Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegeneration Delay (MIND) Diet, Circulating Inflammatory Biomarkers, and Cognitive Function: A Prospective Study

Mediterranean-DASH Intervention for Neurodegeneration Delay (MIND) diet was associated with better cognitive outcomes, but the role of inflammation in these associations was elusive. We aimed to assess the association between MIND diet and inflammatory biomarkers and to investigate their mediating roles in the MIND diet-cognition association. We included 3,777 participants from the Health and Retirement Study (mean age = 65.3 years, 59.0% female) who had complete data on food frequency questionnaire in 2013 and 18 circulating inflammatory biomarkers in 2016. MIND diet scores (range: 0-15) were constructed based on consumption levels of 15 food groups. Cognitive function was repeatedly assessed using the 27-unit modified Telephone Interview of Cognitive Status in 2016, 2018, and 2020. We used linear regression to assess the associations between MIND diet scores, inflammatory markers, and cognitive function and evaluate the mediation effects of the inflammatory markers on the MIND-cognition association. During the seven-year follow-up, a higher MIND score was 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, cystatin C, neutrophils, and white blood cell count and a higher level of albumin. Among them, cystatin C (11.6%), sTNFR-1 (10.3%), IL-6 (5.0%), white blood cell count (3.7%), and IL-10 (3.6%) significantly mediated the association of MIND diet with cognitive function. Collectively, they mediated the MIND-cognition association by 13.3% (P-value = 0.024). Adherence to the MIND diet is associated with multiple circulating systemic inflammatory markers involved in neurodegenerative process, which mediate the MIND-cognition association.