Washington, Nov 2 : Breastfeeding has its own advantages as nursed babies have less diarrhoea and fewer ear infections and incidents of wheezing in early life. However, a new study has found that babies of asthmatic mothers may suffer breathing problems.

The study, led by Theresa W. Guilbert, M.D., of the University of Wisconsin-Madison and the Arizona Respiratory Centre at the University of Arizona in Tucson studied 1,246 infants who were enrolled at birth and were monitored through adolescence.

“Longer breastfeeding in infancy is associated with improved lung function in later childhood, with minimal effects on airflow in children of non-asthmatic mothers,” Guilbert said.

“However, longer breastfeeding in children of mother with asthma demonstrates no improved lung growth and significant decrease in airflows later in life,” she said.

The analysis of the study included, 679 participants of the original group who had performed lung function tests between the ages of 11 and 16, and disclosed complete data on infant-feeding practices.

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 analysed as a whole, the group found that FEV1/FVC was lower in breastfed children.

 However, when the data was analysed taking maternal allergy and asthma into consideration it was found that 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,” Guilbert said.

“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,” she added.

Guilbert said that the breast milk of non-asthmatic mothers might contain certain factors that promote lung development, citing several possible candidates including cytokines, tumour necrosis factor, epithelial growth factor, and prostaglandin.

In particular, one cytokine, TGF- â1, is related to elastin production, which is important to normal structure and function of the lungs.

The dose of TGF-â1 received by infants via breast milk has been shown to be inversely related to infant wheeze.

“These findings suggest that growth factors in milk have the potential to modify lung development, which might account for some of the protective effect of breastfeeding against wheeze,” Guilbert said.

However, Guilbert cautioned that the clinical implications of the findings were not known.

“Human milk is uniquely suited to the feeding of infants, having been subject to selective pressures for millennia. It is premature to suggest any change in breastfeeding recommendations based on one study, particularly given the multiple well-documented benefits of breastfeeding,” she said.

The study is published in the American Journal of Respiratory and Critical Care Medicine. (ANI)