Effect of Antioxidant Vitamins on the Transient Impairment of Endothelium—Dependent Brachial Artery Vasoactivity Following a Single High-Fat Meal

Abstract

Context. —Much has been written about the potential role of antioxidants in the prevention of atherosclerosis. Objective. —To assess the short-term effect of a single high-fat meal with and without pretreatment with antioxidant vitamins on endothelial function in healthy, normocholesterolemic subjects. Design. —Observer-blinded randomized trial. Setting. —University hospital. Participants. —Twenty healthy, normocholesterolemic (total and low-density lipoprotein cholesterol P<.001). No significant changes in flow-mediated vasodilation occurred after the low-fat meal, high-fat meal with vitamins, or low-fat meal with vitamins. The change in flow-mediated vasodilation after the low-fat and high-fat meals correlated inversely with the 2-hour postprandial change in triglyceride levels (r=-0.54;P<.001). Conclusion. —A single high-fat meal transiently reduces endothelial function for up to 4 hours in healthy, normocholesterolemic subjects, probably through the accumulation of triglyceride-rich lipoproteins. This decrease is blocked by pretreatment with antioxidant vitamins C and E, suggesting an oxidative mechanism.