Risks for food allergy increase with mixed diets in first 3 days of infancy
Key takeaways:
- 46% of infants did not exclusively receive colostrum during their first 3 days of life.
- Infants with mixed diets who were introduced to allergens after age 7 months had higher risks for food allergy.
SAN DIEGO — Infants who did not exclusively feed on colostrum during their first 3 days of life were more likely to develop egg or peanut allergy, according to an abstract presented here.
Risks increased further when allergens were introduced into diets later, Maheshwar Bhasin, MSc, DNHE, CPM, PhD scholar, University of Western Australia, said at the 2025 American Academy of Allergy, Asthma & Immunology/World Allergy Organization Joint Congress.
A third of newborns around the world receive formula within their first 3 days, the researchers noted, adding that these unphysiologically high amounts of supplement reduce how much colostrum that these infants receive.
“We were impressed by the high frequency of formula feeding in the first 3 days of life worldwide,” Bhasin told Healio. “During this critical transition period to extrauterine life, nature has designed a special fluid for the newborn, colostrum.”
However, he continued, little is known about the long-term effects when colostrum feeding is interrupted.
“Our center has collected data in a preclinical model and found that colostrum is critical in shaping the microbiota as well as in preventing food allergies,” Bhasin said. “This has led us to translate our findings into the ORIGINS Australian birth cohort.”
Rich in bioactive compounds, the researchers said, colostrum may be vital in the development of healthy immune systems. Including formula into the diets during those first 3 days may have a significant impact on risks for allergies beyond cow’s milk, the researchers hypothesized.
The study included 666 mother-infant dyads from the ORIGINS cohort in Australia, and 46% of the infants were not exclusively fed colostrum through age 3 days.
“Mothers were predominantly Caucasian ethnicity, highly educated with an average age of 32,” Bhasin said. “Infants were all term-born, healthy, and nearly half of them were born by caesarean section.”
The researchers defined food allergy at age 1 year as a positive skin prick test and an immediate reaction to the food as reported by the mother.
In adjusted models, the infants who were not exclusively fed colostrum were 3.41 times (95% CI, 1.1-10.54) more likely to develop an egg allergy and 5.66 times (95% CI, 1.08-29.82) more likely to develop a peanut allergy, both by age 12 to 18 months, than the infants who were exclusively fed colostrum.
Adjusted odds ratios for developing an allergy among infants who were not exclusively fed colostrum and who also were not introduced to allergens until after age 7 months included 9.5 (95% CI, 2.29-39.38) for egg and 7.57 (95% CI, 1.35-42.46) for peanut, compared with infants who were exclusively fed colostrum and who also were introduced to allergens before age 7 months.
Also, Bhasin said, infants who had nine or more colostrum feedings within the first 24 hours of their lives did not develop any peanut allergies, even if they had formula during the first 24 hours as well.
Based on these findings, the researchers concluded that risks for food allergies increased among infants who were not exclusively fed colostrum, with delays in introducing allergens into their diets increasing these risks, indicating that colostrum feeding may prevent food allergy.
These findings also have direct implications for public health and for the one in three newborns who receive nonexclusive colostrum feedings, Bhasin said, with long-term impacts on their health.
“If newborns require formula milk supplementation, a simple way to promote peanut allergy prevention would be to increase colostrum feedings to nine or more on the first day of life,” Bhasin said.
Also, Bhasin said, these findings suggest that when newborns receive partial colostrum feedings, it becomes more imperative to introduce peanut into their diet before age 7 months.
Further, the timing of peanut introduction did not affect the low risk for peanut allergy among babies who exclusively consumed colostrum.
“These findings will reduce stress and anxiety for some parents about when to introduce the allergen,” Bhasin said.
Ideally, he continued, a randomized controlled trial would be needed to validate these findings indicating that colostrum feeding is beneficial in preventing peanut allergy.
“As this may be difficult to set up due to ethical concerns, we aim to replicate our findings in other cohorts worldwide,” Bhasin said. “We will also conduct basic research to identify the mechanisms of colostrum protection. This research may lead to the discovery of new therapeutics for infants at high risk of allergy.”
Reference:
- Partial colostrum feeding association with higher risk of childhood food allergies. https://www.aaaai.org/about/news/news/2025/colostrum. Published Feb. 10, 2025. Accessed Feb. 10, 2025.
For more information:
Maheshwar Bhasin, MSc, DNHE, CPM, can be reached at maheshwar.bhasin@thekids.org.au.