Soy isoflavones in the management of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) increases risk of type 2 diabetes mellitus (T2DM), coronary heart disease and endometrial cancer

Polycystic ovary syndrome (PCOS) is an endocrine condition associated with elevated insulin levels, impaired glucose metabolism, hormone imbalance and dyslipidaemia.

Common in women of reproductive age, PCOS causes a number of symptoms, including irregular menstrual cycles, excessive hair growth, acne and weight problems. In addition, PCOS increases risk of type 2 diabetes mellitus (T2DM), coronary heart disease, and endometrial cancer.

The symptoms and health risks associated with PCOS make treatment of the condition a priority. One area of research interest is soy isoflavones, which have been shown to offer protection against a variety of related health concerns, including menopausal symptoms and coronary heart disease.

However, data are limited on the effects of soy isoflavones on health measures in women with PCOS (hormonal status, lipid concentrations, inflammation and oxidative stress markers).

A 2016 study published in the Journal of Clinical Endocrinology & Metabolism sought to clarify the metabolic effects of soy isoflavones in women with PCOS. The randomised, double-blind, placebo-controlled trial included 70 PCOS sufferers between the ages of 18 and 40.

The women were assigned to take either 50mg per day of soy isoflavones (containing 37.5mg of genistein, 10mg of daidzein and 2.5 mg of glycitein) or placebo for 12 weeks. Of note, this level of soy isoflavones (50mg) is equivalent to 500mL (16oz) of soy milk. At the beginning and end of the study, the researchers measured metabolic, endocrine, inflammation and oxidative stress biomarkers.

After 12 weeks, treatment with isoflavones significantly decreased circulating serum levels of insulin (1.2+4.0 vs 2.8+4.7 IU/mL; p< .001). In addition, statistically significant improvement was seen in measures of insulin resistance. The treatment group also experienced significant reductions in androgen and triglyceride levels, as well as increases in glutathione.

More research is needed to confirm these findings, but this study suggests that soy isoflavones may be useful in mitigating some of the concerning effects of PCOS.