Study Finds Vitamin C Offers Smokers Cardiovascular Benefits

Injections of vitamin C given to smokers reverse one of the most harmful cardiovascular effects of smoking, according to a study being published today.

However, more research is needed to determine whether vitamin C pills might help reduce heart disease associated with cigarettes, said the authors of the study, published in the American Heart Assn. journal Circulation.

The vitamin works because of its antioxidant function, said Dr. Thomas Munzel of the University of Freiburg in Germany, one of the study’s authors.

Cigarette smoke contains powerful oxidants--chemicals that react like oxygen, which rusts iron and makes peeled apples turn brown. High concentrations of vitamin C or vitamin E neutralize oxidants.

The study suggests that in people, oxidants damage the endothelium, a layer of cells that helps arteries narrow and widen. When the endothelium is damaged, plaque forms more easily in the arteries, making people more prone to strokes and heart attacks.

Researchers gave injections of a chemical that stimulates the endothelial cells to 10 nonsmokers and 10 longtime smokers. This caused the nonsmokers’ arteries to widen, but it had a much weaker effect on the smokers.

The researchers then injected vitamin C directly into their bloodstreams and tried the first chemical again. The nonsmokers’ arteries widened as they had before, but now the smokers’ arteries responded equally well.

The process “almost completely reverses endothelial dysfunction in chronic smokers,” the researchers said.

Other scientists cautioned that this does not prove that vitamin C neutralizes the effect of smoking on heart disease.

Another study in which smokers were given vitamin C pills over eight years found no effect on their rate of heart disease, said Eric Rimm, an assistant professor of epidemiology at the Harvard School of Public Health.

“I think vitamin C among smokers is very important,” Rimm said. The new study “does suggest that vitamin C has an acute effect of stopping vascular dysfunction.”

But he cautioned: “It’s too early to make the leap that vitamin C will protect smokers from heart disease.”