Polycystic ovarian syndrome (PCOS) is a common endocrine problem that is diagnosed in reproductive aged women. It’s complex and involves multiple body systems but is associated with hyperinsulinemia, impaired glucose metabolism, hyperandrogenism and dyslipidemia. It is estimated that 5-6 million women in the United States have PCOS. The manifestations of PCOS can include irregular/infrequent menses or no menses at all, infertility, polycystic ovaries, abnormal hair growth (hirsutism), hair thinning, acne, weight gain and in time, an increased risk for type 2 diabetes, cardiovascular disease and endometrial cancer.
PCOS is a strong area for natural medicine that includes good science on nutrition, exercise, N-acetyl cysteine, myo-inositol, d-chiro-inositol, cinnamon, spearmint, licorice, fish oils and more.
The current study compared women who received a soy isoflavone supplement for 12 weeks with placebo. The study enrolled 70 women between the ages of 18 to 40, and who met the diagnostic criteria, called the Rotterdam criteria, for a diagnosis of PCOS. Women were given either a 50 mg soy isoflavone capsule per day or a placebo daily, for 12 weeks. All women also took metformin at 500mg/day which was increased to 1,500 mg/day. One of the uses of metformin is to improve insulin sensitivity which in women with PCOS, hopefully leads to lowered androgens and regular ovulation with regular menses. No other dietary supplements were allowed.
The women who took the soy isoflavone supplement had significantly improved insulin resistance (measured by a decrease in serum insulin levels and two other important tests that measure insulin resistance and insulin sensitivity called the HOMA-IR and the QUICK1), as well as improvement in androgen levels and triglycerides.
Commentary: Soy foods in the diet of women with PCOS have been a staple of my nutritional advice for women with PCOS, due to other evidence that soy phytoestrogens can improve lipids and lower some of the free testosterone. I would not be inclined to just rely on a soy isoflavone supplement or soy foods to fully address PCOS, but in terms of medicinal foods, soy foods and/or a soy isoflavone supplement is an important dietary influence for women with PCOS. Do not be misled by the term “phytoestrogen”, some of the natural compounds in soy. Soy does not contain estrogen nor does it increase estrogen levels, nor does it cause hormonal cancers.
Jamilian M, Asemi A. The effects of soy isoflavones on metabolic status of patients with polycystic ovarian syndrome. J Clinical Endocrinology and Metabolism. 2016, August, first published online