Polycystic ovary syndrome (PCOS) is a familiar condition to any women’s health practice. The dominant mechanisms that can be addressed in the management of PCOS are insulin resistance and hyperandrogenism. While genetic and environmental influences are involved in the etiology, the research on natural medicines to address the insulin resistance and hyperandrogenism is quite extensive.
The most prescribed medication for PCOS is metformin, although other medications such as birth control pills, hormone IUDs and anti-androgens are often part of controlling some of the manifestations of PCOS such as abnormal uterine bleeding, acne, and hirsutism.
Green tea is one of the botanicals that has emerged as having a potential beneficial effect in PCOS. In the current randomized clinical trial, the effects of green tea tablets were compared with metformin and placebo on ovulation, menstrual cycle regularity, and antioxidant biomarkers in patients with PCOS.
Women with PCOS were recruited in Iran in 2021. Inclusion criteria included: reproductive age, a diagnosis of PCOS, insulin resistance, a body mass index (BMI) of > 25 kg/m 2 multiple ovarian cysts with follicles measuring 2-6 mm in diameter, and irregular menstrual cycles.
Women were divided into three groups of 35 each. The first group took 500 mg of green tea leaf powder plus a standardized extract containing 50 mg of total polyphenols twice daily for one week and then 1,500 mg daily for three months. The second group took 500 mg of metformin daily for three months and the third control group took 500 mg placebo pills for three months.
Baseline and post treatment samples were drawn to measure oxidative stress markers and antioxidant capacity, BMI, blood pressure, hip and waist circumferences, and pelvic ultrasounds.
The final analysis included 33 in the green tea group, 29 in the metformin group, and 32 in the placebo group.
Results: Women in the green tea group experienced more significant reductions in BMI, waist circumference, hip circumference, and blood pressure compared with the other groups although the changes were not significant. The only significant difference among the groups was at the end of the study, menstrual cycle lengths were 32.22 ± 12.78 days in the green tea group, 48.72 ± 37.06 days in the metformin group, and 42.34 ± 28.48 days in the placebo group. There were no significant changes in any of the groups in biochemical, hormonal, or antioxidant indices but there were nonsignificant changes including lower leptin levels in the green tea group and lower blood glucose levels in the metformin group. Compared with baseline, there were significant increases in insulin and follicle-stimulating hormone levels in the green tea group.
Commentary: Three months is a short duration period for a condition such as PCOS. In my view, 6 months would be more informative.
An earlier but recent systematic review and meta-analysis of green tea use and the effect on weight loss in women with PCOS was published in 2022. The outcomes listed in the study protocol were body weight, fasting insulin, body mass index, body fat percentage, daily caloric intake, waist circumference, hip circumference, and waist/hip ratio. Four double-blind RCTs were included, with a total of 169 women: 85 in the green tea group and 84 in the placebo group. A significantly lower body weight (kg) for the green tea group was observed with a mean difference, -2.80. (ref: Colonetti L, Grande A, Toreti I, et al. Green tea promotes weight loss in women with polycystic ovary syndrome: Systematic review and meta-analysis. Nutr Res 2022 Aug:104:1-9.) In another systematic review, published in 2021, of 314 articles found in the search, four human studies and four animal studies were included. All studies in women with PCOS showed the effects of green tea extract on weight loss. Green tea extract’s effect on decreasing testosterone levels in women and luteinizing hormone levels in animals were also reported. In addition, increases in follicle stimulating hormone and progesterone levels in animal models were observed. Green tea extract also improved fasting blood sugar and insulin levels. The effect of green tea extract on inflammatory parameters, such as TNF-alpha and IL-6 and antioxidant status, was limited to animal studies. (ref: Maleki V, Taheri E, Varshosaz P, et al. A comprehensive insight into effects of green tea extract in polycystic ovary syndrome: a systematic review. Reproductive Biology and Endocrinology 2021; 19;147)
Green tea should be added to the list of other botanical and nutraceutical ingredients found to address insulin resistance and hyperandrogenism and the consequences in women with PCOS.
Reference: Yavangi M, Rabiee S, Sanavi Farimani M, et al. The effects of green tea tablets and metformin on ovulation and menstrual cycle regularity in women with polycystic ovary syndrome. J Med Life. January 2024;17(1):109-115.
