Scientists at the University of California, Davis, have identified another group of chemicals in red wine that is linked to the ability to lower cholesterol. Called saponins, these glucose-based plant compounds are being found in an increasing number of foods. This is the first time they've been found in wine, says Andrew Waterhouse, Ph.D., Professor of Enology (wine chemistry) at the University of California, Davis.
His finding was described today at the 226th national meeting of the American Chemical Society, the world's largest scientific society.
For the most part, the so-called French Paradox the association between red wine and decreased heart disease has been attributed to resveratrol, a compound found in grapes, which acts as an antioxidant. But saponins could be just as important.
"Saponins are a hot new food ingredient. People are just starting to pay attention to it," says study leader Waterhouse. "No one ever thought to look for it in wine."
The compounds are believed to come from the waxy skin of grapes, which dissolve into the wine during its fermentation process. To better understand their distribution in wine, Waterhouse conducted a preliminary study of six varieties of California wines four red and two white and compared them on the basis of their saponin content.
"Average dietary saponin intake has been estimated at 15 mg, while one glass of red has a total saponin concentration of about half that, making red wine a significant dietary source," the researcher says.
In general, Waterhouse found that red wine contains significantly higher saponin levels than white about three to ten times as much. Among the red wines tested, red Zinfandel contained the highest levels. Syrah had the second highest, followed by