We recently caught up with Meghan Azad, PhD (MA), and Annika Klopp, MD (AK), to discuss their study on infant feeding and the risk of childhood asthma, published in the Journal of Pediatrics.
PW: What were the goals of your research?
MA: We wanted to determine whether modes of infant feeding in the first 3 months of life were associated with asthma development by age 3 among 3,296 infants from a general population-based cohort. The primary exposure was infant feeding mode at 3 months, classified into 4 categories: breast milk only – all direct breastfeeding, breast milk only – some expressed breast milk, formula and breast milk, and formula only.
PW: What are your most important findings?
AK: Compared with formula feeding, direct breastfeeding appears to be most protective against asthma development, while expressed breast milk appears to confer intermediate protection. There are several possible explanations for this finding: 1) Bioactive components of breast milk may be altered during the expression and storage of breast milk; 2) Expressed breast milk could contain harmful chemicals used in the manufacturing or cleaning of breast pumps and storage containers; 3) There appears to be an important bidirectional exchange of microbes and immune factors between a mother and infant during direct breastfeeding; 4) Suckling at the breast may promote increased lung capacity in infants; 5) Stress and inflammation, which can trigger asthma development, may be reduced by mother-infant bonding that occurs during direct breastfeeding.
What are the implications of your findings?
AK: It is important to promote exclusive direct breastfeeding when it is physically and logistically possible for the mother. Further research is required to establish associations with confirmed asthma later in childhood. Additional studies are needed to determine the underlying mechanisms and maximize the health benefits of indirect breastfeeding when direct breastfeeding is not possible.
Klopp A, Vehling L, Becker A, et al. Modes of infant feeding and the risk of childhood asthma: a prospective birth cohort study. J Pediatr. 2017;190:190-199. Available at https://linkinghub.elsevier.com/retrieve/pii/S0022-3476(17)30946-0.