USUAL CONSUMPTION OF PLANT FOODS CONTAINING PHYTOESTROGENS AND SEX-HORMONE LEVELS IN POSTMENOPAUSAL WOMEN IN WISCONSIN

Consumption of phytoestrogens may reduce hormone-dependent cancer risk through alterations in the actions or metabolism of steroid hormones. Studies in humans of phytoestrogen-hormone interactions have been lim ited and inconsistent. Relations between the consumption of phytoestro gen-containing foods and serum sex hormones and sex hormone-binding gl obulin were studied in a population-based sample of postmenopausal wom en who participated in the Nutritional Factors in Eye Disease Study of the Beaver Dam Eye Study. Information on phytoestrogen-containing foo ds (broccoli, carrots, cauliflower, chili, dark bread, peas, and dried beans) was co Ilected by inteviewer-administered food-frequency quest ionnaires. Estrone, sex hormone-binding globulin, dehydroepiandrostero ne sulfate, and total and free testosterone were measured. Analyses in cluded 246 postmenopausal women not taking hormone replacements. Parti al correlations between hormones and intake of phytoestrogen-containin g foods were computed with adjustment for age, body mass index, years since menopause, and total energy intake. Number of standard servings per week of whole-grain products from the dark bread group was inverse ly associated with total testosterone (r = -0.20, p = 0. 002). Althoug h not statistically significant, other hormones displayed similar inve rse associations with dark bread consistent with a common metabolic pa thway. Although the magnitude of association was small, the data are c onsistent with the possibility that consumption of some phytoestrogen containing foods may affect levels of testosterone in postmenopausal w omen.