Can Early Peanut Consumption Reduce Development of Peanut Allergies in Kids?
Title: Randomized Trial of Peanut Consumption in Infants at Risk for Peanut Allergy
Author: Du Toit et al
Journal: New England Journal of Medicine (Feb 26, 2015; 372; 9)
Objective: To determine whether the early introduction of dietary peanut could serve as an effective primary and secondary strategy for the prevention of peanut allergy.
Peanut allergy is an occasionally life threatening condition that has garnered major public attention recently, leading to changes in food consumption rules. The most severe presentation is life-threatening anaphylaxis which can include airway constriction and death.
In Western nations, peanut allergies have increased from 1.4% to 3.0% in just 10 years. As a result of the way the immune system works, these allergies tend to persist into adulthood and remain. Management and treatment of this problem has been primarily mediated through an avoidance strategy by most pediatricians, although whether it is superior to an early exposure strategy is previously unknown.
Interestingly, a comparison of British-Jewish children, who do not consume peanuts early in infancy, compared to Israel-Jewish children of similar ancestry who do consume them, demonstrated a significantly lower rate of peanut allergies in the Israeli children.
This lead to researchers hypothesizing that early introduction of peanuts could offer protection from developing a peanut allergy.
They randomly assigned 640 infants with severe eczema, egg allergy, or both to either consume or avoid peanuts until 60 months of age.
Participants, who were between 4 months and 11 months of age at randomization, were assigned to separate study cohorts on the basis of preexisting sensitivity to peanut extract, which was determined with the use of a skin-prick test — one consisting of participants with no measurable wheal after testing and the other consisting of those with a wheal measuring 1 to 4 mm in diameter.
The primary outcome, which was assessed independently in each cohort, was the proportion of participants with peanut allergy at 60 months of age.
Amazingly, among the 530 infants who initially had a negative sensitivity test to peanuts, the prevalence of peanut allergy at 60 months of age was 13.7% in the avoidance group and 1.9% in the consumption group (P<0.001).
Among the 98 participants who initially had positive test results, the prevalence of peanut allergy was 35.3% in the avoidance group and 10.6% in the consumption group (P = 0.004).
There was no significant between-group difference in the incidence of serious adverse events.
Increases in levels of peanut-specific IgG4 antibody occurred predominantly in the consumption group; a greater percentage of participants in the avoidance group had elevated titers of peanut-specific IgE antibody.
Very impressively, early exposure in infants to peanut butter, rather than keeping peanuts away from them, offered a protective effect for 80% of children at high risk of developing an allergy.
In children who were not high risk, there was a greater than 85% reduction.
This is a landmark study that will likely change the entire management of allergies from an avoidance approach to a preventative approach.
The world of pediatrics and allergy will move swiftly to see if this approach extends to other allergens like eggs, dairy, etc.