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5MinuteConsult Journal Club

Cow’s Milk in Infancy Prevents Milk Allergy


J Allergy Clin Immunol .2020 Sep 2;S0091-6749(20)31225-2. doi: 10.1016/j.jaci.2020.08.021 

Study Summary

This trial of 504 breastfeeding infants in Okinawa, Japan who were screened for cow’s milk allergy at one month of age; if negative, they then randomized to 10 ml of Cows Milk Formula every day between the ages of 1-2 months of age or avoidance of cow’s milk formula. At 6 months of age, the development of Cows Milk Allergy was assessed as well as the influence of the cow’s milk supplementation on continued breast feeding. Should supplementation be needed, parents were encouraged to use only soy based formulae. 


At 6 months, there were 2 cases (0.8%) of cow’s milk allergy among the 242 who received the cow’s milk and 17 cases (6.8%) among the 249 who avoided cow’s milk (risk ratio = 0.12; 95% CI = 0.01-0.50; P < .001). This led to a number needed to treat of 17 to prevent one additional case of cow’s milk allergy. ~70% of both groups were still being breast-fed at 6 months of age. 


In children in Japan, the addition of daily 10 ml of cow’s milk formula between 1-2 months of age lowers the risk of cows milk allergy at 6 months of age. 


This could be practice changing… if replicated in other populations. Japan is largely a homogeneous population, with genetic risks of milk allergy that may be different from others. But like the recommendations on introduction of nuts, eggs and seafood in the first year of life, adding a cow’s milk formula might soon become a standard practice. For now, no change, but don’t be surprised as this gets tested in other countries. 

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