Current Nutrition & Food Science · Sep 30, 2026
Exploring the Link Between the Dietary Inflammation Index and Alzheimer’s Disease: Insights from the NHANES Database
By Tong S, Zhang Y, Chen Y et al.
Introduction: To explore this potential association, this study analyzed the relationship between the dietary inflammatory index (DII) and the risk of Alzheimer's disease (AD) using data from a national adult cohort in the United States. Methods: The study was a cross-sectional analysis of 116,876 participants from the National Representative Health and Nutrition Survey (NHANES) 1999-2020. To explore the correlation between DII and AD, we used multivariate logistic regression as the primary analysis method and incorporated complex survey weights from the survey to ensure data accuracy. DII from dietary recalls; AD self-reported. Restricted cubic splines (RCS) and Weighted Quantile Sum (WQS) regression were also employed. Sensitivity analyses with IPTW and subgroup evaluations were conducted. Results: Higher DII quartiles were associated with increased AD odds (fully adjusted OR 1.011, 95% CI excluding 1.0). The RCS model confirmed that the link was nonlinear and gradually increasing. A J-shaped relationship was found, with elevated risk at both low and high DII levels. WQS identified 28 dietary components linked to AD, notably protein, alcohol, selenium, and specific fatty acids. Directional consistency was supported across subgroup, sensitivity, and treatment weighting (IPTW) analyses. Discussion: This is the first evidence of a J-shaped DII-AD association in a large U.S. cohort, suggesting that both extreme anti-inflammatory and pro-inflammatory diets may increase AD risk, underscoring the importance of dietary balance. Key drivers include protein, alcohol, selenium, and fatty acids. Causal inference is limited by cross-sectional design. Conclusions: This study found a J-shaped nonlinear relationship between DII scores and AD in a broad U.S. adult sample, with elevated risk at both low and high DII levels.