The claims in magazine ads, on TV and all over the Internet are eye-catching. For instance: "Harvard researcher says resveratrol is the Holy Grail of aging research." Research from other prestigious institutions such as Johns Hopkins, the Salk Institute and the University of California is also often cited to make the case that resveratrol holds the secret to longevity. It’s true that many eminent scientists are interested in resveratrol, and some findings have been tantalizing.
Resveratrol is one of many naturally occurring plant chemicals called polyphenols. It is found in grapes, peanuts, mulberries and blueberries, as well as spruce, eucalyptus and other plants (not all of them edible). Red wine is rich in it, and white wine has some, too. Many reports have called resveratrol the ingredient in wine that appears to protect wine drinkers from cardiovascular disease—the so-called "French paradox. "The "paradox" is that the French eat a lot of cheese and other fatty foods, but are healthier, presumably because of the red wine they drink.
First isolated in 1940, the resveratrol molecule has been a subject of scientific study ever since. And, indeed, in laboratory studies it is the equivalent of a three-ring circus. Under a microscope, it appears to do nearly everything.
What some studies suggest
- In studies of yeasts, certain worms and other small organisms, high doses of resveratrol have lengthened lifespan. Mice, too, live longer when given high doses of resveratrol. These findings brought forth loud exclamations of "eureka!" from some researchers, and gave rise to the anti-aging claims of supplement marketers.
- It is, or sometimes behaves like, a plant estrogen. As such, it may activate genes controlled by estrogen. This raises the possibility that it might promote certain cancers. On the other hand, it sometimes is, or behaves like, an anti-estrogen, and this raises the possibility that it might help suppress those same cancers.
- It is an antioxidant. Some researchers have proposed that it thus may help protect against cardiovascular disease, but this is far from proven. It’s true that wine, especially red wine, has heart benefits, but it’s not known to what extent resveratrol is involved in this. On the other hand, good studies have found that resveratrol, under some circumstances, can act like a pro-oxidant and can thus damage cells. It has been theorized that this property might be useful for treating cancer.
- It can have anti-inflammatory and anti-prostaglandin effects. (Prostaglandins are chemicals involved in many bodily processes, including pain.) That is, resveratrol has something in common with aspirin and other nonsteroidal anti-inflammatory drugs, which quell inflammation and pain.
- Lab studies suggest that resveratrol has neuroprotective properties. If these could somehow be harnessed, they might help prevent some of the degenerative diseases of aging.
The future of resveratrol
Will our grandchildren take a resveratrol capsule every morning and live to be 100 without having to see a doctor? Should you get a supply of resveratrol pills and start taking them now? We don’t know about the grandchildren, but the answer to the second question is no. There have been no good human studies of resveratrol. It appears, so far, to be safe, but its long-term effects are an open question. Any substance that seems to do almost everything and can play opposite chemical roles deserves careful study.
Is it our friend or foe? Or both? Or neither? If it’s beneficial, what dose would you need? No one knows yet. Supplement marketers warn that delay could be dangerous, and they also say the big drug companies will one day be selling you resveratrol at 10 times the price. If that comes to pass, at least the drug companies will have had to show some evidence of safety and effectiveness via human studies. This is not the case with dietary supplements, which can make many vague health claims with no proof.
Taking resveratrol seriously
Science is not ignoring resveratrol. It is being tested at many research institutions here and abroad as a treatment for such disorders as diabetes, metabolic syndrome, and Alzheimer’s disease, as well as for preventing cancer. One hope, apart from its possible preventive or life-extending uses, is that resveratrol will prove useful for treating heart disease and cancer.
Many modern medicines come from plants; aspirin is perhaps the best-known example. Still, not all remedies extracted from plants have proven successful. In addition, many nutrients and phytochemicals work best as team players—not as isolated elements to be swallowed in large doses.
In a small English study of healthy young people, published in the American Journal of Clinical Nutrition in 2010, resveratrol increased cerebral blood flow in study subjects when they were performing mental tasks. However, this did not result in improved cognitive function. And a small 2011 study of obese people published in Cell Metabolism showed that 30 days of resveratrol supplementation resulted in potentially beneficial metabolic changes similar to those occurring during calorie-restricted diets. Several small recent studies found that resveratrol supplements can help people with type 2 diabetes control blood sugar and/or improve insulin sensitivity.