By Angela Grassi, MS, RDN, LDN 

 Medically reviewed by Sanaz Ghazal, MD

Resveratrol, an antioxidant found in the skin of grapes, berries, red wine, and peanuts has shown encouraging results for helping restore hormone balance and fertility in women with polycystic ovary syndrome (PCOS), according to a study published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism.

Women with PCOS tend to have higher levels of male hormones, such as testosterone, as well as high levels of insulin, which can lead to infertility and type 2 diabetes. Traditional treatments for PCOS have included diet and lifestyle modifications, insulin-sensitizing medications, birth control, and ovulation inductors.

Research into the role of certain dietary supplements, like resveratrol, has started to get more attention as women with PCOS want safer and more natural treatments to improve their condition.1

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Breaking Down the Study

In the study, 30 patients with PCOS were randomly given either a resveratrol supplement (1,500 mg) or a placebo pill daily for three months. The women had blood samples taken of the androgen levels of testosterone and dehydroepiandrosterone sulfate (DHEAS), a precursor to testosterone, at the start and end of the study, as well as an oral glucose tolerance test to detect any diabetes risk factors.

The results of the study were very encouraging. Women who received the resveratrol supplement saw a 23 percent reduction in their total testosterone levels and 22 percent reduction in DHEA sulfate levels. The other good news was that women who were given resveratrol improved their insulin levels. In fact, fasting insulin levels dropped by a whopping 32 percent during the three-month study.1

What This Means for You

In general, resveratrol has been known for anti-aging, anti-cancer, and cardioprotective properties. Rich in polyphenols and antioxidants, resveratrol has been shown to have the potential to fight inflammation as well as reduce cholesterol and insulin in other populations.2 Resveratrol in red wine has been suggested to be the secret to the “French Paradox,” a reason why people living in France have low levels of heart disease despite a high saturated fat diet (comprised mainly of cheese and butter) and high rates of smoking.3

Resveratrol might be effective at improving fertility by improving egg (oocyte) quality and maturation, both of which can be limited in women with PCOS.

But before you uncork that bottle of cabernet, know this: the amount of resveratrol in the PCOS study was 1,500 mg daily, the equivalent of drinking between 100 to 200 liters of wine a day. This was the first study to explore the benefits of resveratrol in women with PCOS and more studies are needed to show its benefits and optimal dosing. Previous animal studies involving mice did find that resveratrol improved androgens, insulin, leptin and resulted in weight loss.

Resveratrol failed to reduce insulin, weight, cholesterol, or inflammatory markers in a 6-month trial published in Pharmacological Research involving individuals with type 2 diabetes. It is worth noting that this study used a much lower dose of resveratrol (400-500 mg daily compared with 1500 in the PCOS study).1

What to Know About Resveratrol

In studies, resveratrol is well tolerated. Risks to pregnant women or to babies in utero are unknown. Interactions with other supplements or medications also remain unclear. Resveratrol supplements sold in stores are costly and sold at much lower dosages than what was used in the PCOS study.2

Until more research involving resveratrol and PCOS is available, there are several other dietary supplements that have shown to benefit women with PCOS including fish oil, vitamin D, n-acetylcysteine, and a combination of myo and d-chiro inositol.4

Of course, no supplement is a substitute for a healthy PCOS diet which should include plenty of antioxidant-rich whole foods such as berries, grapes, and nuts, the exact same foods that naturally contain resveratrol.5

It is also important to note that this was a small study and therefore the significance of the data is limited. More studies are needed to further investigate the effects of reservatrol on PCOS.

Sources

Banaszewska B, Wrotyńska-Barczyńska J, Spaczynski RZ, Pawelczyk L, Duleba AJ. Effects of Resveratrol on Polycystic Ovary Syndrome: A Double-blind, Randomized, Placebo-controlled Trial. The Journal of Clinical Endocrinology & Metabolism. 101(11):4322-4328. doi:10.1210/jc.2016-1858

Pezzuto JM. Resveratrol: Twenty Years of Growth, Development and Controversy. Biomol Ther (Seoul). 27(1):1–14. doi:10.4062/biomolther.2018.176

Ramírez-Garza SL, Laveriano-Santos EP, Marhuenda-Muñoz M. Health Effects of Resveratrol: Results from Human Intervention Trials. Nutrients. 10(12):1892. Published 2018 Dec 3. doi:10.3390/nu10121892

Günalan E, Yaba A, Yılmaz B. The effect of nutrient supplementation in the management of polycystic ovary syndrome-associated metabolic dysfunctions: A critical review. J Turk Ger Gynecol Assoc. 19(4):220–232. doi:10.4274/jtgga.2018.0077

Tomé-Carneiro J, Larrosa M, González-Sarrías A, Tomás-Barberán FA, García-Conesa MT, Espín JC. Resveratrol and clinical trials: the crossroad from in vitro studies to human evidence. Curr Pharm Des. 19(34):6064–6093. doi:10.2174/13816128113199990407

By Angela Grassi, MS, RDN, LDN
 Angela Grassi, MS, RDN, LDN, is the founder of the PCOS Nutrition Center.