Four trials that were not combined in meta-analyses suggested that extracts with high ( > 30 mg/d ) levels of genistein consistently reduced the frequency of hot flushes .
BACKGROUND Vasomotor symptoms , such as hot flushes and night sweats , are very common during the menopausal transition .
Hormone therapy has traditionally been used as a highly effective treatment , but concerns about increased risk of some chronic diseases have markedly increased the interest of women in alternative treatments .
Some of the most popular of these treatments are foods or supplements enriched with phytoestrogens-plant-derived chemicals that have estrogenic action .
OBJECTIVES To assess the efficacy , safety and acceptability of food products , extracts and dietary supplements containing high levels of phytoestrogens when compared with no treatment , placebo or hormone therapy for the amelioration of vasomotor menopausal symptoms ( such as hot flushes and night sweats ) in perimenopausal and postmenopausal women .
Modest hormonal effects of soy isoflavones in postmenopausal women.
Soy isoflavones have been hypothesized to exert hormonal effects in postmenopausal women . To test this hypothesis , we studied the effects of three soy powders containing different levels of isoflavones in 18 postmenopausal women .  Isoflavones were consumed relative to bodyweight [ control : 0.11 + /- 0.01 ; low isoflavone ( low-iso ) : 1.00 + /- 0.01 ; high isoflavone ( high-iso ) : 2.00 + /- 0.02 mg/kg/day ] for 93 days each in a r and omized crossover design . Blood was collected on day 1 of the study ( baseline ) and days 36 - 38 , 64 - 66 , and 92 - 94 of each diet period , for analysis of estrogens , and rogens , gonadotropins , sex hormone binding globulin ( SHBG ) , prolactin , insulin , cortisol , and thyroid hormones . Vaginal cytology specimens were obtained at baseline and at the end of each diet period , and endometrial biopsies were performed at baseline and at the end of the high-iso diet period , to provide additional measures of estrogen action . Overall , compared with the control diet , the effects of the low-iso and high-iso diets were modest in degree . The high-iso diet result ed in a small but significant decrease in estrone-sulfate ( E1-S ) , a trend toward lower estradiol ( E2 ) and estrone ( E1 ) , and a small but significant increase in SHBG . For the other hormones , the few significant changes noted were also small and probably not of physiological importance . There were no significant effects of the low-iso or high-iso diets on vaginal cytology or endometrial biopsy results . These data suggest that effects of isoflavones on plasma hormones per se are not significant mechanisms by which soy consumption may exert estrogen-like effects in postmenopausal women . These data also show that neither isoflavones nor soy exert clinical ly important estrogenic effects on vaginal epithelium or endometrium
Four trials that were not combined in meta-analyses suggested that extracts with high ( > 30 mg/d ) levels of genistein consistently reduced the frequency of hot flushes .
BACKGROUND Vasomotor symptoms , such as hot flushes and night sweats , are very common during the menopausal transition .
Hormone therapy has traditionally been used as a highly effective treatment , but concerns about increased risk of some chronic diseases have markedly increased the interest of women in alternative treatments .
Some of the most popular of these treatments are foods or supplements enriched with phytoestrogens-plant-derived chemicals that have estrogenic action .
OBJECTIVES To assess the efficacy , safety and acceptability of food products , extracts and dietary supplements containing high levels of phytoestrogens when compared with no treatment , placebo or hormone therapy for the amelioration of vasomotor menopausal symptoms ( such as hot flushes and night sweats ) in perimenopausal and postmenopausal women .