Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age, affecting an estimated 5 million people in the United States alone. It causes women to produce higher amounts of hormones commonly associated with men—androgens, testosterone, and dehydroepiandrosterone sulfate (DHEAS). Symptoms include infrequent ovulation, weight gain, fatigue, unwanted hair growth, pelvic pain, and even infertility. As many as 60 percent of women with PCOS are also considered “pre-diabetic,” with insulin resistance and a much higher risk of developing type II diabetes. But new research recently published in the Endocrine Society’s Journal of Clinical Endocrinology and Metabolism has made the hopeful discovery that resveratrol, a humble antioxidant found in grapes, nuts, and berries, can significantly reduce the hormones that create hormone imbalances in women with PCOS, and improve insulin sensitivity.

Lead researcher Antoni Duleba, co-author of the study and a professor of reproductive medicine at the University of California, San Diego (UCSD) had previously found that statins, drugs that lower cholesterol, inhibit the mevalonate pathway—an important metabolic mechanism that plays a key role in multiple cellular processes, such as reducing the production of androgens. (Though dubbed "male" hormones because in males they trigger the development of typically male traits, androgens are also produced by ovarian tissues.) For this study, Duleba and his team in the Department of Reproductive Medicine sought other compounds that could do the same thing, eventually trying the compound resveratrol. “Resveratrol is biologically a different compound [from statins] but also interferes with the mevalonate pathway and has a similar effect on production of androgens by ovarian cells,” he tells mental_floss.

To test resveratrol’s potential, 30 women were randomly assigned to take either a resveratrol supplement or a placebo pill every day for three months. At the beginning and end of the study, they had their blood drawn to measure their hormone levels, as well as an oral glucose tolerance test to determine their diabetes risk factors.

Since resveratrol is not a drug, but a “nutritional additive,” it was difficult for the researchers to determine the right amount for women to take. “You can’t really translate doses into serum levels of resveratrol,” Duleba says, because “resveratrol is highly lipophilic”—it’s distributed in fat, and there are no good tools to measure the amount in fat cells. Therefore, he says, “We chose a medium concentration of one and a half grams per day and, fortunately, we got lucky.”

Their findings revealed statistically significant results. Total testosterone levels fell by 23.1 percent in the women who took the resveratrol. In contrast, the placebo group’s testosterone levels increased by 2.9 percent. For the resveratrol group, DHEAS also declined by 22.2 percent, while the placebo group saw a 10.5 percent increase in DHEAS levels.

Even more promising, the participants who took resveratrol also showed “reduced insulin levels and improved insulin sensitivity,” Duleba says, adding, “High insulin stimulates ovarian tissues and increases androgen production.” The link between diabetes and PCOS still needs to be explored—it’s not yet known if women with PCOS “are likely to have pre-diabetes because of androgens, or they are likely to have elevation of androgens because they are pre-diabetic.” Either way, resveratrol shows promise as a way to ameliorate several of the complications of the condition.

“It has been known for many years that in PCOS, the majority of women have insulin resistance and elevation of insulin,” Duleba says. Now, his research has revealed that resveratrol can reduce insulin levels, thus lowering the stimulation of the ovaries and directly reducing androgen production.

This is an exciting new line of research for the supplement resveratrol, which first made waves years ago as a magic bullet for extended life. The pharmaceutical giant GlaxoSmithKline bought patents on a “supposedly more absorbable form of resveratrol from Harvard professor David Sinclair,” recalls Duleba, but they never developed it despite spending “something like $700 million on it.”

While Duleba is enthusiastic about the results, he admits it is not a panacea, and there is much left to learn. They don’t yet know if it’s safe for use in pregnant women, for example, or if there’s a dose too high to be considered safe. He considers it a “very complex molecule,” and adds, “I don’t think it’s going to be the magic that will make us live forever, but I think it will find its place.”