Vitamin E and Alzheimer's disease in subjects with Down's syndrome

. People with Down's syndrome (DS) are at high risk of developing Alzheimer's disease (AD). The gene coding for Superoxide dismutase-/ on chromosome 21 resulting in excess activity of the enzyme with consequent risk of oxidative damage might account for the premature ageing. Vitamin E protects against such damage. Plasma vitamin E levels measured in 12 DS subjects with AD (8.19·0.77 μg/ml) were lower (P<0.05) than in 12 DS controls (9.43·1.57 μg/ml). It is suggested that there may be an interaction between risk of AD and the protective action of vitamin E.