Еffects of fortified milk on cognitive abilities in school-aged children: results from a randomized-controlled trial

Abstract

Background: Micronutrients such as vitamins and minerals and long-chain polyunsaturated omega-3 fatty acids (PUFAs) are essential for children’s brain development and cognitive functions. The current study investigated whether milk fortified with micronutrients and PUFA can result in improved cognitive function in mainstream school children. Methods: One-hundred-and-nineteen children (age 8–14, 58 boys) were randomly allocated to a fortified milk group or a regular full milk control group. Participants consumed 0.6L/day of the milk for 5 months. We recorded relevant biochemical, anthropometric, and cognitive measures (working memory and processing speed) at the start of the study and at follow-up after 5 months. Results: The fortified milk significantly increased docosahexaenoic acid (DHA) (change from baseline of 28% [95% CI 17–39%] vs. −6% [95% CI − 13 to 0%] in the control group) and serum 25OH-vitamin D concentrations (41% [95% CI 30–52%] vs. 21% [95% CI 11–30%] in the control group). The fortified milk improved working memory on one of two tests (32% [95% CI 17–47%] vs. 13% [95% CI 6–19%] in the control group). The fortified milk also indirectly increased processing speed on one of two tests; this effect was small and completely mediated by increases in 25OH-vitamin D concentrations. Conclusions: These results suggest that fortifying milk with micronutrients and PUFA could be an effective and practical way to aid children’s cognitive development.