Infants exclusively fed colostrum during their first three days of life had a lower likelihood of developing peanut allergy by 12 to 18 months compared with those who received both breast milk and formula, according to a large Australian birth cohort study.
Among 666 mother–infant pairs, partial colostrum feeding—defined as giving both breast milk and formula in the first 72 hours—was associated with a higher likelihood of immunoglobulin E (IgE)-mediated peanut allergy and multiple food allergies. Peanut allergy occurred in 2.7% of partially colostrum-fed infants compared with 0.3% of those exclusively fed colostrum. Fewer colostrum feeds during the first three days of life were linked to higher odds of peanut allergy, while more frequent feeds corresponded with lower risk.
Timing of peanut introduction also influenced outcomes. Among partially colostrum-fed infants, those introduced to peanut later than seven months of age were more likely to develop peanut allergy compared with those introduced earlier. In contrast, infants exclusively fed colostrum had a low risk of peanut allergy regardless of when peanut was introduced.
Across the cohort, 46% of infants were partially colostrum-fed. Overall, 8.7% were sensitized to at least one food allergen, and 4% had IgE-mediated food allergy, with egg being the most common, followed by peanut, milk, and cashew. Sensitization rates did not differ significantly between feeding groups, suggesting that the observed differences reflected clinical allergy outcomes rather than sensitization.
Infants who received formula supplementation also had shorter breastfeeding durations and higher antibiotic exposure within the first year of life. Nearly half of formula supplementation was medically indicated, commonly for neonatal hypoglycemia, jaundice, or weight loss, while the remainder was due to nonmedical reasons such as maternal request or unsettled infant behavior.
“These findings on the benefits of colostrum contrast with systematic reviews and meta-analyses indicating that breastfeeding's role in food allergy prevention is inconclusive,” said Maheshwar Bhasin of the Telethon Kids Institute at the University of Western Australia, and colleagues.
Researchers used Firth-penalized logistic regression to account for rare outcomes and adjusted for factors including parental allergy, socioeconomic status, mode of birth, and season of birth. Food allergy outcomes were determined at 12 to 18 months through skin-prick testing and parent-reported immediate allergic reactions.
Limitations included the lack of oral food challenges to confirm IgE-mediated food allergy, the observational study design, and the small number of peanut allergy cases, which limited statistical precision. The follow-up period also ended at 18 months, precluding assessment of later-onset food allergies.
A.J.L. received an investigator-initiated grant from GlaxoSmithKline (GSK) and Sanofi Regeneron for unrelated research, and an investigational product (EpiCeram) free of charge from Primus Pharmaceuticals for use in unrelated research. All other authors declared no competing interests related to the writing of the manuscript.
Source: Allergy
