The standard treatment for menopause and its symptoms is hormone replacement therapy, using estrogen or a combination of estrogen and progestin. But each has associated cancer risks. Last year, a major study found a substantial increase in a woman's risk for breast cancer if she took hormones, estrogen and progestin, for several years. The study, published in the Journal of the American Medical Association, found for each year of therapy, a woman's risk of breast cancer increased 8 percent, compared to a 1 percent increase in women taking estrogen only. But estrogen-only treatment is no panacea, either.
Some studies link it to an increased risk of uterine cancer.
So here's where soy supposedly comes in for the rescue. Soy, from the soybean plant, contains substances known as isoflavones. These isoflavones are phytoestrogens, a plant substance that acts like a weak form of estrogen on the body. That is, they can inhibit and stimulate the growth of certain kinds of cells. Studies also find that women taking a placebo experience reduced symptoms, too, but generally not as much as with supplements.