Discussing the 'Peanut Study' with an Allergy Doctor
After a decade of research, the National Institute of Allergy and Infectious Diseases and the Immune Tolerance Network released the long-awaited results of their LEAP Study -- that is, Learning Early About Peanut Allergy. The clinical trial looked at 640 children between four and 11 months old who were at a high risk of developing a peanut allergy to see if feeding them peanuts early in life would prevent them from developing an allergic reaction.
In short: Yup.
The children were split into two groups, one that ate peanuts and one that didn't. Of the children who avoided peanuts, 17% developed a peanut allergy by five years old. Of the group that ate peanuts, only 3% of them did. This is a huge deal.
I spoke with Dr. Sharon Chinthrajah, from Stanford's Division of Immunology and Allergy, Department of Pediatrics Pulmonary and Critical Care, about the study.
Does this mean that other allergenic foods may work the same way?
Dr. Chinthrajah: We don't know. It kind of changes the paradigm of how we think about early introduction of foods. I think there will likely be some recommendations by the American Academy of Pediatrics Society for whether or not to introduce foods early. One likes to think that early introduction of different types of allergenic foods might prevent the development of food allergies, certainly for peanuts, and potentially for tree nuts, milk, eggs, soy, wheat.
Why does this method of early dosage work?
Dr. Chinthrajah: One of the factors of developing peanut allergies is probably when you're introduced to the food. While your body is developing its immune system, it also needs to be exposed to different foods to learn they are not harmful, that your body does not have to mount a dangerous response. Maybe that early exposure educates the immune system. But I don't think that's necessarily the whole picture. Certainly you have adults and older kids who have eaten those foods earlier in their lives without any sort of reaction and then develop those allergies. Certainly we've seen through history that some individuals are just more an allergic type of individual. So even early introduction won't help everyone from developing a peanut allergy.
Would this information help adults who have food allergies?
Dr. Chinthrajah: This is just to look at preventing food allergies. Even the kids in the study, they did food allergy tests to begin with to make sure these kids were not having an allergic reaction to peanuts, that it would be safe for them to eat peanuts at home if they were assigned to that arm of the study. If you're allergic, those kids were excluded. And certainly adults or older kids who have a peanut allergy, this would not be the way that we would go about that. This is not a treatment option for them. There are clinical trials that we're doing at Stanford and other places in the world to help as a therapy for people with food allergies, and that involves taking really small doses of whatever somebody is allergic to, exposing them in a research setting, increasing those doses over time, and taking a dose every single day to slowly reeducate your immune system.
How important does this new study rank in relation to other food studies?
Dr. Chinthrajah: It's huge because of the sheer number of patients they studied, and second of all because this really does shift the paradigm of when we think about introducing foods. Certainly for peanuts, but potentially also other allergenic foods. Also, there's a follow-up study to this study, because potentially, in the group that had the positive skin test, they were already sensitized to peanuts. Perhaps those kids were just getting desensitized by eating peanuts on a regular basis, so we're going to see if these kids can tolerate peanuts after they avoid peanuts for a period of time, and then re-challenge them to see if this is really a permanent immune response.