Resveratrol is the compound behind red wine’s famous health benefits. And, despite its difficult pronunciation, consumers are finding this word on the tips of their tongues. “There is definitely a growing awareness of the antioxidants found in grapes,” says Matt Seale, sales and marketing, Muscadine Products Corporation, Wray, GA.
Although resveratrol was first isolated in 1940 from the roots of white hellebore, it piqued the interest of scientists when the health benefits of red wine came to light in the “French Paradox,” an observation that the French enjoyed lower rates of mortality from coronary heart disease despite their higher levels of saturated-fat intake and cigarette smoking.
Resveratrol, found in grapes, red wine, purple grape juice, peanuts and some berries, belongs to a class of polyphenolic compounds called stilbenes. Some plants produce resveratrol and other stilbenes in response to stress, injury, fungal infection or ultraviolet radiation. In grapes, resveratrol is only found in the skins, and the amount varies with the grape cultivar, its geographic origin and exposure to fungal infection. The amount of fermentation time a wine spends in touch with its skin also affects resveratrol content; thus, white and rosé wines contain less than red wines. Resveratrol appears to be well-absorbed when taken orally, but its bioavailability is relatively low due to its rapid metabolism and elimination.
Resveratrol’s disease fight
Exploring resveratrol’s potential health properties was a logical step, since both epidemiological and experimental studies had found a heart-health benefit with moderate red wine consumption. Laboratory experiments have since noted antioxidant, anti-inflammatory, anticancer, antiplatelet, cholesterol-lowering and mild estrogenic activities linked with resveratrol. It’s important to note the lack of human research on resveratrol supplementation. Studies also suggest that even high dietary intakes of resveratrol may not result in human tissue levels high enough to see most of the protective effects demonstrated in cell-culture studies.
Ole Vagn, professor,University of Roskilde and scientific advisor to Fluxome Sciences A/S, Lyngby, Denmark, estimates dosage based on animal studies: Based on a single study on hamsters, an effect for humans will be observed using 1 gram resveratrol per day. Based on three rat studies, an effect for humans will be observed using 16 grams resveratrol per day. In a single mouse study, very high doses are used. One liter of red wine has on average 7 mg of trans-resveratrol.