Updated

Resveratrol — the red wine compound often touted for its possible healthful and anti-aging effects — may not bring the benefits to healthy people that preliminary research has suggested, a small new study finds.

In the 12-week study, 29 healthy women, most of them in their late 50s, were given either resveratrol supplements or a placebo. No appreciable differences were found after the 12 weeks between the two groups in regard to body fat, resting metabolic rate, fat levels in the blood, or markers of inflammation.

"Our data demonstrate that resveratrol supplementation does not have metabolic benefits in relatively healthy middle-aged women," study researcher Dr. Samuel Klein, director of the Center for Human Nutrition at Washington University in St. Louis, said in a statement.

People with metabolic problems did not take part in the study, and it is still possible resveratrol might benefit them, Klein noted.

Although annual sales of resveratrol supplements in the U.S. have risen to $30 million, "few studies have evaluated the effects of resveratrol in people," Klein said. The supplements' popularity may be due to studies on animals and cells growing in lab dishes, which have suggested resveratrol improves metabolism or could prevent or reverse chronic health problems such as diabetes and heart disease, he said.

Fifteen of the post-menopausal women in the study took 75-milligram supplements of resveratrol daily — equivalent to the amount they'd get from drinking eight liters of red wine. The other 14 took a placebo pill.

It's not surprising that the study did not find any effect from a mere 75-milligram daily dose, said Dr. Jay Chung, chief of the Laboratory of Obesity and Aging Research at the National Heart, Lung, and Blood Institute, who was not involved in the new study.

Studies showing beneficial metabolic effects of resveratrol have used higher doses, of 150 mg to 2,000 mg day, Chung told MyHealthNewsDaily.

However, he said, "In my opinion, resveratrol is highly unlikely to have any benefits in metabolically healthy individuals."

In people with glucose intolerance — a "pre-diabetes" condition in which a person's blood sugar levels are high but not high enough to warrant a diagnosis of Type 2 diabetes — it's possible that high doses of the compound may have an effect, Chung said, but treatments such as the diabetes drug metformin are a much safer and more effective option. The long-term effects of high doses of resveratrol are not known, he added.

The study is published today (Oct. 25) in the journal Cell Metabolism.

Pass it on: A much-touted compound in red wine showed no metabolic benefits for healthy middle-age women in a small study.