Associations of Breastfeeding Duration and Cognitive Development from Childhood to Middle Adolescence.

Aim: To assess the dose-response association between the duration of any breastfeeding and cognitive skills in children from 5 to 15 years of age. Methods: The data from the longitudinal cohort study Growing up in Australia: The Longitudinal Study of Australian Children (children born in 1999-2000 and 2003-2004) were accessed. Language skills were assessed via Peabody Picture Vocabulary Test at 5, 7 and 9 years of age (N = 8643), and non-verbal intelligence was assessed via Matrix Reasoning subtest from Wechsler Intelligence Scale at 7, 9 and 11 years of age (N = 8560) and executive functions were examined via Cogstate Cognitive Testing battery in 15 years old (N = 6213). Breastfeeding was assessed via maternal questionnaires, partly prospective. Results: A longer duration of breastfeeding was significantly associated with greater language skills from 5 to 9 (0.05 [95% CI, 0.03-0.08], p < 0.0001) and greater non-verbal intelligence from 7 to 11 years of age (0.02 [95% CI, 0.01-0.04], p < 0.001). No significant relation was found between the breastfeeding duration and executive functions in 15 years old. Conclusion: These results support a dose-response relationship between breastfeeding duration and language skills and non-verbal intelligence during childhood and early adolescence.