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 .
The Effect of Dietary Soy Supplementation on Hot Flushes
Objective To assess the effect of daily dietary supplementation of soy protein isolate powder on hot flushes in post-menopausal women . Methods We carried out a double-blind , parallel , multi-center , r and omized  placebo-controlled trial of 104 post-menopausal women . Fifty-one patients ( age range 48–61 years ) took 60 g of isolated soy protein daily and 53 patients ( age range 45–62 years ) took 60 g of placebo ( casein ) daily . The study lasted 12 weeks . Using analysis of covariance , we analyzed changes from baseline in mean number of moderate to severe hot flushes ( including night sweats ) during treatment . Results Soy was significantly superior to placebo ( P < .01 in reducing the mean number of hot flushes per 24 hours after 4 , 8 , and 12 weeks of treatment . In particular , women taking soy had a 26 % reduction in the mean number of hot flushes by week 3 and a 33 % reduction by week 4 ( P < .001 by the Wilcoxon exact test ) . By the end of the 12th week , patients taking soy had a 45 % reduction in their daily hot flushes versus a 30 % reduction obtained with the placebo ( P < .01 ) . The overall rates of adverse effects were similar for soy and casein-placebo .  Twenty-five patients dropped out of the study : 11 in the soy group and 14 in the  placebo group . Gastrointestinal side effects were the most common cause of premature withdrawal from the study ( seven patients in each group ) . Conclusion Soy protein isolate added daily to the diet substantially reduced the frequency of hot flushes in climacteric women
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 .