Infants who eat peanuts within the first 11 months of life are less likely to develop peanut allergies, even if they take a break from eating the nuts when they're older, according to a new study.
Called the LEAP-on study, it followed a study called LEAP (Learning Early About Peanut Allergy) in which approximately 600 children were examined for peanut allergies. In the LEAP study, about half of the children avoided peanuts and the other half were advised to eat peanuts during their first year of life.
Researchers found out that among the children who avoided peanuts, 35 percent tested positive for a peanut allergy with a skin prick test, whereas among the children exposed to peanuts, just 11 percent tested positive for the allergy.
For the LEAP-on study, which was published today in the New England Journal of Medicine, researchers examined 556 children involved in the LEAP study to see if there were effects of avoiding peanuts for a year later in life.
Researchers had both groups -- those who ate peanuts early in life and those who did not -- stop eating any peanut products for a year starting at age 5. About 18.6 percent in the peanut-avoiding group and 4.8 percent of the peanut-consuming group showed an allergy to peanuts at the beginning of the second study.
"The aim of our study was to find out whether infants who had consumed peanut in the LEAP study would remain protected against peanut allergy after they stopped eating peanut for 12 months," Professor Gideon Lack, lead author of the study and head of pediatric allergy at King's College London and head of the Children's Allergy Service at Guy's and St. Thomas' National Health Service Foundation Trust, said today.
"LEAP-on clearly demonstrates that the majority of infants did in fact remain protected and that the protection was long-lasting," he said.
The study authors found that there was no statistically significant increase in the number of children who developed a new peanut allergy after avoiding the nuts for a year. Three children from each group developed a peanut allergy by the end of the year.
The study authors said more work is needed to be done to understand how the amount of peanuts consumed affects allergy risk.
"We need more research to better understand the mechanisms behind the development and prevention of allergic responses to peanut, and how this might translate to other food allergies," Dr. George Du Toit, co-investigator of the study and consultant in pediatric allergy at Guy's and St. Thomas' NHS Foundation Trust, said in a statement.
"However, it is reassuring that the highly protective intervention demonstrated in LEAP was not only safe, nutritionally favorable and acceptable to participant families but also sustained even with cessation of peanut consumption for 12 months," he said.
Peanut allergy has been a growing problem in the U.S., according to the American College of Allergy Asthma and Immunology.
Dr. Lolita McDavid, a pediatrician at University Hospitals Rainbow Babies and Children’s Hospital, said the study reaches some important findings.
"Why these studies are important is the global allergy to peanuts has been growing," McDavid said. "This was not seen in the past. There are a lot of cultures where peanut is a staple in the diet."
Parents who want to desensitize high-risk children to peanuts should talk to a doctor so that children don't have a dangerous reaction to eating peanuts, she said.
"Talk to a pediatric allergist and they can do a skin prick test and you can find out whether they’re allergic or not," McDavid said.
Exposure to peanuts in high risk children or those with signs of peanut allergies needs "to be done under a doctor’s supervision. You have to have an epipen available."