Oxidative stress and lipid peroxidation have been implicated in the pathogenesis of various diseases, including atherosclerosis and fatty liver diseases, and consequently the role of antioxidants in the prevention and treatment of such diseases has received much attention. In particular, the effects of vitamin E, the most important lipophilic radical-scavenging antioxidant, have been investigated extensively. Many in vitro, animal, and epidemiological studies have reported positive results, but large-scale randomized controlled intervention studies and meta-analyses have produced inconsistent and often disappointing results. In the present review article, the role and action of vitamin E are discussed, with consideration of the factors that determine the outcome of vitamin E treatment. Vitamin E should benefit subjects experiencing oxidative stress due to free radicals when administered at the correct time and for an appropriate duration.
Animals ; Antioxidants/adverse effects/*therapeutic use ; Humans ; Lipid Peroxidation/*drug effects ; Oxidative Stress/*drug effects ; Reactive Oxygen Species/*metabolism ; Vitamin E/adverse effects/*therapeutic use