Many of you may have had a double take when you read about a recent study in the New England Journal of Medicine on the benefits of feeding infants peanuts in order to reduce the risk of developing peanut allergy.
It has been hailed as landmark study that will rapidly change the guidelines for food introduction to infants. Many prominent allergy specialists have accepted these results as irrefutable and have pushed for urgent revision of all recommendations and guidelines regarding food introduction to children.
However, it is perhaps prudent to take a step back. A wise friend of mine once told me never to "eat the porridge when it is hot", meaning not to act hastily because you could burned later on. I think that "peanut allergy" is a case where that advice should really be heeded, not because the study is flawed or because the findings are not significant or exciting, but because in the grand scheme of food allergies, this finding represents only a small piece of the pie that is the mystery of how humans end up with food allergies.
The immune system is tasked with the unenviable job of deciding what is dangerous and what is not. When the body figures out what is safe and ceases to respond to a particular trigger, this is called tolerance. Immune tolerance is under the regulation of a variety of cells and chemicals within the human body. When activated, certain cells prevent an immune response while others stimulate an immune response, and it is the balance between these forces that allows us to lead healthy lives, free from the extremes of immunodeficiency and autoimmune diseases.
When it comes to food, an allergy can be thought of as an unwanted immune response in which antibodies directed against a particular food activates certain immune cells to produce chemicals that cause symptoms like hives, wheezing, vomiting or even anaphylactic shock.
The study on peanut allergy is significant because it suggests that avoiding certain foods early in life does not necessarily lead to fewer allergies to peanut. In fact, this study suggests that deliberate avoidance based on previous recommendations may be one of the reasons for why food allergies are increasing. Long ago, the original recommendation was to avoid cow's milk until 1 year of age, egg until 2, and peanut until 3 years of age. But the American Academy of Pediatrics already removed this recommendation for avoidance of foods in infancy in 2008, stating that there was no evidence that avoidance of foods prevents development of allergies.
Many have called for further updating the current guidelines based on this most recent and highly publicized study. It would be interesting to see how professional scientific groups respond to this call. Will new guidelines recommend "deliberate feeding" or "intentional exposure" of peanut during infancy, in particular between 4-11 months of age, for the purposes of preventing the development of peanut allergy? This may well reduce the incidence of peanut allergy, but certainly this excellent study deserves to be replicated and the results reconfirmed.
Moreover, there are many other unanswered questions. What about infants younger than 3 months of age? What about infants without eczema? What if he or she already had an allergy reaction to peanuts? Would administering peanut again be dangerous? What about exposure to foods by pregnant mothers? Should peanut exposure be initiated even before the birth of the baby? Is the peanut dose important? And can it be counterproductive or dangerous if you give too much? Once a patient has been exposed to and developed antibodies to a particular food, they are regarded as sensitized, though not necessarily clinically allergic. Timing of introduction of a food may be an important issue and may vary from patient to patient. One should also be wary of unintended consequences. In the internet age, many patients get their advice from search engines. A misinterpretation of new guidelines may very well result in tragic outcomes.
The human body is a very complex entity, and I cannot stress enough that parents should consult their allergist and immunologist before administering peanut to a peanut allergic child, regardless of guidelines. Without understanding the whole picture, and without knowing if their child is even sensitized, giving a child peanuts could result in unwanted serious adverse effects including anaphylaxis. A specialist can analyze potential exceptions (which are frequent and unpredictable) to the guidelines in order to make the proper recommendations for an individual child. Peanut allergy accounts for over 90 percent of all food associated anaphylaxis deaths.
Until we understand more fully about the pathogenic mechanisms involved in peanut allergy, we should not throw caution to the wind!