Dietary inflammatory index and Alzheimer's disease mortality in a prospective cohort

OBJECTIVE: This study examined the relationship between the Dietary Inflammatory Index (DII) and Alzheimer's disease (AD) mortality in US adults. METHODS: Data from 45,093 participants in the 1988-2014 National Health and Nutrition Examination Survey (NHANES) were analyzed, with mortality follow-up through December 2019. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs) for AD mortality. Restricted cubic spline analysis explored the non-linear association of DII with AD mortality, and stratified analyses identified higher-risk subgroups. RESULTS: Over a median follow-up of 14.3 years, 455 AD-related deaths occurred. Participants in the highest DII quartile (>2.41) had a 1.50-fold increased risk of AD mortality (95 % CI: 1.12-2.01) compared to the lowest quartile (≤-0.44). Pro-inflammatory diets (DII > 0) were associated with a 44 % higher risk of AD mortality (HR: 1.44, 95 % CI: 1.14-1.81). A dose-response relationship was observed, with increased risks across quartiles, and findings were consistent across demographic and clinical subgroups. CONCLUSIONS: Higher DII levels were significantly associated with elevated AD mortality risk, highlighting the potential role of pro-inflammatory diets in AD-related outcomes.