Abstract

There is clear evidence of lipoprotein oxidation in atherosclerotic lesions. Animal studies and observational prospective human cohort studies have been interpreted as supporting a role for antioxidants in the prevention of coronary heart disease (CHD). However, firm recommendations to take antioxidant supplements to treat or prevent CHD require evidence derived from randomised controlled studies. In primary prevention studies, low dose alpha-tocopherol does not reduce the incidence of coronary events (ATBC study), and beta-carotene either has no effect or increases the incidence of coronary events and cancer death (ATBC, CARET, Physician's Health studies). Secondary preventions, those with smaller populations and shorter duration of follow up have shown some benefit from alpha-tocopherol (CHAOS, SPACE), but larger randomised studies indicate no benefit from treatment with alpha-tocopherol (HOPE, GISSI, PPP). Recent studies with antioxidant combinations also show no benefit (HATS, MPS). On the basis of these data, supplements of alpha-tocopherol and beta-carotene cannot be recommended for the treatment or prevention of CHD. Fundamental and applied research may yet find a role for antioxidant supplements in the treatment of coronary disease. However, this will require positive results from combined antioxidant studies currently in progress, and the targeting of oxidative processes that operate in the artery wall and cause or contribute to disease.