The Nutritional and Social Environment-Related Effects of Breastfeeding on Intelligence

The Nutritional and Social Environment-Related Effects of Breastfeeding on Intelligence While various studies document a positive association between duration of breastfeeding and the child’s intelligence, there is an ongoing discussion about the mechanisms behind that association.1,2 The usual approach to distinguish between nutritional and confounding environment-related effects is to control for observable environmental factors in the analysis. Varying availability and measures of control variables make comparisons across studies difficult and lead to different results concerning the partial correlation between duration of breastfeeding and intelligence.1,2 This study provides a new empirical test of the purely nutritional effect of breastfeeding on the child’s intelligence and does not rely on the availability of control variables.