Breastfeeding and Child Cognitive Development - New Evidence From a Large Randomized Trial
Michael S. Kramer, MD; Frances Aboud, PhD; Elena Mironova, MSc; Irina Vanilovich, MD, MSc; Robert W. Platt, PhD; Lidia Matush, MD, MSc; Sergei Igumnov, MD, PhD; Eric Fombonne, MD; Natalia Bogdanovich, MD, MSc; Thierry Ducruet, MSc; Jean-Paul Collet, MD, PhD; Beverley Chalmers, DSc, PhD; Ellen Hodnett, PhD; Sergei Davidovsky, MD, MSc; Oleg Skugarevsky, MD, PhD; Oleg Trofimovich, BSc; Ludmila Kozlova, BSc; Stanley Shapiro, PhD; for the Promotion of Breastfeeding Intervention Trial (PROBIT) Study Group
Arch Gen Psychiatry. 2008;65(5):578-584.
Context The evidence that breastfeeding improves cognitive development is based almost entirely on observational studies and is thus prone to confounding by subtle behavioral differences in the breastfeeding mother's behavior or her interaction with the infant.
Objective To assess whether prolonged and exclusive breastfeeding improves children's cognitive ability at age 6.5 years.
Design Cluster-randomized trial, with enrollment from June 17, 1996, to December 31, 1997, and follow-up from December 21, 2002, to April 27, 2005.
Setting Thirty-one Belarussian maternity hospitals and their affiliated polyclinics.
Participants A total of 17 046 healthy breastfeeding infants were enrolled, of whom 13 889 (81.5%) were followed up at age 6.5 years.
Intervention Breastfeeding promotion intervention modeled on the Baby-Friendly Hospital Initiative by the World Health Organization and UNICEF.
Main Outcome Measures Subtest and IQ scores on the Wechsler Abbreviated Scales of Intelligence, and teacher evaluations of academic performance in reading, writing, mathematics, and other subjects.
Results The experimental intervention led to a large increase in exclusive breastfeeding at age 3 months (43.3% for the experimental group vs 6.4% for the control group; P < .001) and a significantly higher prevalence of any breastfeeding at all ages up to and including 12 months. The experimental group had higher means on all of the Wechsler Abbreviated Scales of Intelligence measures, with cluster-adjusted mean differences (95% confidence intervals) of +7.5 (+0.8 to +14.3) for verbal IQ, +2.9 (–3.3 to +9.1) for performance IQ, and +5.9 (–1.0 to +12.8) for full-scale IQ. Teachers' academic ratings were significantly higher in the experimental group for both reading and writing.
Conclusion These results, based on the largest randomized trial ever conducted in the area of human lactation, provide strong evidence that prolonged and exclusive breastfeeding improves children's cognitive development.
Trial Registration isrctn.org Identifier: ISRCTN37687716
Author Affiliations: Departments of Pediatrics (Drs Kramer, Platt, and Fombonne), Epidemiology and Biostatistics (Drs Kramer, Platt, Collet, and Shapiro and Mr Ducruet), Psychology (Dr Aboud), and Psychiatry (Dr Fombonne), McGill University, Montreal, Quebec, Canada; National Research and Applied Medicine Mother and Child Centre, Minsk, Belarus (Mss Mironova and Kozlova, Drs Vanilovich, Matush, Igumnov, Bogdanovich, Davidovsky, and Skugarevsky, and Mr Trofimovich); and Department of Epidemiology and Community Health, Queen's University, Kingston (Dr Chalmers) and Faculty of Nursing, University of Toronto, Toronto (Dr Hodnett), Ontario, Canada.
fonte: Arch Gen Psychiatry
