New research clarifies red wine's benefits

Researchers are homing in on how a glass of red wine can offer more than just holiday cheer, but also protection against heart disease, according to a study out today.

That report, which appears in the journal Nature, shines light on a natural chemical in red wine that may protect against clogged arteries.

The findings may help explain a scientific mystery dubbed the "French paradox." Scientists had always wondered why the French have had a relatively low rate of heart disease, despite a diet that often includes rich foods laden with artery-clogging fat.

Roger Corder of the Queen Mary School of Medicine in London focused on flavor compounds in red wine called polyphenols, which had previously been credited with red wine's heart benefit.

In this study, the team doused cow cells growing in lab dishes with polyphenols taken from popular merlots, cabernet sauvignons and other red wines. The team found that polyphenols taken from all of the red wines tested slowed the test-tube production of endothelin-1. This natural chemical may help clog arteries by triggering the growth of smooth muscle cells in the artery wall, a process that leads to fatty deposits.

The findings suggest that people who drink a glass or two of red wine a day get less production of endothelin-1, Corder says.

The researchers found that all the red wines offered the endothelin-1 benefit, but cabernet sauvignon appeared to provide a slight edge.

Red grape juice also slowed the production of endothelin-1, but it wasn't as potent as the red wines, Corder says.

The white and rosé wines the team tested had no effect.

Other studies have shown that drinking red wine may boost the blood levels of HDL cholesterol, the good cholesterol. This is the first study suggesting that red wine's benefit may have something to do with endothelin-1, Corder says.

People who already drink wine might want to consider switching to red wine to get some of the heart benefits, Corder says. Others agree with that, but add a warning about alcohol's downside.

Ira Goldberg, a spokesman for the American Heart Association, says it's easy for people to go overboard on alcohol consumption, which can cause many problems, including liver disease.