Understanding the relationship between breastfeeding and childhood asthma: A systematic review and meta-analysis

Background: Despite breastfeeding being widely recommended, its relationship with asthma continues to be debated. Aims: To carry out a systematic review and meta-analysis of cohort studies to understand if breastfeeding (BF) is inversely associated with physician diagnosed asthma in children. Methods: A comprehensive search was conducted on cohort studies published until June 2018 in any of MEDLINE, EMBASE, Cochrane, CINAHL and ProQuest Nursing and Allied Health Source databases. A manual search of references was conducted for additional resources. Data extraction were restricted to cohort studies or randomized controlled trials that reported physician diagnosed asthma in children aged Results: Out of 46 articles, the meta-analysis of 26 studies indicated that BF compared to no BF was associated with a 21% lower risk of asthma (Pooled effect size, 95% CI=0.79, 0.76-0.83) on asthma and BF. Similarly, children who had been exclusively BF had 28% lower risk (0.72, 0.64-0.80) of asthma and those who had partially breastfed had 17% lower risk (0.83, 0.76-0.90). The heterogeneity among studies that reported any, exclusive and partial BF were 46%, 30% and 45% respectively. Conclusions: The findings suggests that there is 17 to 28% lower risk of asthma in children who are breastfed more, strongly supporting the advocacy for breastfeeding.