Dr. Thomas Walle, Medical University of South Carolina, presented the results at Experimental Biology 2004, as part of the scientific sessions of the American Society of Pharmacology and Experimental Therapeutics.
Resveratrol, a plant antioxidant found in abundance in grapes, wine, and peanuts, is widely sold as a dietary supplement with claims of numerous beneficial health effects. These range from extending life spans to preventing heart disease and cancer. However, these positive health effects have mainly been shown in cultured cells, and it has been unclear if resveratrol can reach the circulating blood in sufficient amounts to have therapeutic effects.
In the study by Dr. Walle and research associate Kristina Walle, C-14-Tagged resveratrol was administered both by mouth and intravenously to healthy volunteers. The researchers found that resveratrol (25-mg doses) is very well absorbed after oral dosing with most of the dose appearing in the urine in the first 12 hours. However, the urine contained resveratrol only as sulfate and glucuronic acid conjugates, none as the free, presumably active, form.
Likewise, the only blood samples containing free resveratrol were those drawn within 30 minutes after the intravenous injection. No free resveratrol was present in blood samples drawn after oral doses.
Based on this study's findings, Dr. Walle ways it would seem highly unlikely that resveratrol per se can have any effect on cardiovascular disease or cancer of such organs as the breast or prostate gland when consumed in the diet or as a dietary supplement.
However, he adds, it is still possible that orally administered resveratrol can prevent cancers along the aerodigestive tract. It is also possible that a resveratrol sulfate conjugate detected
Contact: Sarah Goodwin
Federation of American Societies for Experimental Biology