Researchers have found that vitamin C and taurine, an amino acid in fish, reversed abnormal blood vessel response associated with cigarette smoking.

“When blood vessels are exposed to cigarette smoke it causes the vessels to behave like a rigid pipe rather than a flexible tube, thus the vessels can’t dilate in response to increased blood flow,” says David J. Bouchier-Hayes, MD, senior study author. This is a condition called endothelial dysfunction. Endothelial dysfunction is one of the earliest signs of the atherosclerosis, which is a major cause of heart attacks and stroke.

Bouchier-Hayes and colleagues recruited 15 healthy smokers aged 20 to 37 and 15 healthy non-smoking volunteers. The smokers were given either two grams per day of vitamin C for five days or 1.5 grams per day of taurine. Smokers then waited for a two-week “wash-out” period and switched therapies for five more days. After assessing blood vessel function before and after supplementation, the researchers found that taurine restored normal vessel function. When they took vitamin C, smokers’ vessel diameter increased, allowing for healthier blood flow.

Taurine is found in many foods but is most abundant in fish, says Bouchier-Hayes, who adds that taurine is present even in mild, white fish, so not just fatty fish. The taurine supplement used in the study is equivalent to that found in one serving of fish.

“We’re not trying to find a therapeutic treatment for smoking, because we believe that the best therapy for smokers is to stop smoking,” says Bouchier-Hayes. “Nonetheless, smokers provide a good clinical model for treatment of endothelial dysfunction.”

American Heart Association, Jan 7, 2003