SYDNEY, Australia--Vitamin E's efficacy in preventing atherosclerosis appears to be modest and primarily associated with cases of vitamin E deficiency, according to researchers from the University of New South Wales (Free Radic Biol Med, 41, 5:722-30, 2006). Researchers using apolipoprotein E gene deficient (Apoe(-/-)) mice confirmed that vitamin E deficiency caused by disrupting the alpha-tocopherol transfer protein gene (Ttpa) in these mice increased their risk of atherosclerosis. In addition, supplying dietary alpha-tocopherol supplements to Ttpa(-/-) mice restored circulating and aortic levels of alpha-tocopherol and decreased atherosclerosis in the aortic root to the same level as in control Apoe(-/-) mice. However, supplementation did not decrease atherosclerosis risk in the non-deficient animals. In addition, differences in atherosclerosis were not associated with changes in peroxides nor were they reflected in a resistance of plasma lipids to ex vivo oxidation. The researchers concluded vitamin E appears to have a modest impact on atherosclerosis, primarily by addressing deficiency states, and works independently of lipid oxidation in the vessel wall.