Duration of Breastfeeding Mediates the Association Between Early Socioeconomic Risk and Child Vocabulary at Age 4

• In Event: Poster Session 12
  In Poster Session: PS 12 Topic - Language, Communication

Abstract

Early-life socioeconomic disadvantage is associated with both obesity and worsened cognitive ability beginning in early childhood (Wang & Lim, 2012; Jensen, Berens, & Nelson, 2017). One mechanism that has previously been proposed to link early socioeconomic status and both child obesity and cognition is breastfeeding duration. With regard to child obesity, breast milk contains microbiota and immune factors, which promote healthy metabolic and adiposity profiles. In terms of cognitive benefits, breast milk also contains long‐chain polyunsaturated fatty acids, which are believed to stimulate brain development. Indeed, some evidence suggests that amount of breastfeeding during infancy mediates the association between socioeconomic status and later child obesity (Gibbs & Forste, 2014). However, studies have rarely examined the potential mediating role of breastfeeding in the association between childhood socioeconomic status (SES) and later child BMI in high-income Western countries. Moreover, to our knowledge, no study has investigated breastfeeding duration as a mediator of the relationship between childhood SES and later child vocabulary. The current study aimed to prospectively examine associations between early-life family socioeconomic risk and both BMI and vocabulary at age 4 in a Norwegian cohort, as well as the potential mediating contribution of breastfeeding duration.

The Behavior Outlook Norwegian Developmental Study (BONDS) is an ongoing study following 1,159 families and their children from 6 months of age onward (Nærde, Janson, & Ogden, 2014). Parents reported on various indices of socioeconomic status and duration of breastfeeding in infancy, and measures of child BMI and vocabulary ability were obtained at age 4. Direct and indirect effects were estimated using a path model that adjusted for several demographic and perinatal covariates.

Family socioeconomic risk was found to have a significant negative association with child vocabulary (B(SE)=-0.14(0.07), p<0.05, CI [-0.267, -0.005]) but was unrelated to child BMI. In addition, duration of breastfeeding mediated the association between family socioeconomic risk and child vocabulary, such that greater family socioeconomic risk was significantly associated with a shorter duration of breastfeeding, which in turn significantly predicted poorer child vocabulary (Figure 1). The total indirect effect of family socioeconomic risk on child vocabulary via breastfeeding was significant (B(SE)=-0.04(0.02), p<0.05, CI [-0.066, -0.008]). Collectively, the current findings suggest that a longer duration of breastfeeding is a viable target for preventive interventions aimed at promoting child cognitive outcomes. Breastfeeding promotion efforts reaching families at socioeconomic risk might be particularly beneficial for child cognitive development.

Authors

• Brianna N. Natale, University of Pittsburgh
  Presenting Author

• Daniel S. Shaw, University of Pittsburgh
  Non-Presenting Author

• Harald Janson, The Norwegian Center for Child Behavioral Development (NUBU)
  Non-Presenting Author

• Ane Nærde, The Norwegian Center for Child Behavioral Development
  Non-Presenting Author