: JAMA 2002 May 8;287(18):2365-71
The association between duration of breastfeeding and adult intelligence.
Mortensen EL, Michaelsen KF, Sanders SA, Reinisch JM.
Institute of Preventive Medicine, Kommunehospitalet, DK-1399 Copenhagen K, Denmark. [email protected]
CONTEXT: A number of studies suggest a positive association between breastfeeding and cognitive development in early and middle childhood. However, the only previous study that investigated the relationship between breastfeeding and intelligence in adults had several methodological shortcomings. OBJECTIVE: To determine the association between duration of infant breastfeeding and intelligence in young adulthood. DESIGN, SETTING, AND PARTICIPANTS: Prospective longitudinal birth cohort study conducted in a sample of 973 men and women and a sample of 2280 men, all of whom were born in Copenhagen, Denmark, between October 1959 and December 1961. The samples were divided into 5 categories based on duration of breastfeeding, as assessed by physician interview with mothers at a 1-year examination. MAIN OUTCOME MEASURES: Intelligence, assessed using the Wechsler Adult Intelligence Scale (WAIS) at a mean age of 27.2 years in the mixed-sex sample and the Borge Priens Prove (BPP) test at a mean age of 18.7 years in the all-male sample. Thirteen potential confounders were included as covariates: parental social status and education; single mother status; mother's height, age, and weight gain during pregn