Vitamin C improve smokers' blood circulation

A dose of vitamin C may boost the poorer-than-average blood circulation in healthy young smokers.In a recent study of 25 healthy men, researchers from the Chiba University Graduate School of Medicine, Japan, found that smokers had a better blood flow to the heart after taking a dose of 2 grams of vitamin C. Shortly after taking the vitamin, 13 smokers showed blood circulation on par with that of the 12 non-smokers. Vitamin C is a potent antioxidant, a substance that helps clear the body of cell-damaging molecules called oxygen free radicals. It is because of this, that the vitamin may counter the oxidative stress put by smoking on the lining of the blood vessels, a mechanism by which smoking leads to artery disease.

The new study looked at the effect of oral vitamin C on coronary flow velocity reserve (CFVR), a measure of how well the blood flow speeds up to help the heart when it's under high demands. Past research has shown that smokers show poorer blood-vessel dilation in response to blood flow and have a diminished CFVR. The investigating team used a non-invasive ultrasound technique to measure CFVR in smokers and non-smokers, before and after they took vitamin C. They found that before taking the vitamin, smokers had a lower CFVR than non-smokers did. Two and four hours after the dose of vitamin C, however, the smokers' average CFVR was restored to a more-normal level.

Though the men in the study were given a large dose of vitamin C, researchers pointed out that it's useless to take doses beyond 200 milligrams, because the body will excrete the excess. Moreover, it's not clear that loading up on vitamin C can benefit smokers. Some trials have found that taking vitamin C supplements does not improve smokers' blood vessel function, at least in the short term.
Lest smokers think they can undo heart damage by chasing a cigarette with a vitamin C pill, the researchers say that the clear message from the results is that smokers need to quit.

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