Effects of polyphenol in women with polycystic ovary syndrome: A systematic review and meta-analysis of randomized controlled trials

Objective Polycystic ovary syndrome (PCOS) is an endocrinopathy with a high prevalence in women of reproductive age. Different treatments were tested to increase insulin sensitivity and hormone regulation, and recently polyphenols have emerged as a promising option for these women. We aimed to perform a systematic review and meta-analysis of randomized clinical trials (RCTs) comparing polyphenols to placebo in PCOS. Design A systematic review and meta-analysis. Methods PubMed, Cochrane Library, and Embase databases were searched for RCTs comparing polyphenols to placebo. Random-effects model was used to calculate the Mean Difference (MD) and Standardized Mean Difference (SMD), with 95% confidence interval (CIs). Results A total of fifteen RCTs comprising 916 patients were included, of whom 445 (49 %) received polyphenols. Compared to placebo, polyphenols significantly reduced serum insulin level (MD −2.49; 95 % CI [−3.72, −1.25]; p < 0.01), BMI levels (MD −0.12; 95 % CI [−0.18, −0.06]; p < 0.01), and LH levels (MD −0.87; 95 % CI [−1.54, −0.20]; p = 0.01). There was no significant difference between groups in testosterone levels (SMD −0.14; 95 % CI [−0.53, 0.25]; p = 0.48). Conclusion In this meta-analysis polyphenols were associated with a reduction in serum insulin, LH levels, and BMI in women with PCOS, compared to placebo. These findings support the effectiveness of polyphenols in women with PCOS. Significant statement There are no comprehensive systematic recommendations for polyphenols in PCOS treatment. However, increasing evidence has highlighted its substantial impact on women's health. This systematic review and meta-analysis provide evidence for the efficacy of polyphenols in reducing serum insulin, LH, and BMI in women with PCOS compared with placebo.