Food allergies are frequently overdiagnosed because the two tests commonly used have less than a 50% accuracy rate, according to a new authoritative study. As a result, whereas three in ten adult Americans think they have one or another food allergy, the actual number is more on the order of one in twenty (5%) adults, and a little higher for children (8%).
The new study was sponsored by the National Institute of Allergy and Infectious Diseases, a branch of the NIH, and was reported in the Journal of the American Medical Association.
The skin prick test and the antibody test are the two main tests done for food allergies, but the only real way to know if someone has a true food allergy is to challenge their body by slipping them a small amount of the food and seeing if a rash or even bigger reaction results. That’s a scary prospect for many patients, so the food challenge test is seldom done.
Another issue is that many people have a food intolerance — like lactose intolerance due to a missing enzyme that breaks down sugar in milk — but that is not the same as a food allergy, which happens when the person’s immune system goes haywire in response to an allergen.
This study reinforces advice I give in my book, “The Life You Save.” I don’t think anyone should make major changes in their life based on one or two test results without making really sure that they have the condition. That can mean confirmatory testing, a second opinion, or just plain education so that you understand that no test result is 100%.