The effects of 9 months of formulated whole-egg or milk powder food products as meal or snack replacements on executive function in preadolescents: A randomized, placebo-controlled trial

Abstract

Elevated brain choline is associated with better executive functions in preadolescents. Manipulating dietary choline prospectively in preadolescents using egg supplementation could improve executive functions via effects on brain cellular and neurotransmitter functions. We tested the 9-month impacts of egg supplementation on executive functions. It was hypothesized that preadolescents who consumed meal or snack replacement products containing powder made from whole eggs would have the largest improvements in executive functions after 9 months compared to those consuming similar products with either added milk powder or gelatin as a placebo. A randomized, parallel-group, double-blinded, placebo-controlled trial design was used. The executive functions of 122 preadolescents (58 females) aged 9-13 were analyzed before and after the 9-month intervention. The primary outcomes were 3 NIH Toolbox-Cognitive Battery measures of executive function: mental flexibility, working memory, and selective attention and inhibitory control. Participants were randomized to consume food products with either: 1) whole egg powder; 2) milk powder; or 3) gelatin as a placebo, all matched on macronutrient content and used as replacements for commonly consumed foods (i.e., waffles, pancakes, macaroni and cheese, ice cream, and brownies). Hypothesis testing used mixed-effects models that included physical activity and sleep scores as covariates. A statistically significant group × time interaction for selective attention and inhibitory control was found (P=0.049) for the milk group. This interaction resulted from no change for the placebo group and an improvement in selective attention and inhibitory control performance for the milk group by a T-score of 5.8; the effect size (d) was 0.44 SD units. Other comparisons were statistically insignificant. Consumption of foods with added milk powder as a replacement for snacks or meals for 9 months improves selective attention and inhibitory control in preadolescents. Replacement of foods with added whole egg powder does not impact 9-month changes in preadolescent executive functions. This trial was registered at clinicaltrials.gov as NCT03739424.