Source: American Journal of Clinical Nutrition, October 2006;84(4):880-887.
Research: Laboratory and observational studies suggest that antioxidant and B vitamin supplementation may prevent atherosclerosis. Although trials have not shown a benefit of these supplements on clinical cardiovascular events, research-ers believe it is unknown whether they affect the progression of atherosclerosis as measured by imaging techniques. This is why researchers undertook a meta-analysis of randomized-controlled trials to assess the effect of vitamin/mineral supplementation on atherosclerosis progression. Researchers separately analyzed trials using antioxidants and trials using B vitamins. The progression of atherosclerosis was evaluated by B-mode ultrasound, intravascular ultrasound or angiography. Effect sizes were calculated for the difference in slope of atherosclerosis progression between participants assigned to supplements and those assigned to the control group.
Results: The meta-analysis showed no evidence of a protective effect for antioxidants or for B vitamin supplements on the progression of atherosclerosis, thus providing a mechanistic explanation for their lack of effect on clinical cardiovascular events.