Last week the headlines all boasted that feeding babies peanuts could prevent peanut allergies. A new study in the New England Journal of Medicine assigned children thought to be at high risk for peanut allergy development to either an exposure group or an avoidance group. It was found that 10.6% of the infants in the exposure group tested positive for peanut allergy at 60 months of age, versus 35.3% of infants in the avoidance group. I’m not quite as convinced as the headlines that this is a cure for peanut allergy. Certainly, there was a large difference between groups. However, we have seen in previous research that peanut exposure in allergic children may increase tolerance, although not to the extent that they would be able to safely munch on a peanut butter and jam sandwich for lunch.
This may be a matter of semantics, and it’s purely my own interpretation, but I think that the current study provides more support for the stance that peanut (and likely other allergens) avoidance in at risk children increases the likelihood of allergy development. More so than the consumption of peanuts decreases the risk of peanut allergy.
Peanut allergy does not occur upon the first exposure to peanuts. It usually occurs upon the second exposure. Although it may occur upon subsequent exposures, this is unlikely in the case of peanut allergy. I can’t help but wonder how this may have effected the results. The authors don’t mention whether or not the infants in the study had been exposed to peanuts prior to enrolment. I can’t help but wonder if this could have affected the results in some way. There is also the question as to whether the withdrawal of infants from the study was a result of the development of peanut allergy in the consumption group, or perhaps discovery of the absence of allergy in the avoidance group. Could this have significantly affected the results? Adherence was quite good, over 90% in both groups, however, reasons for withdrawal could still have an impact on the results.
While the infants included in the study were all identified as being at risk of developing peanut allergies due to either the presence of eczema and/or egg allergy, these are not necessarily the best ways to identify risk. The children at greatest risk of developing peanut allergy are those who have an immediate family member (i.e. a parent or sibling) who has a peanut allergy. The children in the study would be at greater risk than those without eczema or other allergies but they would not necessarily be those at greatest risk. Perhaps infants at greatest risk would benefit from early peanut exposure, perhaps not. Perhaps infants in the general population would benefit from early peanut exposure, perhaps not.
Okay, so, I’m sure that parents are wondering what all of this means. Firstly, what many of the news articles are failing to impart is that the current guidelines recommend waiting until 6 months of age before introducing solids. Introducing peanuts, or any solid foods, at younger ages is not recommended as infants do not have fully developed digestive systems. Peanuts and peanut butter may also be choking hazards for infants, please be sure to use age appropriate foods and supervise your infant during feeding. Finally, this research supports the current guidelines which indicate that there is no reason to avoid providing your infant potentially allergenic foods at the same time that you introduce other foods. Regardless as to whether or not early introduction reduces the risk of allergy development or later introduction increases risk, at this point we know that there is no benefit to waiting, and there may be disadvantages to doing so.