The study you refer to found that resveratrol, an antioxidant found in red wine and in the skin of grapes, prevented the negative health effects of weight gain in mice - enlarged livers, high insulin levels and diabetes - and reduced the risk of death by 31 percent. Researchers from Harvard Medical School and the National Institute on Aging gave resveratrol to mice to see how it would affect those fed a high-fat diet (60 percent of calories came from fat) compared to mice who got the high-fat diet but no resveratrol and mice fed a healthy (for a mouse) diet. In addition to living longer and avoiding the perils of a high- fat diet, the mice who received resveratrol also performed better on tests of balance and coordination as they got older than did the other high-fat diet animals in the study.
Exactly how resveratrol worked to benefit the mice isn't known, but earlier research suggested that it can mimic the effects of caloric restriction in extending longevity. We've long known that mice fed a nutritious diet that contains 40 percent fewer calories than a standard mouse diet will live up to 50 percent longer than those that get the usual complement of calories. The gene that controls this process is called SIRT-1. Researchers trying to figure out how to activate SIRT-1 have been looking at resveratrol as the answer. This new study didn't show specifically that resveratrol activated SIRT-1, but findings to be published soon are expected to address this issue.
To get the resveratrol dose given to the mice in this study (24 mg of resveratrol per kilogram of body weight), you would have to drink far more wine than is sensible, or even possible, for a human being to drink. If you do drink, switching to red wine might be a healthier option than other forms of alcohol, but if you don't drink, resveratrol is not a reason to start. The lead author of the study, David Sinclair, told the New York Times that he has been taking resveratrol at a daily dose of five mg per kilogram (mice fed that amount in a follow-up trial did better than mice on a standard diet but not as well as the mice that got 24 mg per kilogram). Dr. Sinclair also said he is having a physician check his metabolism regularly because of concerns that impurities in the supplements could prove harmful. So far, he's had no problems.
Ongoing safety testing should tell us how much resveratrol is safe for human consumption. Resveratrol supplements are available, but since they're unregulated by the FDA, we don't know if they really contain the dose listed on the label. I doubt that you could get a dose equivalent to that fed the mice from currently available supplements, but you can obtain resveratrol simply by eating more fruits with deep red and purple color, such as grapes, blueberries, raspberries, blackberries and cranberries. Some supplements made from grape seeds and red wine claim to provide resveratrol, but don't tell you how much. I think we'll have to wait for more research and better products.
Andrew Weil, M.D.