Researchers say they have discovered the key component in red wine that explains the so-called French Paradox, or the way the French can eat cheeses, buttery sauces and other rich foods and still suffer less heart disease than Americans.
The explanation is pigments known as polyphenols.
Polyphenols inhibit the production of a peptide that contributes to hardening of the arteries, researchers report in today's issue of the journal Nature.
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, said the researchers from the William Harvey Research Institute at the London School of Medicine & Dentistry.
In the study, 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.