Dietary lutein and zeaxanthin are associated with working memory in an older population

Objective:
The purpose of the study was to examine the association between dietary lutein and zeaxanthin (L + Z) intake and immediate word recall (IWR) and delayed word recall (DWR), and to identify the major contributors to dietary L + Z intake in a recent and representative sample of the older US population.

Design:
In this cross-sectional analysis, multivariate path analytic models estimated the association between L + Z consumption and cognitive performance while adjusting for covariates.

Setting:
Observations were drawn from the 2014 Health and Retirement Study, a nationally representative panel study of older US adults, and the 2013 Health Care and Nutrition Study, which assessed dietary intake via FFQ in a subsample of respondents.

Participants:
The analytic sample included 6390 respondents aged ≥50 years.

Results:
L + Z intake was 2·44 ± 2·32 mg/d on average, and L + Z intake differed significantly across quartiles (P < 0·001). For example, average L + Z intake in Q1 was 0·74 ± 0·23 mg/d and in Q4 was 5·46 ± 2·88 mg/d. In covariate adjusted models, older adults in the highest quartiles of L + Z intake had significantly greater IWR and DWR scores than those in the lowest quartile. Leafy vegetables, cruciferous vegetables, dark yellow vegetables, fish and seafood, legumes, eggs and fruit were significant and meaningful predictors of dietary L + Z intake.

Conclusion:
A high consumption of vegetables, fish and seafood, legumes, eggs and fruit is associated with a higher intake of L + Z and greater word recall among older adults.