Breastfeeding newborns and infants can lessen the likelihood that they will develop Crohn’s disease (CD) and ulcerative colitis (UC) later in life, new review study shows.
And the longer a child is breastfed, the better, its researchers say.
The study, “Systematic review with meta-analysis: breastfeeding and the risk of Crohn’s disease and ulcerative colitis,” appeared in the journal Alimentary Pharmacology and Therapeutics.
Causes of inflammatory bowel disease (IBD), which include both CD and UC, remain poorly understood. But the composition of the gut’s microbiota (the population of microorganisms there) and factors that influence it are increasingly seen as important players in the development and progression of IBD. Research has shown that the gut’s microbiota is particularly susceptible to influences in early infancy.
Breastfeeding may alter the development of immune-mediated diseases in many ways, including protecting babies against infections in infancy. Breastfeeding modulates the composition of the gut’s microbiota, and previous research has suggested it can modestly reduce the risk of IBD. However, these results were derived from studies with a number of limitations, such as not accounting for duration of breastfeeding and not assessing risk by geography or ethnicity.
Researchers at Massachusetts General Hospital and Harvard Medical School aimed to conduct a more detailed analysis of the relationship between breastfeeding and the risk of CD and UC. The analysis was centered on 35 studies from 1961 to 2016, and gathered from two popular online sources. A total of 7,536 patients with CD, 7,353 with UC, and 330,222 controls were evaluated.
Breastfeeding habits were mostly obtained in the studies from questionnaires. Patients in the study ranged from children to adults, and studies came from Europe, North America, and Asia.
Results showed that even minimal breastfeeding was associated with a lower risk of CD and UC later in life. The longer an infant was breastfed — especially 12 months or more — the greater the decrease that was seen in disease risk, a decline observed by comparing disease in people reporting long-duration feeding to those breastfed for three or six months.
The study demonstrated that breastfeeding for 12 months or longer led to an even stronger likelihood of preventing UC than did an appendectomy (removal of the appendix).
“We demonstrate a strong inverse association between breastfeeding in infancy and development of paediatric and adult-onset IBD,” the researchers wrote. “We also demonstrate a dose-response effect with the greatest benefit being observed with breastfeeding for at least 12 months. Our findings highlight the significant additional benefit of breastfeeding beyond providing nutrition and protection against infections for the newborn.”
The benefit was observed across all ethnicity groups, but the magnitude of protection in CD patients was greater among Asians compared to Caucasians. The authors primarily attribute this result to a higher prevalence of childhood infections in Asia, which can cause IBD. Therefore, strongest reduction of infections by breastfeeding in this population may lead to a greater decrease in IBD.
Anti-bacterial components and antibodies present in breastmilk may be the reason this protection seems to exist, the team suggests. Their effect may be direct or indirect, by boosting the infant’s innate immunity.
Among the study’s limitations, the authors cite the heterogeneity between the included studies, the lack of studies including individuals of diverse ethnic backgrounds, and the fact that breastfeeding was only inquired after an IBD diagnosis. The scientists were also not able to evaluate the influence of timing of weaning on the risk of IBD.
Overall, “in conjunction with the robust evidence base behind panoply of benefits of breastfeeding, these data support the recommendation of breastfeeding in infancy for babies to reduce risk of development of IBD,” the study concluded.