Smoking can damage the vascular system and reduce blood flow to the heart. But, according to a new study carried out by scientists at the University Hospital in Zurich, vitamin C can repair the damage.

The Swiss researchers studied 11 healthy smokers and eight non smokers. Using positronemission tomography (PET) to assess blood flow to the heart, they found that blood flow was 21 per cent lower in the smokers. Subsequent infusion of three grams of vitamin C normalised blood flow to the heart in the smokers, but had no effect in the non smokers.

Reduced blood flow to the heart is thought to be an early sign of damage to the heart because of oxidative stress brought on by smoking. Smoking also reduces the amount of vitamin C in tissues and blood. Thus, in this study, the large amounts of vitamin C administered in a one off dose probably produced a pharmacological antioxidant action rather than restored vitamin C concentrations in these subjects.

Higher intake of antioxidant foods such a fruits and vegetables, say the researchers, is still the best way to prevent such problems in smokers. However, supplemental oral vitamin C may also prove to be therapeutic (Lancet, 2000; 356: 1007).