When it comes to feeding babies, the old adage "breast is best" certainly holds true, with breastfed babies having less diarrhea and fewer ear infections and incidents of wheezing in early life.
However, the positive effects of infant feeding on lung function may not hold true for children of asthmatic mothers.
“Longer breastfeeding in infancy is associated with improved lung function in later childhood, with minimal effects on airflow in children of non-asthmatic mothers,” wrote Theresa W. Guilbert, M.D., of the University of Wisconsin-Madison and the Arizona Respiratory Center at the University of Arizona in Tucson. “However, longer breastfeeding in children of mother with asthma demonstrates no improved lung growth and significant decrease in airflows later in life.”
The findings were reported in the first issue for November of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.
Dr. Guilbert, working with investigators from the Arizona Respiratory Center, analyzed data from the Children's Respiratory Study in Tucson, Arizona, a prospective population based study of 1,246 infants who were enrolled at birth and monitored through adolescence. Of the original cohort, 679 participants who had performed lung function tests between the ages of 11 and 16, and disclosed complete data on infant-feeding practices were included in the analysis.
Each participant was evaluated for lung function using spirometry. The researchers measured lung volume [forced vital capacity (FVC)] and airflows [forced expiratory volume in one second (FEV1) and FEV1/FVC].
When analyzed as a whole, the group found that FEV1/FVC was lower in breastfed children. However, when the data was analyzed taking maternal allergy and asthma into account, the observed lower airflows associated with longer breastfeeding were only found in those infants with asthmatic or allergic mothers.
“Breast fed children with non-atopic and non-asthmatic mothers had an increase in lung volume and no decrease in their airflows,” wrote Dr. Guilbert. “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.”