Relationships between breastfeeding, maternal cigarette smoking during pregnancy, and the cognitive functioning of Akwesasne Mohawk adolescents exposed to environmental pollution

Previous research has suggested that breastfeeding is beneficial for children's health and that maternal cigarette smoking during pregnancy is harmful for children's health. However, there is not a consensus in the existing literature about whether or not these two maternal behaviors impact the cognitive development of children. Furthermore, understanding the role of breastfeeding in children's development is complicated by the fact that breastfeeding transmits toxicants that are stored in the mother's body, including polychlorinated biphenyls (PCBs), to the infant. Existing research suggests that PCBs negatively impact children's cognitive functioning. The current study examined relationships between breastfeeding, maternal cigarette smoking during pregnancy and the cognitive functioning of adolescents from the Mohawk Nation of Akwesasne where there is community concern over industrial pollution of the environment. Cognitive functioning was measured with three cognitive tests, the Woodcock Johnson-Revised, the Test of Learning and Memory, and Raven's Progressive Matrices. The results suggested that the roles of breastfeeding and maternal cigarette smoking during pregnancy in children's cognitive development are intertwined. Breastfeeding had the most pronounced cognitive benefits for adolescents of mothers who smoked cigarettes during pregnancy. Breastfeeding was also especially beneficial for adolescents of mothers who had characteristics that would have made them unlikely to breastfeed. Negative relationships between smoking and cognitive functioning were most prevalent among adolescents who were never breastfed in infancy. Where negative relationships between PCBs and cognitive test scores were evident, they were strongest in the never breastfed group. Part of the reason why existing literature in these areas is inconclusive may be that breastfeeding is only beneficial for the cognitive development of specific groups of children, and smoking cigarettes during pregnancy is particularly harmful for the cognitive development of certain groups of children. The findings suggest that in order to promote positive cognitive development, women should not smoke cigarettes during pregnancy. Recommendations regarding the potential benefits and risks of breastfeeding in this and similar populations need to be carefully weighed in terms of both cognitive and health outcomes.