Can the risk of later peanut allergy be reduced in infancy?

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The American Academy of Pediatrics previously advised parents to keep infants away from peanuts until they were at least 36 months old. However, in 2008, the AAP retracted that

peanutsThe American Academy of Pediatrics previously advised parents to keep infants away from peanuts until they were at least 36 months old. However, in 2008, the AAP retracted that statement saying evidence did not support this strategy as a method of reducing risk of food allergy. And now, a new study finds that introducing peanuts, under careful medical and parental supervision, at an early age in those infants at high risk of developing peanut allergy may actually reduce their risk of developing it. This has could be lifesaving, given that the rate of peanut allergies has tripled over the past twenty years according to the Centers for Disease Control and Prevention.

Researchers from King s College London and Guy s and St. Thomas National Health Service Foundation Trust in the United Kingdom conducted a study of 640 infants between the ages of four and eleven months who were at an increased risk of peanut allergy because of severe eczema, egg allergy or both. Known as LEAP the Learning Early about Peanut Allergy trial researchers randomly assigned children to either a peanut consumption or avoidance group. All children were given an initial skin-prick test and those in the consumption group were administered a food challenge in which they were given peanut protein. Those who had a reaction to the food challenge were moved to the avoidance group. Children in the consumption group were given six grams of peanut protein a week until the age of sixty months, at which point both groups were tested for peanut allergy.

Researchers looked at children in two groups: Those who had demonstrated no sign of peanut allergy at the beginning of the study and those who had demonstrated some sign of peanut allergy at the beginning of the study.

Among those children who had demonstrated no sign of peanut allergy, at 60 months, 14 percent of those in the avoidance group developed a peanut allergy at five years, but only about two percent of those in the consumption group became allergic. This amounts to an 86 percent reduction in risk of developing peanut allergy. Among those children who had demonstrated some sign of peanut allergy initially (a positive skin-prick test), about 35 percent of those in the avoidance group developed a peanut allergy at five years, but only about 11 percent of those in the consumption group became allergic. This amounts to a 70 percent reduction in risk of developing peanut allergy. Researchers add that there were no deaths during the study or differences in adverse events or hospitalizations between the consumption and avoidance groups.

Although questions such as how much peanut protein children should consume, how frequently and for how long should children consume this protein, and will they remain protected after ceasing such consumption, in an accompanying editorial, Drs. Hugh Sampson and Rebecca Gruchalla from the University of Texas Southwestern Medical Center at Dallas use this study to call for a change in guidelines: The LEAP study makes it clear that we can do something now to reverse the increasing prevalence of peanut allergy. Because the results of this trial are so compelling and the problem of the increasing prevalence of peanut allergy so alarming, new guidelines should be forthcoming very soon.

ACSH s Dr. Gilbert Ross adds, The results of this study are very promising, but, at the moment, parents should not attempt to replicate this experiment with their children at home, as exposure to peanuts for some could be life threatening.

He goes on, These results bring to mind the hygiene hypothesis, which states that lack of exposure to germs and other immunogenic substances at a young age interferes with natural development of the immune system in the children and consequently an increase in conditions related to the immune system.

ACSH friend Lenore Skenazy has summed up the problems with lack of exposure very well: Being obsessive about child cleanliness is like being obsessive about stranger danger. When we see all germs and humans as a threat to our kids and try to keep them at bay, our children end up not being able to distinguish between the normal and the dangerous. Their systems over-react to the whole, great smorgasbord of the world, often reflexively flinching at dander, peanuts and the lady who says Hello! to them as they wait at the bus stop.