The benefits of regularly consuming peanut-containing foods early in life to prevent the development of peanut allergy persist even when subjects stopped peanut consumption for 1 year, a clinical study found.
Early introduction of peanuts to infants at high risk for allergy was previously shown to prevent peanut allergy. In a follow-up study, George Du Toit et al investigated whether the rate of peanut allergy remained low after 12 months of peanut avoidance among children who had consumed peanuts during the primary trial.
Du Toit et al found that among children at high risk for allergy (due to had severe eczema, egg allergy or both) who had eaten peanuts from their first year of life until they were 5 years old, a 12-month period of peanut avoidance was not associated with an increase in the prevalence of peanut allergy. The findings were published online March 4 in the New England Journal of Medicine and presented at the annual meeting of the American Academy of Allergy, Asthma and Immunology in Los Angeles.
National Institute of Allergy and Infectious Disease (NIAID) Director Anthony S. Fauci said, in a press release, that the findings “demonstrate that regular consumption of peanut-containing foods beginning in infancy induces peanut tolerance that persists following a year of avoidance, suggesting the lasting benefits of early-life consumption for infants at high risk of developing peanut allergy.”
CBS News explained the initial finding had turned decades of conventional wisdom on its head. For years, doctors had advised parents to delay feeding their infants foods that might prompt allergic reactions until they got older. Now, the latest part of the study shows that this protection against peanut allergies lasts for at least a year—even if the children stopped eating foods containing peanuts.
CBS News wrote that after the year without peanuts, there was only a slight increase in risk of peanut allergy among the children who had consumed peanuts during first study period, from 3.6% to 4.8%. This increase was not statistically significant. On the other hand, peanut allergy developed in 18.6% of children who had avoided eating peanuts since their first year of life. Data sets for these analyses are accessible through TrialShare, a public website managed by the Immune Tolerance Network.
Following the original study, the American Academy of Pediatrics revised their recommendations to prevent peanut allergies in high risk infants and endorses giving them food containing peanuts before their first birthday.
The New York Times wrote that the NIAID had proposed guidelines recommending that children at risk for peanut allergies be fed peanuts starting at 4 to 6 months of age, though they should be tested first to make sure they do not already have an allergy.
“Further studies are needed to determine the longer term effects of intermittent ad lib peanut consumption following introduction early in life,” said the study’s senior author Gideon Lack. “Parents of infants and young children with eczema or egg allergy should consult with an allergist, pediatrician or their general practitioner prior to feeding them peanut products.”
The Times also reported that the researchers conducted a separate study of 1300 infants who were 3 months old and being fed only breast milk. Half were randomly assigned to continue on only breast milk until 6 months of age, and the other half were to be regularly fed small amounts of peanut butter and 5 other allergenic foods: eggs, yogurt, sesame, white fish, and wheat. The children were assessed for allergies when they turned 3.
Overall, 5.6% of the infants who were fed the allergenic foods early on developed an allergy to at least one of the 6 foods—slightly but not significantly lower than the 7.1% in the breast milk-only group.