Erythrocyte omega-3 index, ambient fine particle exposure and brain aging

Objective: To examine whether LCn3PUFA levels modify the potential neurotoxic effects of PM2.5 exposure on normal-appearing brain volumes among dementia-free elderly women. Methods: A total of 1,315 women (aged 65 to 80 years) free of dementia were enrolled in an observational study between 1996-9 and underwent structural brain MRI in 2005-6. Based on prospectively collected and geocoded participant addresses, we used a spatiotemporal model to estimate the 3-year average PM2.5 exposure before the MRI. We examined the joint associations of baseline LCn3PUFAs in red blood cells (RBCs) and PM2.5 exposure with brain volumes in generalized linear models. Results: After adjustment for potential confounders, participants with higher levels of RBC LCn3PUFA had significantly greater volumes of white matter and hippocampus. For each inter-quartile increment (2.02%) in omega-3 index, the average volume was 5.03 cm3 (P Conclusions: Findings from this prospective cohort study among elderly women suggest that the benefits of LCn3PUFAs on brain aging may include the protection against potential adverse effects of air pollution on white matter volumes.