Vaginal atrophy is a common condition in postmenopausal women associated with vaginal and/or urinary symptoms such as vaginal dryness, itching, discomfort and dyspareunia (painful intercourse), dysuria (painful urination), urinary urgency and frequency. Estrogen is a dominant regulator of vaginal physiology. Estrogen-receptors are present in the vaginal tissues of both pre-menopausal and postmenopausal women. In a 12 week placebo-controlled study a vaginal isoflavone gel was shown to significantly improve symptoms of vaginal atrophy, benefits which were supported by changes in vaginal cytology. While these findings have no direct implications for soyfoods, they do show that the isoflavones in soybeans are biologically active.
Lima S et al. Effects of Glycine max (L.) Merr. soy isoflavone vaginal gel on epithelium morphology and estrogen receptor expression in postmenopausal women: A 12-week, randomized, double-blind, placebo-controlled trial. Maturitas 2014