Dietary patterns during adulthood and cognitive performance in midlife: The CARDIA study

Objective: To investigate whether dietary patterns (Mediterranean diet (MedDiet), Dietary Approaches to Stop Hypertension (DASH) and A Priori Diet Quality Score (APDQS)) during adulthood are associated with midlife cognitive performance. Methods: We studied 2,621 CARDIA participants: 45% black, 57% female, and age 25±3.5 years at baseline (year 0). Mean diet scores were calculated from diet history at baseline, year 7 and year 20 (mean age 25, 32 and 45 years respectively). Cognitive function was assessed at year 25 and 30 (mean age 50 and 55 years respectively). Linear models were used to examine association between tertiles of diet score and change in composite cognitive function and cognitive z-scores (verbal memory (RAVLT), processing speed (Digit Symbol Substitution Test (DSST)) and executive function (Stroop Interference)), and the Montreal Cognitive Assessment (MoCA) at year 30. Results: DASH was not associated with change in cognitive performance. Higher MedDiet and APDQS scores were associated with less decline in cognitive function (MedDiet: low=-0.04, mid=0.03, high=0.03, P=0.03; APDQS: low=-0.04, mid=-0.00, high=0.06, P<0.01) and Stroop interference (MedDiet: low=0.09, mid=-0.06, high=-0.03; APDQS: low=0.10, mid=0.01, high=-0.09, both P<0.01). Odds ratios (95% confidence interval) for poor global cognitive function (≥1 SD below mean MoCA) comparing extreme tertiles of diet scores were: 0.54 (0.39-0.74) for MedDiet, 0.48 (0.33-0.69) for APDQS and 0.89 (0.68-1.17) for DASH. Conclusion: Greater adherence to MedDiet and APDQS dietary patterns during adulthood was associated with better midlife cognitive performance. Additional studies are needed to define the combination of foods and nutrients for optimal brain health across the life-course.