Hypercholesterolemia, cigarette smoking, hypertension, and obesity are known 
contributing risk factors for the development of atherosclerotic coronary artery 
disease (CAD). However, they account for only half of all cases of CAD, and the 
complete pathologic process underlying atherosclerosis remains unknown. Growing 
evidence suggests that oxidative modification of low-density lipoprotein (LDL) 
may be of particular importance in the pathogenesis. Oxidized LDL exhibits 
proatherogenic effects. Therefore, current research has focused on inhibiting 
the oxidation of LDL as a means of inhibiting the atherosclerotic process. One 
such approach is to enhance the endogenous antioxidant defense systems within 
the LDL particle with lipophilic antioxidants such as alpha-tocopherol and 
beta-carotene, or by supplementing the aqueous-phase antioxidant capacity with 
ascorbic acid. Observational data suggest a protective effect of antioxidant 
supplementation on the incidence of CAD; however, specific doses cannot be 
recommended since the data are inconclusive.