Randomised controlled trial of brief neonatal exposure to cows' milk on the development of atopy.

OBJECTIVE To determine the effect of brief early exposure to cows' milk on atopy in the first 2 years of life. DESIGN Double blind, placebo controlled, randomised feeding intervention trial (Bokaal study). SETTING Dutch midwifery practices. PARTICIPANTS 1533 breast fed neonates. INTERVENTION Exposure to cows' milk protein (n = 758) or a protein free placebo (n = 775) during the first 3 days of life. MAIN OUTCOME MEASURES Clinical atopic disease and any positive radioallergosorbent (RAST) tests at 1 year of age. RESULTS Atopic disease in the first year was found in 10.0% (cows' milk) v 9.3% (placebo) of the children, with a relative risk of 1.07; in the second year, atopic disease was found in 9.6% v 10.2%, respectively, with a relative risk of 0.94. Per protocol analysis showed similar results. Any RAST positive test was found in 9.4% (cows' milk) v 7.9% (placebo) of children, with a relative risk of 1.19. Stratified analysis for high family risk of allergy showed a doubled incidence of atopic disease but no effect from the intervention. CONCLUSION Early and brief exposure to cows' milk in breast fed children does not increase the risk of atopic disease in the first 2 years.