Dietary patterns, cognitive function, and structural neuroimaging measures of brain aging.

Abstract

To examine the cross-sectional associations between dietary patterns and cognitive and neuroimaging indices of brain health concurrently in the same sample of healthy older adults. Dietary patterns were derived from a 130-item food frequency questionnaire for 511 individuals in the Lothian Birth Cohort 1936 (mean age 79.3±0.6years). Composite scores for global cognitive function, visuospatial ability, processing speed, memory, and verbal ability were assessed. Brain volumes and white matter microstructure were assessed in participants (n=358) who also underwent structural magnetic resonance imaging. A Mediterranean-style dietary pattern and a processed dietary pattern were identified using principal component analysis of food frequency questionnaire items. In fully-adjusted linear regression models, adherence to the Mediterranean-style pattern was associated with better verbal ability (β=0.121, P=0.002). Associations with global cognitive function (β=0.094, P=0.043), visuospatial ability (β=0.113, P=0.019), and memory (β=0.105, P=0.029) did not survive correction for multiple comparisons. Associations between the processed pattern and lower cognitive scores were attenuated by around 50% following adjustment for prior (childhood) cognitive ability; only an association with verbal ability remained (β=-0.130, P=0.001). Neither dietary pattern was associated with brain volumes or white matter microstructure. Specific Mediterranean diet features-green leafy vegetables and a low intake of red meat-were associated with better cognitive functioning. These observational findings suggest that adherence to a Mediterranean-style diet is associated with better cognitive functioning, but not better brain structural integrity, in older adults.