Association Between Adherence to the MIND Diet and Cognitive Performance is Affected by Income: The ELSA-Brasil Study.

Background: The relationship between the Mediterranean-DASH Diet Intervention for Neurodegenerative Delay (MIND) diet and cognition has not been widely investigated in low- to middle-income countries. We investigated the relationship between MIND diet and cognition in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) baseline data.

Methods: We included 11,788 participants. MIND diet adherence was based on the intake of 15 components according to a food frequency questionnaire. We analyzed the association between MIND diet adherence and global cognition, memory, and executive function using adjusted linear regression. We examined the interaction between income and MIND diet adherence on cognition and presented income stratified analyses.

Results: MIND diet adherence was not associated with cognition in the whole sample. Income was an effect modifier of MIND adherence on global cognition (P=0.03) and executive function (P<0.001). For participants with high income, greater adherence was associated with better executive function [β=0.015, 95% confidence interval (CI)=0.002; 0.028, P=0.025]; while for participants with low income, greater adherence was associated with lower global cognition (β=-0.020, 95% CI=-0.036; -0.005, P=0.010) and executive function (β=-0.023, 95% CI=-0.039; -0.007, P=0.004). Adherence to the MIND diet was higher among participants with high income (P<0.001).

Conclusion: For high-income participants, greater adherence was associated with better cognitive performance; for low-income participants, greater adherence was associated with lower cognitive performance.