The prevalence of peanut allergy has doubled over the past ten years in the US and other various countries, especially those which promote the avoidance of peanuts during pregnancy, lactation, and infancy. Rates of peanut allergy have reached 1.4-3.0%, particularly in Western countries. Having a child with a peanut allergy is life-changing, difficult, and nothing short of terrifying due to the fatal consequences involved. The LEAP study, also known as the “Learning Early About Peanut Allergy” study, sought to test how early vs. late introduction of peanuts to infants who are at high-risk for developing a peanut allergy effects the infant’s development of the allergy. This study was based on the hypothesis that “regular eating of peanut-containing products, when started during infancy, will elicit a protective immune response instead of an allergic immune reaction.”
The LEAP study was the first randomized trial which focused on the prevention of food allergies in a large cohort of high-risk infants. The study tested over 600 children at 4-11 months old who were at high risk for peanut allergy. These children were randomized to either consume or avoid peanuts until age five so that a comparison of peanut allergy incidence could be be made between the two groups. As a result, of the children who avoided peanuts, 17% developed peanut allergy by the age of 5 years, while only 3% of the children who consumed the peanut snack developed allergy by age 5. Therefore, in high-risk infants, early introduction of peanuts was highly effective in preventing the development of peanut allergy. According to Professor Lack, the main investigator of the LEAP study, “for decades allergists have been recommending that young infants avoid consuming allergenic foods such as peanut to prevent food allergies." This study proves that those recommendations may in fact be incorrect, and may possibly be the cause of the high prevalence of allergies in children today.
Overall, the LEAP study showed that “early, sustained consumption of peanut products was associated with a substantial and significant decrease in the development of peanut allergy in high-risk infants.” On the other hand, peanut avoidance was associated with a greater prevalence of peanut allergy than was peanut consumption, which questions original recommendations of deliberate avoidance of peanuts as a strategy to prevent allergy.
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