There are a number of animal and in vitro studies showing that resveratrol may have value for individuals with insulin insensitivity or heart disease and may even help extend lifespan. One study, appearing in Current Biology (2006; 16(3):296–300), found that resveratrol increased lifespan in fish in a dose-dependent manner. In addition, resveratrol delayed age-related deterioration of motor ability and cognitive skills.
Another study, published in Nature (2006; 444(7117):337–342), reported that resveratrol improved health and survival in mice fed a high-calorie diet. In this study, one group of mice was fed a normal diet, a second group was fed a high-calorie diet containing 60% fat, and a third group was fed the same high-calorie diet supplemented with resveratrol (22.4 mg/kg/day). Mice consuming the high-fat, high-calorie diet developed elevated insulin levels and other markers associated with diabetes. Mice receiving resveratrol along with the high-fat diet demonstrated improved insulin sensitivity comparable to mice fed the normal diet.
Some human studies have also been conducted. A double-blind, placebo-controlled crossover study published in Nutrition, Metabolism and Cardiovascular Diseases (e-published ahead of print July 31, 2010) examined 19 overweight subjects. Participants received either 30 mg, 90 mg, or 270 mg of resveratrol daily for one week, or a placebo. One hour after supplementation, resveratrol produced a dose-dependent improvement in flow-mediated dilation of the brachial artery. This finding may help explain the cardiovascular benefits often attributed to red wine.
Additional research published in the British Journal of Nutrition (e-published ahead of print March 9, 2011) found that resveratrol reduced oxidative stress and improved insulin sensitivity in patients with type 2 diabetes.
In an animal study published in Carcinogenesis (September 2007; 28(9):1946–1953), resveratrol was found to offer protection against prostate cancer. Resveratrol is a phytoalexin, a compound produced by plants to protect against invading microorganisms, and it also functions as a potent antioxidant. Beginning at five weeks of age, mice bred to be prone to prostate cancer were divided into two groups. One group received a standard diet, while the other received the same diet supplemented with resveratrol. The animals were evaluated at 12 and 28 weeks of age. In the resveratrol-supplemented group, the incidence of prostate cancer was reduced by 7.7-fold.
