try. "There is some good data that soy can reduce both the frequency and the intensity of hot flashes by about 50%," says Seibel, professor of clinical obstetrics and gynecology at the University of Massachusetts Medical School in Worcester. "A lot of doctors feel that somehow that's not significant enough, and would prefer that it eliminate all hot flashes. But if it can reduce hot flashes sufficiently enough so a woman can get a good night's sleep, that may allow her to cope better."