Abstract
Because of the health concerns associated with hormone replacement therapy, many women are seeking alternative therapies. Compounds such as soy isoflavones appear to reduce the risk of some age-related diseases and to lessen the severity of menopausal symptoms. However, concerns regarding harmful effects of soy isoflavones on thyroid function have been reported. This 16-week, double-blinded, placebo-controlled trial evaluated the effects of soy isoflavones on thyroid-stimulating hormone in healthy postmenopausal women. The results of this study suggest that isoflavones obtained from either soymilk or supplements have no effect on thyroid-stimulating hormone in well-nourished postmenopausal women.