The early introduction of peanut to the diets of infants at high-risk of developing a peanut allergy notably reduces the risk of peanut allergy until age 6.
Published today in the New England Journal of Medicine, the LEAP-On study followed on from the LEAP (Learning Early About Peanut Allergy) study, both led by Professor Gideon Lack at King’s, which found that the majority of infants at high-risk of developing peanut allergy are protected from peanut allergy at age 5 years if they eat peanut frequently, starting within the first 11 months of life.
LEAP-On asked whether those infants who had consumed peanut in the LEAP study would remain protected against peanut allergy if they then stopped eating peanut for 12 months. The study findings conclude that the early introduction of peanut protects against the development of peanut allergy, and such protection is sustained even when peanut is no longer consumed for 12 months.
The LEAP-On study was undertaken at Evelina London Children’s Hospital, and enrolled 556 participants from LEAP (out of a total of 628), of whom 550 had a complete primary outcome. All participants were instructed to avoid peanut for 12 months after they had completed the LEAP study, regardless of whether they had been randomized to avoid or eat peanut in the LEAP study. At the completion of LEAP-On, a rigorous clinical assessment of peanut allergy was made by oral peanut challenge. Additional peanut allergy assessments were made by questionnaire, skin prick test (SPT), and peanut-specific immune markers IgE and IgG4 were also measured in participants’ blood.
Of the 550 LEAP-On participants, 280 had been randomized to peanut avoidance and 270 to peanut consumption on the LEAP Study; adherence to these interventions was high at 92%. All participants were asked to avoid peanut during LEAP-On and adherence during this study was also high: 90.4% for previous LEAP avoiders and 69.3% for previous LEAP consumers.