Nutrient intake and plasma beta-amyloid Neurology

1) An important pathological hallmark of Alzheimer disease (AD) is B-amyloid (AB) peptide (mainly AB40 and AB42) deposition in the brain, resulting in formation of plaques. 2) It is not easy or practical to measure brain AB levels, but plasma AB is easy to obtain and minimally invasive. 3) These authors examined whether dietary intake of nutrients was associated with plasma AB levels in a cross-sectional analysis of 1,219 persons 65 years or older. Participants were in a community based multiethnic cohort. 4) Plasma levels of AB were measured and analyzed against stringent and comprehensive nutrient and supplement data collection. 5) The associations of plasma AB40 and AB42 levels and dietary intake of 10nutrients were examined using linear regression models, adjusted for age, gender,ethnicity, education, caloric intake, apolipoprotein E genotype, and recruitmentwave. 6) Nutrients examined included saturated fatty acid, monounsaturated fatty acid,omega-3 polyunsaturated fatty acid (PUFA), omega-6 PUFA, vitamin E, vitamin C,beta-carotene, vitamin B12, folate, and vitamin D. 7) Higher intake of omega-3 PUFA was associated with lower levels of AB40(24.7% reduced risk) and lower levels of AB42 (12.3% reduced risk). [Total ABreduced risk of 37%] 8) Other nutrients were not associated with plasma AB levels. 9) Our data suggest that higher dietary intake of omega-3 PUFA is associatedwith lower plasma levels of AB42, a profile linked with reduced risk of incident ADand slower cognitive decline in our cohort. 10) There is increasing evidence to suggest that diet may play an important rolein preventing or delaying the onset of Alzheimer disease.