Abstract P400: Dietary Pattern is Associated with Better Cognitive Function: The CARDIA Study

Abstract

Primary prevention of cognitive function decline is important for a middle-aged population, but further evidence about the influence of dietary pattern is needed. An A Priori Diet Quality Score (diet score) and cognitive function were studied in the community-based Coronary Artery Risk Development in Young Adults (CARDIA) study of black and white men and women aged 18-30 in 1985-86 (year 0, Y0). We hypothesized that a higher diet score, measured at Y0 and Y20, predicts better cognitive function measured at Y25. The diet scores incorporated 46 foods groups (each in servings/day categorized into quintiles), with higher scores indicating higher quality diets. The score was the sum of quintile ranks of foods rated healthy, 0 for foods rated neutral, and reversed quintile ranks of foods rated less healthy. Cognitive tests at Y25 measured verbal memory (Rey Auditory-Verbal Learning Test (RAVLT)), psychomotor speed (Digit Symbol Substitution Test (DSST)) and executive function (Stroop Test). Higher cognitive function is reflected by higher RAVLT and DSST scores and lower Stroop Test scores. For each additional 10 units of diet score at Y20, the RAVLT was 0.23 words recalled higher, the DSST was 0.87 digits higher, and the Stroop Test score was 0.69 lower. Diet score measured at Y0 was less strongly but still significantly associated with cognitive scores. In exploratory analysis, we found that education modified the relation between diet pattern and cognitive function measures, e.g. diet and DSST at Y20 were associated in less educated subjects, but not in higher educated subjects (P for interaction =0.02). In conclusion, higher diet score was associated with better cognitive function 5 years later in apparently healthy middle-aged adults. However, diet pattern was not related to some measures of cognitive function in better educated subjects, conceivably because of compensatory behaviors in better educated people that would maintain higher cognitive function scores, despite lower quality diet.