Introduction: Clinical and genetic studies have implicated lipid dysfunction in Alzheimer Disease (AD) pathogenesis. However, lipid consumption at the individual-level does not vary greatly within most cohorts, and multiple lipids are rarely measured in any one study.
Methods: Mean country-level lipid intakes were compared to Age-Standardized Alzheimer-Disease-Incidence-Rates(ASAIR) in 183 countries across all inhabited continents. Penalized spline regression and multivariable-adjusted linear regression, including a lag between intake and incidence, were used to assess the relationships between five lipid intakes and ASAIR. Validation was conducted using longitudinal within-country changes between 1990 and 2019.
Results: Omega6 Polyunsaturated-Fatty-Acid(PUFA) intake exhibited a positive linear relationship with ASAIR(multivariable-adjusted model: β=2.44; 95%CI: 1.70, 3.19; p=1.38×10-9). ASAIR also increased with saturated-fat, trans-fat, and dietary-cholesterol up to a threshold. The association between Omega6-PUFA and ASAIR was confirmed using longitudinal intake changes.
Discussion: Decreasing Omega6-PUFA consumption on the country-level may have substantial benefits in reducing the country-level burden of AD.
Keywords: Alzheimer’s disease; dementia; diet; epidemiology; lipids; population health; prevention.