Resveratrol, an antioxidant compound found in chocolate and red wine, may not possess the health benefits some have espoused, a new analysis says.

Despite claims of health improvement, the study found diets with high levels of the antioxidant, also found in grapes, brought no significant lowering of rates of cancer, heart disease or death, the researchers said.

An 11-year study in Italy's Chianti region, where regular consumption of red wind is the norm, determined that people carrying significant concentrations in their systems of resveratrol proved no less prone to dying or developing cancer or heart disease than those with no measurable resveratrol, they said.

The study involved almost a thousand people aged 65 or older who participated in an Aging in the Chianti Region study between 1998 and 2009.

"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 researchers said in reporting their study.

"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 author Dr. Richard Semba at the School of Medicine of Johns Hopkins University says.

However, the researchers emphasize that the study does not necessarily show resveratrol is not an effective antioxidant, or that antioxidants don't have a health benefit.

Rather, they suggest, we shouldn't look to one single food source or one single food ingredient as a cure-all for what ails us.

"I don't think the study casts any negative light on red wine or chocolate," Semba says. "What it really says is that food is much more complex, and wine is much more complex than trying to attribute health effects to a single thing such as resveratrol."

The benefits to health of chocolate and wine are likely as much due to other kinds of compounds that remain to be detected and identified, he says.

That's not going to go down well with the diet supplements business, the researchers acknowledge.

"Although annual sales of resveratrol supplements have reached $30 million in the United States alone," the researchers wrote, "there is limited and conflicting human clinical data demonstrating any metabolic benefits of resveratrol."

The study has been published in the online edition of JAMA Internal Medicine.