Resveratrol — an antioxidant found in foods and drinks such as red wine, chocolate and grapes — has been purported to have anti-aging effects, but a new study suggests the compound may not help people live longer after all.
In the study of about 800 older adults in Italy, people who ate a resveratrol-rich diet were just as likely to die over a nine-year period, compared with those who consumed small amounts of the compound.
In addition, consuming high amounts of resveratrol was not linked with a reduced risk of heart disease or cancer. [7 Ways Alcohol Affects Your Health]
Resveratrol has been shown to reduce inflammation in animal studies as well as increase the life span of mice. And in people, it has been suggested that consuming high levels of resveratrol through supplements might reduce cholesterol levels and have other heart and anti-cancer benefits. But few studies have looked at whether resveratrol has benefits at the levels typically found in the human diet.
"The thinking was that certain foods are good for you because they contain resveratrol," study researcher Dr. Richard Semba, of the Johns Hopkins University School of Medicine, said in a statement. "We didn't find that at all."
But red wine, dark chocolate and grapes may still be good for the heart and have other benefits, Semba said. However, the benefits may not be due to resveratrol, he added.
The study involved 783 adults ages 65 and older living in the Chianti region of Italy, where consumption of red wine is common. At the study's start, participants gave urine samples over a 24-hour period, which were then analyzed for resveratrol metabolites, or break-down products. Participants were divided into four groups based on the amount of resveratrol metabolites in their urine.
During the nine years over which the participants were followed, 268 died. Participants from each of the four resveratrol groups were equally likely to die during the study (about a third in each group).
The findings suggest that resveratrol alone may not have health benefits, so taking resveratrol supplements "might not be worth it," said Dr. Suzanne Steinbaum, a preventive cardiologist at Lenox Hill Hospital in New York, who was not involved in the study.
However, red wine, dark chocolate and berries can still be part of a heart-healthy diet, because they contain other antioxidant compounds, known as bioflavonoids, that have been shown to decrease inflammation and blood clotting, Steinbaum said.
Being heart-healthy is about the big picture, and not a "magic pill," she said.
The study is published online today (May 12) in the journal JAMA Internal Medicine.