Objective: Limited data exist from randomized trials evaluating, noninvasively, the impact of antioxidant supplementation on vascular structure and function.
Methods and results: This is a substudy of the SU.VI.MAX Study, which is a randomized, double-blind, placebo-controlled, cardiovascular and cancer primary prevention trial. Eligible participants (free of symptomatic chronic diseases and apparently healthy) were randomly allocated to daily receive either a combination of antioxidants (120 mg vitamin C, 30 mg vitamin E, 6 mg beta carotene, 100 microg selenium, and 20 mg zinc) or placebo and followed-up over an average of 7.2+/-0.3 years. At the end-trial examination, the carotid ultrasound examination and carotid-femoral pulse-wave velocity (PWV) measurement were performed blindly in 1162 subjects aged older than 50 years and living in the Paris area. The percentage of subjects with carotid plaques was higher in the intervention group compared with the placebo group (35.2% versus 29.5%, P=0.04). Common carotid intima-media thickness (mean+/-SD) was not different between the 2 groups (0.70+/-0.08 versus 0.70+/-0.08 mm, P=0.38). Mean PWV tended to be lower (indicating less stiff aortic arteries) in the intervention group but the difference did not reach statistical significance (P=0.13).
Conclusions: These results suggest no beneficial effects of long-term daily low-dose supplementation of antioxidant vitamins and minerals on carotid atherosclerosis and arterial stiffness.