Breastfeeding is associated with improved lung function at school age, particularly in children with asthmatic mothers, according to a new studying from researchers in Switzerland and the United Kingdom. The findings appear in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.
Analyzing data from a nested sample of 1,458 children born between 1993 and 1997, the researchers assessed duration of breastfeeding, other exposures, and respiratory symptoms by repeated questionnaires. Post-bronchodilator FVC, FEV1, peak expiratory flow rates (PEF), forced expiratory flow at 50% (FEF50), and skinprick tests were measured at age 12.
In the entire sample of children, FEF50 was significantly higher in breastfed children compared with those who were not breastfed, increasing by 0.130 L/sec (p = 0.048) in those breastfed for 4 to 6 months and 0.164 L/sec (p = 0.041) in those breastfed for more than 6 months. These effects were larger among children of mothers with asthma, with increases of 0.375 L/sec (p = 0.015) in those breastfed for 4 to 6 months and 0.468 L/sec (p = 0.009) in those breastfed for more than 6 months. Significant improvements in FVC and FEV1 with breastfeeding were seen only in the children of asthmatic mothers. Adjustments for respiratory infections in infancy and asthma and atopy in childhood did not change the results of these analyses.
The study had several limitations, including a modest response rate of the original cohort for laboratory examinations and the use of self-report for determining duration of breastfeeding, maternal asthma, and infections during infancy.
"We observed modest improvements in lung function in breastfed children in our cohort, including the children of mothers with asthma. Furthermore, our data suggest that rather than acting by reducing respiratory infections, asthma or allergy, breastfeeding might have a direct effect on lung growth," said Claudia E. Kuehni, MD, MSc, professor at the Institute of Social and Preventative Medicine at the University of Bern. "This study supports a strong recommendation for breastfeeding in all children, including those with asthmatic mothers."
Source: American Thoracic Society