Resveratrol, a polyphenol found in grapes, red wine, chocolate, and certain berries and roots, is considered to have antioxidant, anti-inflammatory, and anticancer effects in humans and is related to longevity.
Dr. Richard D. Semba, MD, MA, MPH, the inaugural W. Richard Green Professor of Ophthalmology at the Wilmer Eye Institute, The Johns Hopkins School of Medicine and lead author of this study in which researchers set out to determine whether resveratrol levels achieved with diet are associated with inflammation, cancer, cardiovascular disease, and mortality in humans.
Dr. Semba is part of an international team of researchers that for 15 years has studied the effects of aging in a group of people who live in the Chianti region of Italy.
In this prospective cohort study, the Invecchiare in Chianti (InCHIANTI) Study (“Aging in the Chianti Region”), 1998 to 2009 conducted in 2 villages in the Chianti area in a population-based sample of 783 community-dwelling men and women 65 years or older.
In this study researchers analyzed 24 hour urine samples for metabolites of resveratrol. Resveratrol metabolites are primarily detected upon oral exposure to trans-resveratrol, the active form of Resveratrol polyphenols found in the skins, seeds and stems of red wine grapes,
Researcher’s primary outcome measure was all-cause mortality and secondary outcomes were markers of inflammation, and prevalent and incident cancer and cardiovascular disease. The primary outcome is the outcome of greatest importance. Data on secondary outcomes are used to evaluate additional effects of the intervention.
The results showed an average total of urinary resveratrol metabolite concentrations of 7.08 nmol/g of creatinine.
During the nine year follow-up 268 (34.3%) of the participants died. After accounting for such factors as age and gender, the results showed the proportion of participants who died from all causes from the lowest to the highest concentration of resveratrol metabolites were34.4%, 31.6%, 33.5%, and 37.4%, respectively. Participants with the highest concentration of resveratrol metabolites were no less likely to have died of any cause than those with no resveratrol found in their urine. Resveratrol levels were not significantly associated with inflammatory markers, prevalent or incident cardiovascular disease, or cancer.
The researchers write “In older community-dwelling adults, total urinary resveratrol metabolite concentration was not associated with inflammatory markers, cardiovascular disease, or cancer or predictive of all-cause mortality. Resveratrol levels achieved with a Western diet did not have a substantial influence on health status and mortality risk of the population in this study.”
This study did not include people taking resveratrol supplements, and few studies thus far have found benefits associated with them.
According to Dr. Semba, "The thinking was that certain foods are good for you because they contain resveratrol. We didn't find that at all."
Regardless of the negative results Dr. Semba noted studies have shown that consumption of red wine, dark chocolate and berries does reduce inflammation in some people and still appears to protect the heart. Dr. Semba commented "It's just that the benefits, if they are there, must come from other polyphenols or substances found in those foodstuffs.” "These are complex foods, and all we really know from our study is that the benefits are probably not due to resveratrol."
The so-called "French paradox," in which a low incidence of coronary heart disease occurs in the presence of a high dietary intake of cholesterol and saturated fat in France, has been attributed to the regular consumption of resveratrol and other polyphenols found in red wine.
This study is published ONLINE FIRST in the JAMA Internal Medicine,