Some of us who like to enjoy a glass of wine on a regular basis felt vindicated by recent news reports that a substance in red wine, called resveratrol, may protect the heart and even extend life.

Of course, our joy was quickly dampened when we heard we would have to drink at least 750 bottles of red wine daily to gain these benefits! It makes sense to wonder if we can we get these same benefits with resveratrol supplements.

Scientists believe that resveratrol is the component of red wine responsible for its heart-protective effects compared with other alcoholic beverages. Now a Harvard study has found that mice fed a high-fat diet plus 22 milligrams of resveratrol daily lived longer than mice fed a high-fat-diet only.

The resveratrol-fed mice gained as much weight as the high-fat-diet-only mice, but after one year 58 percent of the high-fat-only mice had died compared with 42 percent of the mice getting resveratrol or eating a healthy diet. And unlike the high-fat-only mice, those fed a healthy-diet or a high-fat diet plus resveratrol did not develop insulin resistance or accumulate fat in the liver and heart.

What could these findings mean for people? Well, if your diet consists of fast food three times a day, taking resveratrol supplements might keep your diabetes risk in check and help you live longer. But because we don't know whether resveratrol can prevent diabetes, you are better off sticking to the old-fashioned diet-and-exercise approach as the best proven way to avoid developing diabetes.

The possibility that resveratrol might increase longevity seems more interesting and exciting. Though efforts to find the fountain of youth have generally been unsuccessful, studies have shown that yeast, roundworms, fruit flies, and some fish lived longer when given resveratrol. Perhaps resveratrol will help us live longer, too.

Red wine and grapes are the most abundant sources of resveratrol, but drinking red wine isn't the answer. To get the same amount of resveratrol given to the mice, a 150-pound person would have to drink at least 750 bottles of red wine daily. 

Another choice is to purchase the resveratrol capsules that are available from many sources. Excited by the Harvard study and their hopes for an extended life, so many people have purchased dietary supplements of resveratrol that the suppliers are having problems keeping up with demand.

I heard one person say on a public radio station that spending $5 a day - that's $150 a month - on resveratrol was worth the gamble that it may keep him healthier and allow him to live longer. As with other unregulated dietary supplements, there is no way to know how much, if any, of the active substance is contained in these products.

It seems premature to start wolfing down resveratrol supplements, though. We don't know if resveratrol works in people as it does in mice, nor do we know whether it extends the life of mice that are not eating such high-fat diets. There is no information on what dose of resveratrol might prevent diabetes or extend life - or whether large doses might produce serious side effects.

David Sinclair, the Harvard researcher who led the mouse study does not appear to share these concerns. He has been taking resveratrol supplements for years and has co-founded a company to conduct human trials on resveratrol.