Longer period of exclusive breastfeeding linked with decreased odds of childhood asthma

Reviewed by Emily Henderson, B.Sc.May 25 2022

Pregnant women and new mothers are often presented with information on the benefits of breastfeeding their infants. A new study in Annals of Allergy, Asthma and Immunology, the scientific journal of the American College of Allergy, Asthma and Immunology (ACAAI) shows that a longer period of exclusive breastfeeding was associated with decreased odds of current asthma.

The results of the study indicated that the longer a mother exclusively breastfed, the lower the relative odds of her child having asthma, or asthma-related outcomes. There was a 'dose-response' effect depending on how long the mother breastfed: Babies that were breastfed for 2-4 months had only 64% likelihood of having as many asthma outcomes as those who were breastfed less than 2 months; those breastfed for 5-6 months had 61% likelihood, and those breastfed for more than 6 months had a 52% likelihood."

Keadrea Wilson, MD, lead author of the study and Assistant Professor of Neonatology, University of Tennessee Health Science Center

The study combined three studies to get a large number of subjects – more than 2,000 mother-child pairs. In addition, by combining the studies, the authors achieved a demographic distribution. For example, 38% of the respondents were Black and 6% were Hispanic/Latina.

"A further finding of the study was that duration of breastfeeding mixed with formula/juices/other foods (so not exclusively breastfed) did not provide the same level of protection," says allergist Angela Hogan, MD, vice chair of the ACAAI Asthma Committee. Dr. Hogan was not involved in the research. "Asthma runs in families, and according to the CDC, if a child has a parent with asthma, they are three to six times more likely to develop this condition than someone who does not have a parent with asthma. Anything a parent can do to lower the odds of their child getting asthma is worth considering."

"Our study strengthens current breastfeeding recommendations which reflect recent analysis that show lower risk of asthma with more versus less breastfeeding," said Dr. Wilson.