Authors recruited newborns from 4 hospitals in Okinawa, Japan. Participants were randomly allocated to ingest =10 mL of cow's milk formula daily (ingestion group) or avoid cow's milk formula (avoidance group) between 1 and 2 months of age. The avoidance group supplemented breastfeeding with soy formula as needed.
Oral Food Challenge
An oral food challenge was performed at 6 months of age to assess cow's milk allergy development. Continuous breastfeeding was recommended for both groups until 6 months of age.
Five-hundred and four infants were randomized. Twelve participants declined to receive the intervention, and the study sample comprised 491 participants (ingestion group: 242; avoidance group: 249) for the modified intention-to-treat analysis.
Safe and Practical
The number of cow's milk allergy cases was 2 (0.8 percent) of 242 in the ingestion group and 17 (6.8 percent) of 249 in the avoidance group (risk ratio: 0.12; 95 percent confidence interval: 0.01–0.50; P<.001). The risk difference was 6.0 percent (95 percent confidence interval: 2.7–9.3). Approximately 70 percent of participants continued to breastfeed at 6 months of age in both groups.
This study demonstrates that daily ingestion of =10 mL of cow's milk formula between 1 and 2 months of age prevents the development of cow's milk allergy and does not compete with breastfeeding. This multicenter randomized controlled trial in infants from the general population demonstrates a safe and practical strategy for preventing cow's milk allergy.
Source: Sakihara T, et al. "Randomized trial of early infant formula introduction to prevent cow's milk allergy." The Journal of Allergy and Clinical Immunology 2 September 2020.

