Nutrients or nursing? Understanding how breast milk feeding affects child cognition.

PURPOSE

To explore the associations between type of milk feeding (the "nutrients") and mode of breast milk feeding (the "nursing") with child cognition.

METHODS

Healthy children from the GUSTO (Growing Up in Singapore Toward healthy Outcomes) cohort participated in repeated neurodevelopmental assessments between 6 and 54 months. For "nutrients", we compared children exclusively bottle-fed according to type of milk received: formula only (n = 296) vs some/all breast milk (n = 73). For "nursing", we included only children who were fully fed breast milk, comparing those fed directly at the breast (n = 59) vs those fed partially/completely by bottle (n = 63).

RESULTS

Compared to infants fed formula only, those who were bottle-fed breast milk demonstrated significantly better cognitive performance on both the Bayley Scales of Infant and Toddler Development (Third Edition) at 2 years [adjusted mean difference (95% CI) 1.36 (0.32, 2.40)], and on the Kaufman Brief Intelligence Test (Second Edition) at 4.5 years [7.59 (1.20, 13.99)]. Children bottle-fed breast milk also demonstrated better gross motor skills at 2 years than those fed formula [1.60 (0.09, 3.10)]. Among infants fully fed breast milk, those fed directly at the breast scored higher on several memory tasks compared to children bottle-fed breast milk, including the deferred imitation task at 6 months [0.67 (0.02, 1.32)] and relational binding tasks at 6 [0.41 (0.07, 0.74)], 41 [0.67 (0.04, 1.29)] and 54 [0.12 (0.01, 0.22)] months.

CONCLUSIONS

Our findings suggest that nutrients in breast milk may improve general child cognition, while nursing infants directly at the breast may influence memory.