Polycystic ovary syndrome (PCOS) issues include 2 out of the following 3:
1) oligo-ovulation/anovulation (usually experienced as menstrual bleeding irregularities
2) Hyperandrogenism (includes acne, excess body hair, hair thinning on scalp, elevated serum androgens
3) polycystic ovaries on a pelvic ultrasound.
The etiology and pathogenesis of PCOS are complicated but we do know the dominant mechanisms involved, including insulin resistance and hyperandrogenism. Obesity may contribute to PCOS due to the insulin resistance of excess body fat, but obesity can also be a consequence of PCOS. Strategies to increase weight loss and improve insulin sensitivity are core issues in overweight/obese women with PCOS. Tea and tea extracts have shown beneficial effects in patients with PCOS, but prior study results are inconsistent. The following summarizes a systematic review and meta-analysis to assess the effectiveness and safety of tea supplements for patients with PCOS.
Numerous electronic databases were searched from September 8, 2021. Of the 172 articles identified, six randomized controlled trials (n = 235) were included in the meta-analysis; all were published in English. Studies included women with a diagnosis of PCOS ages 18-42 and obese or overweight.
Three studies were conducted in Iran and one each in China, Britain, and Jordan. Double-blind methods were used in three trials. Interventions ranged from one to three months and including two cups of tea in two studies, capsules in two studies and tablets in dose of 500 mg /day in two studies. Green tea was used in four studies, one study used marjoram tea and one used spearmint tea. Tea supplements were compared with placebo in five studies and one compared tea with placebo and with metformin.
Five trials investigated the effect of tea supplements on weight; three reported on body mass index and waist-to-hip ratio; three reported on reproductive hormone testing; and three tested the effect of tea on fasting insulin levels. One study reported on the effects of the supplement on dermatology related quality-of-life and hirsutism scores.
Tea supplements compared with placebo significantly improved body weight, fasting blood glucose, and fasting insulin levels. Green tea and herbal tea demonstrated improvement in weight, fasting insulin, fasting glucose, and free testosterone in some patients. To improve fasting glucose, it appears that tea supplements need to be used at least for three months. Tea improved waist-hip rations in Asian but not Caucasian women with PCOS. In white patients but not Asian, tea supplementation improved body weight and fasting insulin. Compared with placebo, tea supplements did not cause significant adverse effects.
Commentary: This review has some problems including short duration of studies, small number of studies, small sample size and mixed patient populations. In addition, dosages and delivery forms of the teas varied among the studies. Most of the patients were obese, whereas 20% to 60% of women who have PCOS are not obese. Despite these issues in the studies, green tea, spearmint tea and marjoram tea should have a place in PCOS management. Readers might want to know that in 2018, a study of chamomile was published documenting lowering of testosterone levels in women with PCOS (Heidary M, Yazdanpanahi Z, Dabbaghmanesh M, et al. Effect of chamomile capsule on lipid- and hormonal-related parameters among women of reproductive age with polycystic ovary syndrome. J Rres Med Sci 2018;23).
Reference: Shen W, Pan Y, Jin B, et al. Effects of tea consumption on anthropometric parameters, metabolic indexes and hormone levels of women with polycystic ovarian syndrome: A systematic review and meta-analysis of randomized controlled trials. Front Endocrinol (Lausanne). December 13, 2021;12:736867
