Contrary to previous findings, a new study suggests the antioxidant resveratrol is not associated with improvements in health, including reducing the risk of cancer.
Researchers found that Italians who consumed a diet rich in resveratrol—a compound in red wine, dark chocolate, and berries—lived no longer than and were just as likely to develop cardiovascular disease or cancer as Italians who consumed smaller amounts of the antioxidant.
However, the investigators said unknown compounds in these foods and drinks may still confer health benefits.
“The story of resveratrol turns out to be another case where you get a lot of hype about health benefits that doesn’t stand the test of time,” said study author Richard D. Semba, MD, MPH, of the Johns Hopkins University School of Medicine in Baltimore, Maryland.
“The thinking was that certain foods are good for you because they contain resveratrol. We didn’t find that at all.”
Dr Semba and his colleagues recounted their findings in JAMA Internal Medicine.
Their study included 783 subjects, all of whom were older than 65 years of age. Participants were part of the Aging in the Chianti Region study, conducted from 1998 to 2009 in 2 Italian villages where supplement use is uncommon and the consumption of red wine is the norm. The subjects were not on any prescribed diet.
The researchers wanted to determine if diet-related resveratrol levels were associated with inflammation, cancer, cardiovascular disease, and death. So they collected urine samples from study participants and used advanced mass spectrometry to analyze the samples for metabolites of resveratrol.
After accounting for such factors as age and gender, the investigators found that subjects with the highest concentration of resveratrol metabolites were no less likely to have died of any cause than subjects with the lowest levels of resveratrol in their urine.
Likewise, the concentration of resveratrol was not associated with inflammatory markers (serum CRP, IL-6, IL-1β,TNF), cardiovascular disease, or cancer rates.
During 9 years of follow-up, 268 participants (34.3%) died. From the lowest to the highest quartile of baseline total urinary resveratrol metabolites, the proportion of subjects who died from all causes was 34.4%, 31.6%, 33.5%, and 37.4%, respectively (P=0.67).
Of the 734 participants who were free of cancer at enrollment, 34 (4.6%) developed cancer during follow-up. The proportions of subjects with incident cancer from the lowest to the highest quartiles of resveratrol were 4.4%, 4.9%, 5.0%, and 4.3%, respectively (P=0.98).
Of the 639 subjects who were free of cardiovascular disease at enrollment, 174 (27.2%) developed cardiovascular disease during follow-up. The proportions of participants with incident cardiovascular disease from the lowest to the highest quartiles of resveratrol were 22.3%, 29.6%, 28.4%, and 28.0%, respectively (P=0.44).
Despite these negative results, Dr Semba noted that studies have shown the consumption of red wine, dark chocolate, and berries does reduce inflammation in some people and still appears to protect the heart.
“It’s just that the benefits, if they are there, must come from other polyphenols or substances found in those foodstuffs,” he said. “These are complex foods, and all we really know from our study is that the benefits are probably not due to resveratrol.”
