LONDON, UNITED KINGDOM. It is well established that smoking is an important risk factor for heart disease and, of course, lung cancer. There is evidence that smoking interferes with blood circulation in both coronary and peripheral arteries. A team of British and Swiss researchers now report that smoking also affects blood circulation (microcirculation) within the heart itself. Their study involved eight healthy male non-smokers (controls) and eleven long-term smokers with no signs of heart disease. The researchers used positron emission tomography (PET scanning) to measure the coronary flow reserve of the smokers and non-smokers before and after the infusion of three grams of vitamin C (ascorbic acid). Coronary flow reserve (CFR) is the ratio between maximal blood flow within the heart and blood flow at rest. A high coronary flow reserve is beneficial. The researchers found that the smokers had an average 21 per cent lower CFR than the controls, but that the vitamin C infusion corrected the deficiency and brought the CFR in the smokers back to the level of the non-smokers. The vitamin C infusion had no effect on the CFR of the non-smokers. The researchers conclude that their results support the hypothesis that the damaging effects of smoking is at least partially caused by excessive oxidative stress. They suggest that it may be worthwhile to undertake a large-scale trial to see if daily oral supplementation with vitamin C can prevent the development of coronary artery disease in smokers.
Kaufmann, Philipp A., et al. Coronary heart disease in smokers: vitamin C restores coronary microcirculatory function. Circulation, Vol. 102, September 12, 2000, pp. 1233-38 [59 references]