Exclusive breast-feeding for 6 months, as recommended by the World Health Organization, may protect infants against common infections, according to the results of a prospective study reported online September 28 in the Archives of Disease in Childhood.

“Breastfed infants are considered to be less prone to a variety of infections, including acute otitis media, and gastrointestinal and lower respiratory tract infections,” write Fani Ladomenou, from the University of Crete in Heraklion, Greece, and colleagues.

The goal of the study was to determine the impact of breast-feeding on the frequency and severity of infections in a well-defined population of infants with adequate vaccination coverage and healthcare standards. The investigators recorded type of feeding and all infectious episodes, including acute otitis media (AOM), acute respiratory infection (ARI), gastroenteritis, urinary tract infection, conjunctivitis, and thrush, in a representative sample of 926 infants who were followed up at ages 1, 3, 6, 9, and 12 months.

Compared with partially breast-fed or non−breast-fed infants, those who were exclusively breast-fed for 6 months had fewer infectious episodes. Adjustment for potential confounders did not abolish this protective effect, with odds ratio (OR) of 0.58 for ARI (95% confidence interval [CI], 0.36 – 0.92), 0.37 for AOM (95% CI, 0.13 – 1.05), and 0.14 for thrush (95% CI, 0.02 – 1.02). Although partial breast-feeding was not associated with a reduced risk, prolonged exclusive breast-feeding was associated with fewer infectious episodes (Spearman’s rs = −0.07; P = .019) through age 1 year, as well as with fewer hospitalizations for infection (Spearman’s rs = −0.06; P = .037).

Parental age and education, ethnicity, having siblings, secondhand smoke exposure, season of birth, and other confounding factors also affected the frequency of infections during infancy.

“Findings from this large-scale prospective study in a well-defined infant population with adequate healthcare standards suggest that exclusive breastfeeding contributes to protection against common infections during infancy regarding and lessens the frequency and severity of infectious episodes,” the study authors write. “Partial breastfeeding did not seem to provide this protective effect.”

Limitations of this study include reliance on maternal recall, possible detection bias, nonspecific definition of diarrhea, and possible confounding factors.

“Despite limitations, our results suggest breastfeeding has beneficial effects against common infections in infancy,” the study authors conclude. “This protection seems to be related to the exclusive breastfeeding and its duration. Therefore, mothers should be advised by health professionals that, in addition to all the other benefits, exclusive breastfeeding helps prevent infections in babies and lessens the frequency and severity of infectious episodes.”