Country Level Incidence of Alzheimer Disease and Related Dementias is Associated with Increased Omega6 PUFA Consumption

INTRODUCTIONClinical 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. METHODSMean 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. RESULTSOmega6 Polyunsaturated-Fatty-Acid(PUFA) intake exhibited a positive linear relationship with ASAIR(multivariable-adjusted model: {beta}=2.44; 95%CI: 1.70, 3.19; p=1.38x10-9). 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. DISCUSSIONDecreasing Omega6-PUFA consumption on the country-level may have substantial benefits in reducing the country-level burden of AD.