But there is no reason to believe soy's effects will wear off. That's enough for the U.S. Food and Drug Administration to now allow manufacturers to put heart-health claims on soy products. Well, hold on. The whole soybean is superior to isoflavone supplements for reducing cholesterol, Seibel said. The FDA based its decision on soy protein, not isoflavones.
Research is mixed on whether soy can stave off bone loss and osteoporosis.
Seibel said eating whole soy foods is a woman's best strategy for the menopausal years, starting in her 40s. Supplements are acceptable for relief from hot flashes. He also recommended regular exercise and said that the herb black cohosh is an option if soy and exercise alone don't reduce symptoms. Seibel recently wrote an analysis of soy research that included 120 references. Medical people feel threatened by that statement.