Another study (J Pediatr 2014; 164: 487-93, editorial pg 440-42) echoes yesterday’s study.
Design: The authors used a nationally representative sample in a longitudinal survey of 7500 children. In addition to breastfeeding practices, the authors explored parenting behaviors including putting an infant to bed with a bottle and frequency of reading.
Results: “there is a positive relationship between predominant breastfeeding for 3 months or more and child reading skills, but this link is the result of cognitively supportive parenting behaviors and greater levels of education among women who predominantly breastfed. We found little-to-no relationship between infant feeding practices and the cognitive development of children with less-educated mothers. Instead, reading to a child every day and being sensitive to a child’s development were significant predictors of math and reading readiness outcomes.”
Take-home message: the editorial states that parents should not be concerned that being unable to breastfeed will be detrimental to a child’s cognitive function. But, “encouragement of breastfeeding for other reasons, including health benefits to the infant and enhancement of mother-infant attachment”…merit recommendation along with good parenting practices (eg. reading to infants).
A recent study further explored breastmilk’s effect on infant cognitive and motor development in the French EDEN Mother-Child Cohort Study (J Pediatr 2013; 163: 36-42).
The authors acknowledge that previous studies have shown that breastfed children have higher scores at tests on cognitive abilities; “however, some authors suggested that these results were due to the difference between the socio-demographic and occupational characteristics of mothers who breastfed and those who did not.” Though, a large randomized trial (Arch Gen Psychiatry 2008; 65: 578-84) showed convincing data that a longer duration of exclusive-breastfeeding duration improved children’s cognitive development.
So why did the authors bother with this study? The authors note that few studies have been performed in France where breastfeeding is less common than other European countries and their object of showing a dose-response relationship would further the arguments for causality.
Design: 1387 two-year-olds and 1199 three-year-old children were assessed from the EDEN cohort (2002 pregnancies) which prospectively collected data at birth, 4 months, 8 months, 1 year, and 2 years.
- After adjusting for many confounding factors, infants who had breastfed scored 3.7 points higher on the Communicative Development Inventory (CDI) than infants who had never breastfed.
- Longer breastfeeding duration was associated with better cognitive and motor development in 2- and 3-year-old children. Each additional month of breastfeeding was associated with an increase of 0.75 CDI points and 1.00 in the Ages and Stages Questionnaire (ASQ).
Take-home message: Most studies, including the present, have shown benefits of breastfeeding on infant development. In addition, there is likely a dose-response relationship.
Related blog posts:
A large cohort study from the United Kingdom with 11,101 term infants and 778 preterm infants shows improved cognitive development when infants are breastfed. J Pediatr 2012; 160: 25-32. There have been a number of previous studies as well that have shown that breastfed children have an IQ that is ~5 points higher than nonbreastfed children; however, when adjustment for confounders, especially maternal education, this effect is weaker. Since this is an observation study (randomized blinded study would be impossible), it is difficult to control for all variables. Nevertheless, prolonged breastfeeding, more than 2 months in preterm and more than 4 months in term infants, is associated with higher cognitive development.
- Am J Clin Nutr 199; 70: 525-35.
- BMJ 2006; 333: 945.
- Arch Gen Psychiatry 2008; 65: 578-84.
- Paediatr Perinat Epidemiol 2003; 17: 81-90.
- J Pediatr 2009; 155: 421. Breastfeeding may have possible protective effect from developing inflammatory bowel disease. Review of multiple studies.
- J Pediatr 2002; 141: 764. Breastfeeding may protect against obesity.
- BMJ 2007; 335: 815-20. Longer time of breastfeeding does not reduce allergy/asthma. n=17,046 pairs of mother-infant (13,889 followed up at age 6.5yrs)