(OR28-05-24) Associations Between Dietary Pattern and Global Cognitive Ability Trajectories Across the Life Course: Longitudinal Analysis of the 1946 British Birth Cohort

Objectives: Diet is a risk factor for later life cognitive decline and dementia, so most studies assess these factors in older populations. Uncovering how diet quality and cognitive function relate over time and stages of life could inform cohort age selection and intervention timing. This study aimed to investigate associations between dietary patterns and global cognitive ability over the life course and to identify when diet may be most predictive of cognitive trajectories.

Methods: This study analyzed data from a subset of the 1946 British Birth Cohort (n = 3,059, 50% male) from the Medical Research Council’s National Survey of Health and Development. We applied group-based trajectory modeling (GBTM) to identify trends in 2020 Healthy Eating Index (HEI) scores across five time points from age 4 to 63 and trends in global cognitive ability measured seven times from age 8 to 69. We compared trends with dual trajectory analysis. Diet was assessed by recalls and food diaries. Cognitive ability was measured with in-house and standardized tests. Multinomial logit models identified baseline risk factors of lower cognitive trajectories and the age when diet was most predictive of lower versus higher cognitive trends.

Results: Three trajectories for diet and five for cognition were modeled by GBTM. The dual analysis of these trajectories showed 47% of participants with the lowest quality diets over time were from the lowest cognitive trajectory (7% were from the highest cognitive trajectory). Conversely, 48% of those with the highest quality diets over time were from the highest cognitive trajectory (8% were from the lowest cognitive trajectory). Multinomial logit models controlling for HEI scores at each age and baseline predictors of trajectory membership found only age 43 dietary patterns significantly predicted less risk of being in the lowest cognitive trajectory. This risk decreased 4% with every one-point increase in age 43 HEI scores (relative risk ratio = 0.96; 95% CI: 0.93, 0.99).

Conclusions: To our knowledge this is the first study to identify links between trends in dietary patterns and global cognitive ability using truly longitudinal data and methods. Our results suggest dietary patterns in midlife, before age 50, may be most predictive of cognitive trends up to age 69. Future research should follow younger cohorts and plan earlier diet interventions.

Funding Sources: None