Effect of intestinal production of equol on menopausal symptoms in women treated with soy isoflavones.

OBJECTIVE

To evaluate the effect of soy isoflavones on menopausal symptoms in women who do and who do not produce equol, a daidzein metabolite.

METHOD: A randomized, double-blind, placebo-controlled clinical trial was conducted over 6 months with 96 healthy menopausal women. After taking take 135 mg of isoflavones daily for 1 week, the women in the study group were assigned to the equol-producing (EP) or the non-EP group according to the presence or absence of equol in their urine. Menopausal symptoms were evaluated using a modified Kupperman Index.

RESULT: Compared with the placebo group, the scores for hot flashes and excessive sweating were significantly reduced after 3 months, and the scores for weakness, palpitations, limb paresthesia, and total symptoms after 6 months, in the EP group only.

CONCLUSIONS

Isoflavone supplementation improves menopausal symptoms only in women with the ability to produce equol.