Breastfeeding and Asthma Among Brazilian Children

Abstract

We examined the association of breastfeeding and the presence of chronic respiratory symptoms among 5,182 Brazilian schoolchildren 7-14 years of age who were participants in the International Study on Asthma and Allergies in Childhood (ISAAC). The prevalence of medically diagnosed asthma and current wheeze were respectively 4.6% (95% confidence interval [CI] 4.0%-5.2%) and 11.9% (95% CI 11.0%-12.8%). Ninety percent of the mothers in our study population had breastfed their child. After adjusting for potential confounding factors, we found that children who had not been breastfed were more likely to have a medical diagnosis of asthma (odds ration [OR] = 1 .51, 95% CI 1.00-2.51), experience current wheeze (OR = 1.29, 95% CI 0.96-1.74), and wheeze after exercise (OR = 1.51, 95% CI 1.01-2.27) than children who had been breastfed for more than 6 months. This effect was only present among children with no family history of asthma (OR = 1.54, 95% CI 0.90-2.42 for medical diagnosis of asthma; OR = 1.27, 95% CI 0.93-1.75 for current wheezing; and OR = 1.74, 95% CI 1.12-2.6 for wheeze after exercise). We conclude that the low prevalence of asthma and wheeze observed in our population may be partly related to the high level of breastfeeding.

Breast-feeding and atopic disease: A cohort study from childhood to middle age

“…Our study for the first time provides an explanation why some studies of breast-feeding have observed a protective effect against asthma and atopy, 13,[22][23][24][25][26][27][28] whereas other studies showed an increased risk. [7][8][9][10][11][12] We are the first to analyze data from early childhood well into middle age.…”

“…Several studies 13,[22][23][24][25][26][27][28] and 2 recent meta-analyses 1,2 have reported a protective effect of breast-feeding in the first few years of life. We found exclusive breastfeeding did have a protective effect against risk of current asthma, infantile eczema, and food allergies at 7 years of age.…”

Breastfeeding and asthma and allergies: a systematic review and meta‐analysis

“…Five studies investigated the association between breastfeeding and allergic disease stratified by familial atopy (Fig. S5).…”

Associations of Doctor-Diagnosed Asthma with Immigration Status, Age at Immigration, and Length of Residence in the United States in a Sample of Mexican American School Children in Chicago

“…Some studies (41)(42)(43)(44)(45) have reported a protective effect for breastfeeding against the development of asthma or atopy. But variations in breastfeeding proportions among Mexican American children noted by this study as well as previous research (9) did not explain the negative effects of migration observed in the current study or in our previous investigation using national data (9).…”