Abstract Body: Background: Mediterranean-DASH Intervention for Neurodegeneration Delay (MIND) diet was associated with better cognitive outcomes, but the role of inflammation in this association was rarely explored.
Methods: We included 3777 Health and Retirement Study participants (mean age=65.3 years, 59.0% female) who completed the food frequency questionnaire in 2013 and assayed for 18 inflammatory markers in venous blood in 2016. The inflammatory markers included 5 cytokines and 4 other proteins in serum and 9 blood cell measures. Cognitive function was assessed using the 27-unit modified Telephone Interview of Cognitive Status (TICS-m) in 2016, 2018, and 2020. We used linear regression models to assess the associations of the MIND diet score with inflammatory markers and performed mediation analysis to whether they mediate the MIND-cognitive function association.
Results: During the 7-year follow-up, higher MIND diet score indicating higher compliance to the MIND diet was significantly associated with better cognitive function (beta per 3-unit increment with global cognitive function z-score=0.05, 95% CI: 0.02-0.09). Higher MIND score was also related to lower levels of interleukin-1 receptor antagonist (IL-1RA), IL-6, IL-10, soluble tumor necrosis factor receptor-1 (sTNFR-1), C-reaction protein (CRP), cystatin C, neutrophils, and white blood cell count and higher level of albumin (false discovery rates<0.05). Among them, higher levels of IL-6, IL-10, sTNFR-1, cystatin C, neutrophils, and white blood cell count, and lower level of albumin were inversely associated with cognition in later waves (P-values<0.05 for all). Further, the association of the MIND diet with cognitive function was significantly mediated by cystatin C (11.0%), sTNFR-1 (9.5%), IL-6 (4.6%), white blood cell count (3.6%), and IL-10 (3.3%). Collectively, these markers mediated the MIND-cognition association by 11.8% (p<0.001).
Conclusion: Adherence to the MIND diet is associated with a panel of circulating systemic inflammatory markers that have been extensively investigated in Alzheimer’s disease. These peripheral blood-based biomarkers significantly mediate the MIND-cognition association and may serve as potential targets or intermediate outcomes of dietary intervention for cognitive health.