Resveratrol, a chemical found in red wine and dark chocolate, may work differently in the body than first thought, a new study suggests.

"Resveratrol has potential as a therapy for diverse diseases such as Type 2 diabetes, Alzheimer's disease,  and heart disease," said lead study author Dr. Jay Chung, chief of the National Heart, Lung and Blood Institute's laboratory of obesity and aging research in Bethseda, Md.

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People would need to drink about 667 bottles of red wine to get a meaningful treatment dose of resveratrol, a researcher says. (Remy de la Mauviniere/Associated Press)

"However, before researchers can transform resveratrol into a safe and effective medicine, they need to know exactly what it targets in cells," he added in a release.

To that end, Chung and his co-authors traced how the chemical interacts in cells and did follow-up tests in mice.

They were able to track resveratrol's many interactions in a cell to understand which ones were responsible for the benefits.

Resveratrol appears to inhibit proteins called phosphodiesterases (PDEs), which help regulate cell energy, the researchers said.

Based on studies in yeast, scientists had thought that resveratrol's main target was another protein called sirtuin 1, but increasing levels of that protein in mice didn't extend their lifespan as predicted, casting doubts on that theory.

Resveratrol isn't ready to try as a medicine, Chung cautioned. Since it interacts with so many proteins, it could cause problems that haven't yet been discovered. 

He estimated people would need to drink about 667 bottles of red wine to get a meaningful treatment dose of resveratrol.

The study appears in Friday's issue of the journal Cell.