Effects of genistein on the endometrium: ultrasonographic evaluation

Abstract

The aim of our study was to evaluate the effects of isoflavones on climacteric-related symptoms and on the endometrium in postmenopausal women, in a prospective, open, randomized, clinical trial performed at the Menopause Clinic of our Department. Seventy postmenopausal women were randomly assigned to two treatment groups receiving 12 cycles of treatment with genistein (group A) or calcium (group B). In all patients ultrasonographic endometrial thickness and Kupperman Index (KI) were evaluated at baseline and after 6 and 12 cycles of treatment. At baseline no significant difference was detected in endometrial thickness and in KI between groups A and B. After 6 and 12 cycles of treatment, no significant difference was observed in endometrial thickness between or within groups. Endometrial thickness was lower than 5 mm in all cases before and during treatment except in two cases in group B and in one case in group A after 12 months. At 6 and 12 months, the KI was significantly (p < 0.05) lower in group A in comparison with baseline values and group B. We conclude that genistein administration reduces climacteric symptoms in postmenopausal women and does not increase endometrial thickness.

Effects of genistein on hot flushes in early postmenopausal women: a randomized, double-blind EPT- and placebo-controlled study.

“…Indeed, our study showed no difference in endometrial thickness between placebo, genistein, and EPT groups. This finding confirms and extends recent published data 30 showing that the administration of 36 mg/day of genistein for 12 months did not induce endometrial growth when compared with placebo; however, our data are, at least in our opinion, more impressive because we have administered a higher dose (54 mg/day of genistein) and the isoflavone effect was controlled versus both placebo and EPT. …”

Isoflavones – Mechanism of Action and Impact on Breast Cancer Risk

“…Unfortunately, the results of many studies are inconsistent due to a lot of bias [18,19]. So far, there is low evidence for any well-defined estrogen-like or anti-estrogen-like effect in humans [20,21]. One possible reason for the apparently incoherent findings could be the quantitatively and qualitatively variable composition of phytoestrogens in food stuff and their complex metabolism with the synthesis of miscellaneous derivates which partially show diverse biologic activities.…”

Soy protein isolate with isoflavones does not prevent estradiol-induced endometrial hyperplasia in postmenopausal women: a pilot trial

“…In contrast, RCTs invariably show no proliferative effect of isoflavones on the postmenopausal endometrium, regardless of the isoflavone source and dose (summarized in Table 5). 16,[41][42][43][44][45][46]57,58 From the clinical and epidemiological studies, one can hypothesize that isoflavones have an inert effect on the endometrium, similar to raloxifene 10 or that isoflavones have an antiproliferative effect on the meno- Menopause, Vol. 10, No.…”