RESUMO
OBJECTIVE: The widely reported associations between various nutrients and cognition may occur through many biologic pathways including those of ß-amyloid (Aß). However, little is known about the possible associations of dietary factors with plasma Aß40 or Aß42. The aim of the current study was to evaluate the association between nutrient intake and plasma Aß levels. METHODS: In this cross-sectional study, plasma Aß40 and Aß42 and dietary data were obtained from 1,219 cognitively healthy elderly (age >65 years), who were participants in a community-based multiethnic cohort. Information on dietary intake was obtained 1.2 years, on average, before Aß assay. The associations of plasma Aß40 and Aß42 levels and dietary intake of 10 nutrients were examined using linear regression models, adjusted for age, gender, ethnicity, education, caloric intake, apolipoprotein E genotype, and recruitment wave. Nutrients examined included saturated fatty acid, monounsaturated fatty acid, ω-3 polyunsaturated fatty acid (PUFA), ω-6 PUFA, vitamin E, vitamin C, ß-carotene, vitamin B(12), folate, and vitamin D. RESULTS: In unadjusted models that simultaneously included all nutrients, higher intake of ω-3 PUFA was associated with lower levels of Aß40 (ß = -24.7, p < 0.001) and lower levels of Aß42 (ß = -12.3, p < 0.001). In adjusted models, ω-3 PUFA remained a strong predictor of Aß42 (ß = -7.31, p = 0.02), whereas its association with Aß40 was attenuated (ß = -11.96, p = 0.06). Other nutrients were not associated with plasma Aß levels. CONCLUSIONS: Our data suggest that higher dietary intake of ω-3 PUFA is associated with lower plasma levels of Aß42, a profile linked with reduced risk of incident AD and slower cognitive decline in our cohort.