A new study carried out on a large group of Italians found that a diet rich in resveratrol, a polyphenol found in red wine, chocolate and certain berries, was not associated with a reduction in the incidence of cancer, cardiovascular disease or death. Furthermore, resveratrol levels achieved from the diet did not substantially influence the health status of the participants. The study has been published in JAMA Internal Medicine.
There has been a lot of hype over resveratrol in the last few years. Numerous studies have popped up demonstrating how this compound, which is found in relatively high levels in grapes, peanuts and certain Asiatic plant roots, may have antioxidant, anti-inflammatory and anticancer properties. Mice studies have also shown that it may promote longevity and health in those fed a high-calorie diet.
Regular consumption of polyphenols from red wine, in particular resveratrol, is also thought to responsible for the “French paradox”, where a low incidence of coronary heart disease is apparent within those consuming a diet high in cholesterol and saturated fat in France. Consequently, individuals spend around $30 million in the U.S. each year on resveratrol supplements. But is resveratrol really the wonder compound it’s cracked up to be? Previous human studies have fallen short because they have focused on high doses of resveratrol as opposed to levels achievable by diet alone, which is where this study comes in.
Researchers, led by Dr. Richard D. Semba of Johns Hopkins University School of Medicine, used data collected from a cohort study conducted on 783 men and women, aged 65 or older, between 1998 and 2009 which set out to investigate aging in individuals from the Chianti region of Italy. The randomly selected participants of the study were not on any prescribed diet, regularly consumed red wine and rarely took supplements.
In addition to this data, the team also analyzed 24 hour urine samples taken from the individuals to look for resveratrol breakdown products (metabolites) via mass spectrometry. This is because directly studying resveratrol levels is difficult due to the swift uptake, metabolism and excretion of the compound by the body. Urinary resveratrol metabolites have also been previously demonstrated to be a valid marker of wine consumption.
The researchers used this data to look for associations between resveratrol metabolite levels and mortality, inflammatory markers and incidence/prevalence of cancer and cardiovascular disease. Intriguingly, after accounting for factors such as age and gender, they found no association between resveratrol levels and any of these outcome measures. The team concluded “Resveratrol levels achieved within a Western diet did not have a substantial influence on health status and mortality risk of the population in this study.”
Of course, this doesn’t mean that we should allow all of those delicious bottles of red wine to gather dust on the shelves. According to Semba, other studies have demonstrated that consuming red wine, dark chocolate and berries does reduce inflammation in some individuals and seems 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 adds. “These are complex foods, and all we really know from our study is that the benefits are probably not due to resveratrol.”