Diet quality and cognitive function in an urban sample: findings from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study.

OBJECTIVE: Poor diet quality contributes to morbidity, including poor brain health outcomes such as cognitive decline and dementia. African Americans and individuals living in poverty may be at greater risk for cognitive decrements from poor diet quality.
DESIGN: Cross-sectional.
SETTING: Baltimore, MD, USA.
SUBJECTS: Participants were 2090 African Americans and Whites (57 % female, mean age=47·9 years) who completed two 24 h dietary recalls. We examined cognitive performance and potential interactions of diet quality with race and poverty status using baseline data from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study. Healthy Eating Index-2010 (HEI-2010) scores were calculated and interpreted using federal guidelines. A neurocognitive test battery was administered to evaluate cognitive function over several domains.
RESULTS: Linear regression analyses showed that lower HEI-2010 scores were associated with poorer verbal learning and memory (P<0·05) after adjustment for covariates. Diet quality within the sample was poor. Significant interactions of HEI-2010 and poverty status (all P<0·05) indicated that higher diet quality was associated with higher performance on tests of attention and cognitive flexibility, visuospatial ability and perceptual speed among those below the poverty line. No significant race interactions emerged. Higher diet quality was associated with better performance on two measures of verbal learning and memory, irrespective of race and poverty status.
CONCLUSIONS: Findings suggest that diet quality and cognitive function are likely related at the population level. Future research is needed to determine whether the association is clinically significant.