We would all like to live longer. The most promising longevity research indicates that severe calorie restriction might extend life span, but such a diet is difficult to follow. Resveratrol, a phytochemical found in red wine, has been evaluated as a possible way out of the dilemma. When given to obese mice on a high calorie diet, it produced a number of changes associated with improved health, such as increased insulin sensitivity, and it increased survival. Perhaps by taking resveratrol you could eat as much as you want and get fat without suffering the usual consequences. Perhaps you could get the longevity benefits of severe calorie restriction without restricting calories.
In addition to fat mice, resveratrol also extends the life of Saccharomyces cerevisiae, Caenorhabditis elegans and Drosophila melanogaster (yeast, nematodes, and fruit flies). But a study in non-obese mice found no increase in survival (although it did find several signs of improved health). Besides the anti-aging claims, there is also some evidence from in vitro and animal studies that it might have cardiovascular effects and anti-cancer effects.
The ads for one product (Vinotrol) say:
• “Life is short… or maybe not.
• Top Harvard researcher says it’s “the Holy Grail of aging research.”
• As seen on CBS “60 Minutes.”
• Harvard Medical School, Johns Hopkins, Salk Institute and UC Davis Medical Research Proves that Powerful Red Wine Extract Holds the Secret to Living a Longer, Healthier and More Vibrant Life
• Has the “French Paradox” finally been explained?
• Trick your body into “aging in slow motion.”
• Can you live years longer and feel years younger?
• “extends the life of every species it’s been given to.”
• Vinotrol, with 50 mg of resveratrol derived from grapes and roots, provides the equivalent of the resveratrol in 278 five ounce glasses of Pinot Noir.
• Promoting circulation, blood flow, [what’s the difference between these two?] immune system [ Mark Crislip has recently explained to us what that means], energy and healthy arteries.
• In tiny print at the bottom, it offers this disclaimer:
These statements have not been evaluated by the FDA. This product is not meant to diagnose or treat any disease. Vinotrol is not endorsed, associated or affiliated in any way with Harvard University, Johns Hopkins, Salk Institute or UC Davis Medical.
Dr. Stephen Barrett of Quackwatch has summarized the evidence for resveratrol at “Resveratrol: Don’t Buy the Hype.” It was recently evaluated by the “gold standard” publication The Medical Letter (Vol. 51 Issue 1321, p. 74-5, September 21, 2009). They pointed out “studies in humans are limited” and concluded
Resveratrol appears to produce some of the same effects as calorie-restricted diets that have reduced the incidence of age-related diseases in animals. Whether it has any benefit in humans remains to be established.
There is insufficient reliable information available about the effectiveness of resveratrol.
Its safety has not been established, and there is speculation that it might potentiate certain cancers. The Natural Medicines Comprehensive Database concluded
There is insufficient reliable information available about the safety of resveratrol when used in supplemental doses in amounts greater than those found in foods.
There are concerns about interactions with other drugs. It has antiplatelet effects and preliminary evidence shows that resveratrol might inhibit the cytochrome P450 enzymes, CYP3A, CYP1A, and CYP2E1.
Resveratrol products have been associated with scams and false advertising. Researcher Dr. David Sinclair is quoted in ads without his permission. He commented
His lab showed that mice fed the chemicals live at least 15% longer than normal mice. But to get such benefits, human beings might have to consume up to 5 grams of resveratrol a day, he says. That’s about 80 pills, at doses found in a typical bottle.
The properties of resveratrol are intriguing, and it may turn out to be a useful drug. But so far the studies on resveratrol are pre-clinical studies. We have no data on its effects in humans. Few people would want to take a proposed prescription drug that had not yet undergone clinical trials: why should resveratrol be any different? In the absence of clinical trials, resveratrol might be recommended for obese mice, but not for men.
*This blog post was originally published at Science-Based Medicine*