Although long considered a veritable silver bullet when it comes to preventing health problems, a new study calls into question the superpowers of the antioxidant resveratrol.
According to the recent research, diets high in the compound -- found in red wine, grapes and chocolate -- showed no significant decrease in heart disease, cancer or death.
To examine the long-term impact of resveratrol, researchers looked to the longitudinal "Aging in the Chianti Region" study. They examined the compound's presence in urine samples from 783 healthy men and women, 65 years old or older, living in two Italian villages within the Chianti region. The researchers were confident that their measure would accurately reflect resveratrol from food and drink sources, since supplement use is unusual in this region, while regular red wine consumption is common.
The researchers cross-referenced resveratrol concentration in a participant's urine with their likelihood of either dying or developing heart disease or cancer within the 11-year study period -- from 1998 to 2009. Within that time, 27.2 percent of participants developed heart disease and nearly 5 percent developed cancer. More than a third of participants -- 34.3 percent -- died during the period of study.
After controlling for age, gender and other potentially confounding factors, the researchers found that people with high concentrations of resveratrol in urine samples were no less likely to have died, developed heart disease or cancer or have inflammatory markers than people with no resveratrol. "This study suggests that dietary resveratrol from Western diets in community-dwelling older adults does not have a substantial influence on inflammation, cardiovascular disease, cancer, or longevity," the authors wrote.
"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," lead study author Dr. Richard D. Semba, M.D., MPH, a professor of ophthalmology at the Johns Hopkins University School of Medicine, said in a statement. "The thinking was that certain foods are good for you because they contain resveratrol. We didn't find that at all."
Previous research has had mixed results. One recent study found that resveratrol extended the lifespan of fat mice -- but not lean ones. Others have cast doubt that resveratrol is still active in the body after it's converted during digestion or questioned how much red wine one would have to drink to actually reap any benefits.
That doesn't mean the heralded benefits of chocolate or wine are all a wash. It's likely they come from other compounds that have yet to be identified instead, Semba said in a statement. "These are complex foods, and all we really know from our study is that the benefits are probably not due to resveratrol."
It's clear that we simply don't know enough. "Although annual sales of resveratrol supplements have reached $30 million in the United States alone," the authors wrote, "there is limited and conflicting human clinical data demonstrating any metabolic benefits of resveratrol."