Effects of antioxidants on vascular health

Substantial in vitro and animal model evidence implicates the free radical-mediated oxidation of low density lipoprotein and its subsequent preferential uptake by macrophages in the arterial intima as an important factor in the development of vascular disease. In addition, antioxidants which prevent the oxidation of LDL in vitro also reduce the severity of vascular disease in animal models. Although some epidemiological studies also suggest that inadequate antioxidant status is related to the development of vascular disease, particularly cardiovascular disease, results from intervention trials have been contradictory. Whereas vitamin E may have a role in reducing the incidence of vascular disease, evidence is less strong for vitamin C, flavonoids and beta-carotene. Additionally, supplementation with some antioxidants such as beta-carotene may increase the incidence of cancer in high risk groups. Although increasing antioxidant intake is generally beneficial for health, this should perhaps be achieved by an increased dietary intake of antioxidant-rich foods rather than by use of supplements.