A longitudinal study of breastmilk feeding duration, EEG power and early academic skills.

ABSTRACT

BACKGROUND: The cognitive benefits of breastfeeding are widely recognized; however, its effects on brain development and later academic skills require further examination. This study aimed to examine the longitudinal relations between breastmilk feeding, neurophysiological changes, and early academic skills. METHODS: In the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort, breastmilk feeding practices were collected every 3 months from 3 weeks to 18 months postpartum. Resting electroencephalography (EEG) was recorded at 18 months and power spectral density was derived. The outcomes were a set of early academic assessments administered at age 4 (n = 810). Structural equation modelling was used to investigate EEG power as a mediator between breastmilk duration and early academic skills. RESULTS: Breastmilk feeding for ≥12 months was associated with better general knowledge, numeracy, and language at age 4 compared to shorter durations of breastmilk feeding (Cohen's d 1.53-17.44). Linear regression showed that breastmilk duration was negatively and positively associated with low- (i.e., delta, theta) and high-frequency power (i.e., gamma), respectively (Cohen's f2 0.03-0.09). After adjusting for demographic and child baseline covariates, a decrease in absolute and relative delta, as well as relative theta was associated with better general knowledge and numeracy (Cohen's f2 0.16-0.25). Relative delta power provided an indirect path between breastmilk duration and early academic skills (x2 18.390, p = 0.010; CFI 0.978; TLI 0.954; RMSEA 0.040). CONCLUSIONS: Extended breastmilk feeding is associated with reduced low-frequency power and better early academic skills, suggesting benefits to brain development. Additional research to confirm this finding is warranted.