Food Allergies Less Common Than Believed

Food Allergies Less Common Than BelievedFood allergies are not as common as thought, as many who believe they are allergice to certain foods, are actually not so.

A new report commissioned by the federal government has found the field to be rife with poorly done studies, misdiagnoses and tests that give misleading results.

According to Dr. Marc Riedl, an allergist and immunologist at the University of California, Los Angeles and author of the new paper, undoubtedly, people can be allergic to certain foods, with a range of responses from a rash to a severe life-threatening reaction, however, the true incidence of food allergies is only around 8% for children and less than 5% for adults.

Yet, around 30% of the population believe they have food allergies, and Dr. Riedl said, around half of the patients coming to his clinic believed they had a food allergy when they didn’t, because they had been told so.

People who have food allergies as children, may have shed them as adults. And, just as people shed allergies for no known reason, just the same way they may develop food allergies as adults for unknown reasons.

Dr. Reidl and his colleagues reviewed over 12,000 articles on food allergies published between January 1988 and September 2009, finding only 72 that met their criteria of having sufficient data for analysis and had used rigorous tests for allergic responses. They did not just prick the skin and inject a small amount of suspect food, looking for for IgE antibodies, the type associated with allergies in the blood. Investigators found they have less than a 50% chance of actually having a food allergy.

The paper will be published in The Journal of the American Medical Association and is a part of a bigger project organized by the National Institute of Allergy and Infectious Diseases. An expert panel will provide guidelines defining food allergies, including criteria for diagnosing and managing patients, which final draft should be ready by the end of June.

Part of the confusion is what is a food allergy and what is a food intolerance. While, allergies involve the immune system, intolerances generally do not. For instance, a headache brought on from sulfites in wine is not a food allergy, but an intolerance. As in lactose intolerance, caused by the lack of an enzyme required for digesting the sugar in milk.

As well, people often mistake other medical conditions as food allergies, such as, interpreting acid reflux symptoms after eating a particular food as an allergy.

During the development of an allergy, the immune system reacts to certain food proteins, producing IgE antibodies. The higher the levels of IgE antibodies to a particular food, the greater the likelihood the person will react in an allergic way.

More than half of all allergies to foods result from cow’s milk, hen’s eggs, peanuts, tree nuts, fish and shellfish, which foods are what the study focused on.

Region: