Impact Of Breastfeeding On Lung Function, Respiratory And Allergic Diseases In School Children

Background: A protective effect of breastfeeding on lung functional growth has been demonstrated in cohorts of children with asthma or risk for asthma; however it is unclear whether this effect is mediated by inflammation or by a direct effect on lung growth. We assessed the impact of breastfeeding on lung function and symptoms at the age of six years in an unselected, healthy birth cohort. Methods: We prospectively studied 377 healthy term infants from the Bern-Basel Infant Lung Development (BILD) cohort from birth up to 6 years. Any breastfeeding was assessed weekly during the 1st year of life. Risk factors (e.g. smoking exposure, parental atopy, and education) were obtained using standardized questionnaires. The primary outcomes were lung function parameters measured at 6 years of age by spirometry (FEV1, FVC, FEV1/FVC, and FEF25-75) and body plethysmography (FRC, TLC and Reff) and FeNO. Secondary outcomes included ever wheeze, wheeze in the past 12 months, asthma, atopy, atopic dermatitis, allergic rhinitis, and allergic sensitization. Results: We found no evidence that breastfeeding could influence any lung function parameters and FeNO. After adjustment for confounders we found no associations of breastfeeding with respiratory symptoms or sensitization. However, a protective effect of breastfeeding on atopic dermatitis was observed only in girls (odds ratio (OR) per each week of breastfeeding 0.96; 95% confidence interval (CI) 0.92-0.99). Conclusion: This study suggests that breastfeeding has no effect on lung function in unselected healthy children with low risk for asthma, our findings do not support our hypothesis that breastfeeding might have a direct impact on lung function at 6 years.