Dr. Edmond S. Chan, MD, FRCPC (biography and disclosures)
What I did before
In 2000, the American Academy of Pediatrics (AAP) published recommendations for infants at high risk of developing allergy (first degree relative with an allergic condition). One of the primary recommendations was delaying the introduction of food protein such as peanut until 3 years of age. There were also recommendations to delay other food proteins such as egg and seafood. In the ensuing years, allergists including me adhered to this advice and counseled parents with it. Many parents still follow this advice.
What changed my practice
In the past few years, there has been accumulating research suggesting delayed introduction of food protein such as peanut has no benefit, and in fact may be contributing to an increase in peanut allergy. A study from the United Kingdom demonstrated the rate of peanut allergy there tripled when the government advised parents to delay peanut protein introduction in their children.1 Another study reported the prevalence of peanut allergy in Israeli children as one-tenth that of the United Kingdom, with the majority of Israeli infants ingesting peanut protein by 9 months of age. 2 In 2008, the AAP changed its recommendations, advising there is no convincing evidence delay of food protein such as peanut has any preventive effect. 3 What may explain this phenomenon is the “dual-allergen-exposure” hypothesis. 4 On one hand, infants with delayed introduction may have a higher chance of peanut contacting their “broken skin barrier” (eczema is a common denominator), which triggers sensitization. On the other hand, delayed introduction removes the potential benefit of early, regular, and frequent ingestion in promoting oral tolerance, through regulatory T cell pathways. A randomized study is currently underway, comparing early versus delayed peanut protein introduction in high risk infants (www.leapstudy.co.uk).
What I do now
I explain to parents and health care providers that advice to delay food proteins beyond 4 to 6 months of age to prevent allergy has been replaced by the 2008 revised AAP recommendations, indicating no benefit to delay of any food proteins beyond 4 to 6 months of age. I further explain current research is hopeful that early introduction of food protein such as peanut butter at 4 to 6 months of age may prevent peanut allergy.
Parents often ask how to introduce peanut butter at 4 to 6 months of age on the first day it is tried (no previous history of ingestion or reaction). There are no specific procedures necessary, nor have studies been done to determine the optimal amount of peanut protein to offer on the first day. Parents should introduce it like any other food they would introduce at that age. They should choose an age appropriate texture and portion size. For example, peanut butter can be given on an infant spoon or mixed with infant cereal. (Whole peanuts or chunky/large globs of peanut butter are choking hazards).
The most important message is that once introduced, frequent ingestion (e.g. daily or at least weekly) from that point onwards appears to be important for maintenance of oral tolerance.
References: (Note: Article requests require a login ID with the BC College of Physicians website or UBC)
3. Greer FR et al. Pediatrics 2008;121:183-91(View article with UBC)