Intake of Vegetables and Fruits Through Young Adulthood Is Associated with Better Cognitive Function in Midlife in the US General Population

Abstract

Background: Vegetables and fruits (VF) may differentially affect cognitive functions, presumably due to their various nutrient contents, but evidence from epidemiologic studies is limited. Objectives The aim of this study was to examine the long-term association between VF intakes, including VF subgroups, in young adulthood and cognitive function in midlife. Methods: A biracial cohort of 3231 men and women aged 18–30 y at baseline in 1985–1986 were followed up for 25 y in the Coronary Artery Risk Development in Young Adults Study. Diet was measured at baseline, and in examination years 7 and 20. Cognitive function was assessed at examination year 25 through the use of 3 tests: the Rey Auditory Verbal Learning Test (RAVLT), the Digit Symbol Substitution Test (DSST), and the Stroop test. The mean differences (MDs) with 95% CIs in cognitive scores across intake categories were estimated through the use of the multivariable-adjusted general linear regression model. Results: Excluding potatoes, intake of whole vegetables was significantly associated with a better cognitive performance after adjustment for potential confounders in all 3 cognitive tests (quintile 5 compared with quintile 1—RAVLT, MD: 0.33; 95% CI: 0.01, 0.64; $P$-trend = 0.08; DSST, MD: 2.84; 95% CI: 0.93, 4.75; $P$-trend < 0.01; Stroop test, MD: −2.87; 95% CI: −4.24, −1.50; $P$-trend < 0.01]. Similarly, intake of fruits, except fruit juices, was significantly related to a better cognitive performance (quintile 5 compared with quintile 1—DSST, MD: 2.41; 95% CI: 0.70, 4.12; $P$trend = 0.03). Conclusions: This study supports the long-term benefits of VF consumption on cognitive performance, except those VF with relatively low fiber content such as potatoes and fruit juices, among the middle-aged US general population.