Chalada P, Arbes S, Dunson D, Zeldin DC. J Allergy Clin Immunol. 2003;111:328–336
Purpose of the Study.
To determine whether breastfeeding has an association with the development of recurrent wheeze, asthma, or both among children up to 72 months of age and whether the duration or exclusivity of breastfeeding has an effect on this association.
Children (n = 8261), 2 to 71 months of age, were sampled from the Third National Health and Nutrition Examination Survey, a nationally representative, cross-sectional survey conducted between 1988 and 1994 and designed to provide health estimates for the US population.
Data used in this study were obtained with the Third National Health and Nutrition Examination Survey Household Youth Questionnaire. Data were tested for significant associations between breastfeeding and physician-diagnosed asthma or recurrent wheeze (≥3 episodes of wheeze within the previous 12 months), with and without adjustments for confounding variables.
Of the original cohort, 7766 children had available data on breastfeeding duration, recurrent wheeze, and all covariates. Prevalences of physician-diagnosed asthma and recurrent wheeze were 5.9% and 7.6%, respectively. Approximately one-half of the children were reported to have ever been breastfed. Unadjusted model results showed that children who had ever been breastfed were less likely to be diagnosed with asthma or to have recurrent wheeze, compared with those who had never been breastfed, whereas those were breastfed for a longer time (≥4 months) had the lowest odds of asthma or wheeze. After adjustment for potential confounders, these results were not statistically significant. However, the investigators showed that children who had ever been breastfed had a decreased likelihood of recurrent wheeze or asthma before the age of 24 months, compared with children who had never been breastfed. Children with environmental tobacco smoke (ETS) exposure (37.9%) had a higher prevalence of asthma than did those from smoke-free homes. Children between the ages of 2 and 71 months with ETS exposure who had ever been breastfed were less likely to develop recurrent wheeze or asthma than were children who had not been breastfed, especially if the duration was ≥4 months.
Breastfeeding might delay the onset of or actively protect children <24 months of age against asthma and recurrent wheeze and might reduce the prevalence of asthma and wheeze among children exposed to ETS.
Recurrent wheeze and asthma are leading reasons for hospitalization and emergency department visits among children in the United States. Appropriate asthma diagnosis and treatment is especially difficult among children <24 months of age. In addition, ETS exposure is prevalent among young asthmatic patients and can compromise clinical outcomes. This study indicates that breastfeeding may have important effects on asthma and may provide protection from the ill effects of ETS. Broad-based public health strategies are needed to better educate individuals about preventive measures, such as breastfeeding and reduction of ETS exposure.