Dietary patterns from youth to adulthood and cognitive function in midlife: The cardiovascular risk in Young Finns...

Diet plays an important role in cognitive health, but the long-term association of diet early in life with cognitive function in adulthood has not, to our knowledge, been rigorously studied. The aim of this study was to examine the association of youth, adulthood, and long-term dietary patterns from youth to adulthood with cognitive function in midlife.

This was a population-based cohort study that assessed dietary intake in 1980 (baseline, participants 3-18 y of age), 1986, 2001, 2007, and 2011 and cognitive function in 2011. Six dietary patterns were derived from 48-h food recall or food frequency questionnaires using factor analysis. The dietary patterns were traditional Finnish, high-carbohydrate, vegetables and dairy products, traditional Finnish and high-carbohydrate, red meat, and healthy. Scores of long-term dietary patterns were calculated as the average between youth and adulthood. Cognitive function outcomes assessed included episodic memory and associative learning, short-term working memory and problem solving, reaction and movement time, and visual processing and sustained attention. Standardized z-scores of exposures and outcomes were used for analyses.

Participants (n = 790, mean age 11.2 y) were followed up for 31 y. Multivariable models showed that both youth and long-term vegetable and dairy products and healthy patterns were positively associated with episodic memory and associative learning scores (β = 0.080-0.111, P < 0.05 for all). Both youth and long-term traditional Finnish patterns were negatively associated with spatial working memory and problem solving (β = -0.085 and -0.097, respectively; P < 0.05 for both). Long-term high-carbohydrate and traditional Finnish and high-carbohydrate patterns were inversely associated with visual processing and sustained attention, whereas the vegetable and dairy products pattern was positively associated with this cognitive domain (β = -0.117 to 0.073, P < 0.05 for all). Adulthood high-carbohydrate and traditional Finnish and high-carbohydrate patterns were inversely associated with all cognitive domains except for reaction and movement time (β = -0.072 to -0.161, P < 0.05 for all). Both long-term and adulthood red meat pattern were positively associated with visual processing and sustained attention (β = 0.079 and 0.104, respectively; P < 0.05 for both). These effect sizes correspond to approximately 1.6 to 16.1 y of cognitive aging on these cognitive domains.

Higher adherence to traditional Finnish, high-carbohydrate, and traditional Finnish and high-carbohydrate patterns across the early life course was associated with poorer cognitive function in midlife, whereas higher adherence to healthy and vegetable and dairy product patterns was associated with better cognitive function. The findings, if causative, highlight the importance of maintaining a healthy dietary pattern from early life to adulthood in an attempt to promote cognitive health.