The disease-fighting compound found in red wine and grapes has been shown to lower blood sugar and protect against diabetes in animal studies. Now, researchers have found it can do the same in humans.

Scientists have long known that resveratrol is one of the key factors behind the “French paradox”—the phenomenon in which our Gallic cousins can eat fatty foods and guzzle wine but still have lower incidences of heart disease and obesity than Americans. 

Animal and laboratory studies have found that resveratrol, a potent disease-fighting compound in grapes, peanuts and some berries, may also lower the risk of cancer and even boost lifespan. A January 2011 research review published in the Annals of the New York Academy of Sciences concluded that resveratrol decreases blood sugar in rats and helps protect against diabetes. But until recently, scientists didn’t know if these results transferred to humans. Now, a group of Indian researchers have found that they do.

Their study, published Aug. 8, 2012 in Nutrition Research, involved 62 people with type 2 diabetes. The study participants were divided into two groups: One group received blood-sugar-lowering drugs, while the other group received the drugs plus 250 mg of resveratrol supplements daily for three months. 

At the end of the study, the resveratrol group had significant improvements in hemoglobin A1C, a marker of excess blood sugar, and systolic blood pressure (128 versus 140 for the non-resveratrol group). Systolic blood pressure is the top number in a blood-pressure reading. In addition, the resveratrol group had notably lower cholesterol levels.

All of these factors contribute to diabetes, leading the researchers to conclude that resveratrol could be helpful in treating the disease.