Effects of Phytoestrogens in Alleviating the Menopausal Symptoms: A Systematic Review and Meta-Analysis

The aim of this research was to perform a systematic review of the efficacy of non-hormonal herbal drugs in the treatment of vaginal atrophy in postmenopausal women. Three electronic databases were systematically searched from their inception to May2015: PubMed, Cochrane Library (Cochrane Central Register of Controlled Trials) and Scopus. In this meta-analysis, vaginal maturation value was considered as the primary outcome measurement. Sample size, mean values before and after treatment and standard deviations for each outcome measurement were used for meta-analysis. Pooled difference in means calculated as the main effect size. A random-effects model was used to pool the data across studies. Heterogeneity was evaluated using Cochrane Q value. For quantification of the heterogeneity, the I2 index was used. The meta-analysis of 10 phytoestrogen studies showed that while the standardized mean difference of vaginal maturation value increased 0.164% (95% CI: -0.746 to -.0.419), this increase was not statistically significant (P = 0.582). The meta-analysis of seven soy studies showed that while the standardized mean difference of vaginal maturation value increased 0.072% in (95% CI: -0.42 to 0.5.), this increase was not statistically significant (p = 0.777). . Overall it can be concluded that soy phytoestrogens and isoflavones can improve vaginal atrophy in postmenopausal women, although this effect was not statistically significant.