(P22-004-24) Long-Term Adherence to a Healthy Diet and Plant-Based Dietary Patterns in Relation to Cognitive Reserve in the 1946 British Birth Cohort: A Cross-Sectional Analysis

Objectives: Cognitive reserve (CR) is the brain’s ability to compensate for brain changes, injury, and disease. CR is represented by crystallized intelligence (acquired knowledge/experience) and influenced by genes and environmental factors like education, occupational complexity, and lifestyle. Yet, the role of diet in CR is not clear. This study aimed to investigate the association between adherence to different dietary patterns across the life course and CR.

Methods: This cross-sectional study used data from the Medical Research Council’s National Survey of Health and Development, 1946 British Birth Cohort. Crystallized intelligence was measured by the National Adult Reading Test (NART) at age 53. We applied the 2020 Healthy Eating Index (HEI) and Plant-Based Diet Indexes (overall PDI, healthful [hPDI], and unhealthful [uPDI]) to diet recalls and food diaries at age 4, 36, 43, and 53. Typical diet over time was measured by energy-adjusted cumulative average index scores. To examine associations between NART and dietary patterns, we ran multiple linear regression models adjusted for factors associated with CR. The proportion of total variance explained (R²) and variability in NART explained by diet was determined by decomposing R² with the Owen value.

Results: Participants with complete data were included (n = 2,514, 48% male). NART was positively associated with HEI, PDI, and hPDI but inversely associated with uPDI in fully adjusted models. Compared to the lowest quintile, those in the highest quintiles for HEI, PDI, and hPDI had significantly higher NART (adjusted mean difference [95% CI]: HEI = 1.53 [0.59, 2.46]; PDI: 0.99 [0.12, 1.85]; hPDI: 0.98 [0.16, 1.79]), while those most adherent to uPDI had lower NART, (-0.95 [-1.85, -0.04]). Among dietary patterns, HEI explained the highest percent of variability in NART (HEI, 2.84%; uPDI, 1.51%; hPDI, 1.05%; PDI, 0.51%).

Conclusions: In this study, higher CR was associated with dietary patterns that aligned with dietary guidelines, had high intakes of overall and healthful plant-based food groups, and had low intakes of less healthy plant-based food groups. Diet helped explain variability in CR and should be included among lifestyle factors in future CR research. Longitudinal analyses are needed to confirm this.

Funding Sources: This study received no external funding. KCC was supported by a PhD stipend from Tufts University.