(Ivanhoe Newswire) – Breastfeeding usually helps babies have better lung function later in childhood, but it may not if their moms have asthma.

A new report from the University of Wisconsin-Madison and the Arizona Respiratory Center at the University of Arizona in Tucson finds longer breastfeeding in children of asthmatic mothers does not improve the child’s lung growth and it significantly decreases their airflow later in life.

Researchers looked at data of infants from birth through adolescence. Participants had lung function tests between the ages of 11 and 16 to measure lung volume [forced vital capacity (FVC)] and airflows ([forced expiratory volume in one second (FEV1) and FEV1/FVC].
 

Results show overall FEV1/FVC was lower in breastfed children. But in infants with asthmatic or allergic mothers the study found lower airflows associated with longer breastfeeding.

“Breast fed children with non-atopic and non-asthmatic mothers had an increase in lung volume and no decrease in their airflows,” writes researcher Theresa W. Guilbert, M.D., University of Wisconsin-Madison and the Arizona Respiratory Center at the University of Arizona in Tucson. “However, children of mothers with asthma who were breastfed four months or more did not demonstrate any improvement in lung volume. Further, they had a significant reduction in airflows, suggesting that the risk for increased asthma in children of asthmatic mothers may be partly due to altered lung growth.”

Guilbert speculates the breast milk of non-asthmatic moms may contain certain factors that promote lung development and protect against wheezing.

SOURCE: American Journal of Respiratory and Critical Care Medicine, 2007;176:843-848