Introducing peanuts early to the diet of infants significantly reduces their risk of peanut allergy until six years of age, even if they stop eating peanuts around the age of five, a new study has claimed.
Researchers from King's College London followed on from the LEAP (Learning Early About Peanut Allergy) study and found that the majority of infants at high-risk of developing peanut allergy are protected from it at age 5 years if they eat peanuts frequently, starting within the first 11 months of life.
All participants in the LEAP-On study were instructed to avoid peanut for 12 months after they had completed the LEAP study, regardless of whether they had been randomised to avoid or eat peanuts 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 questionnaires, 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 randomised to peanut avoidance and 270 to peanut consumption on the LEAP study; adherence to these interventions was high at 92 per cent.
All participants were asked to avoid peanut during LEAP-On and adherence during this study was also high - 90.4 per cent for previous LEAP avoiders and 69.3 per cent for previous LEAP consumers.
The study found that at 6 years of age, there was no statistically significant increase in allergy after 12 months of avoidance, in those who had consumed peanut during the LEAP trial.
The study also found that peanut allergy was significantly more prevalent in those who had avoided eating peanuts in LEAP, than those who consumed.
There were only 3 subjects from the consumer group who developed new peanut allergy during the 12 months of peanut avoidance, but there were also 3 subjects from the avoidance group who developed new peanut allergy.
The findings show 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, researchers said.
Overall, the study saw a 74 per cent relative reduction in the prevalence of peanut allergy in those who consumed peanut compared to those who avoided, they said.
The findings were published in the New England Journal of Medicine.
