The lower incidence of heart disease in France, despite a diet rich in butter and other fats, has led researchers to look to the consumption of red wine, another staple of the French diet. Scientists say they have discovered the key component in red wine. The explanation is pigments known as polyphenols.
Polyphenols inhibit the production of a peptide that contributes to hardening of the arteries. Polyphenols in red wine decreases the amount of the peptide endothelin-1 produced by cells taken from the blood vessels of cows. Endothelin-1 is a potent blood vessel constrictor, and overproduction of the compound is thought to be a key factor in why arteries clog with fatty deposits. The pigments are not present in white wine or rose, and they seem to be less potent when they are present in grape juice.
In the study, the cow cells were exposed to extracts from 23 red wines, four white wines, one rose and one type of red grape juice. Researchers found the decrease in endothelin-1 levels was related to the amount of polyphenols in the wines.
The white and rose wines -- which contain little or none of the pigment -- had no effect on endothelin-1 levels. Red grape juice, which has plenty of the pigment, was markedly less potent in reducing endothelin-1 than red wine.
The researchers said that something in the winemaking process changes the pigment's properties. Researchers believe the pigment comes from red wine skins. In white wine and rose, the grape skins are taken out before fermentation. The key message is moderate consumption of red wine is likely to prevent heart disease.