Aim: We examined the associations between breastfeeding and respiratory allergies and types of asthma in American children.
Methods: This longitudinal study used data from mother-infant pairs who took part in the Infant Feeding Practices Study II in 2005-2007 and the Year 6 Follow-Up Study in 2012. The mothers reported breastfeeding practices on a monthly basis for the first year of life, childhood asthma and allergies at age 6 years, and associated factors. Generalised linear models were used in statistical analyses.
Results: Overall, 1177 mother-infant pairs were included in the sample. A third (32.9%) of the children were exclusively breastfed until the age of 3 months and by the age of 6 years 20.8% had been diagnosed with respiratory allergies and 11.3% with asthma. In the multivariable analyses, exclusive breastfeeding for 3 months was associated with a reduced relative risk of respiratory allergies of 0.77 at the age of 6 years. It also reduced the relative risk of asthma to 0.66, but only if the children did not have a family history of asthma.
Conclusion: This longitudinal study provided evidence that exclusive breastfeeding for the first 3 months may reduce the risk of respiratory allergies and asthma in children 6 years of age, but concerning asthma, statistical significance was reached only in children without a family predisposition to asthma.
Keywords: asthma; exclusive breastfeeding; family predisposition; respiratory allergies.
© 2020 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.