Relations to Cognitive Change with Age of Micronutrients Found in Green Leafy Vegetables

Abstract

Consumption of green leafy vegetables has been reported to reduce cognitive decline in older adults. We investigated the relations to cognitive decline of various micronutrients for which green leafy vegetables are a rich dietary source, including phylloquinone (vitamin K), folate and carotenoids (lutein, lycopene, beta‐cryptoxanthin, alph carotene, beta carotene), in a cohort study of 954 participants of the Memory and Aging Project, mean age 81 years, 75% female. Diet was assessed by a 144‐item semi‐quantitative food frequency questionnaire. Energy‐adjusted nutrients were modeled in quintiles. Cognition was assessed annually by a battery of 19 tests. Nutrient intakes were related to change in cognitive function over a mean 4.5 years using linear‐mixed models adjusted for age, sex, education, and participation in cognitive activities. Higher green leafy vegetable consumption was associated with slower cognitive decline (β=0.033, SE=0.010, p=0.001). In analyses of micronutrients, we observed slower rates of cognitive decline for food folate (Q5 vs Q1 β=0.044, p=0.004), phylloquinone (Q5 vs Q1 β=0.040, p=0.001), lutein (Q5 vs Q1 β=0.039, p=0.001), and total beta carotene (Q5 vs Q1 β=0.029, p=0.01). No associations were observed for lycopene, alpha carotene, or beta‐cryptoxanthin. Cognitive decline in older adults may be slowed through the consumption of green leafy vegetables rich in folate, phylloquinone, lutein and beta carotene.Supported by grants R01 AG031553 and R01 AG17917