Up to a third of people in the United States believe they have a food allergy, according to The Journal of the American Medical Association.
But only 5 percent of children and 4 percent of adults actually have a diagnosed food allergy. Most people don’t understand the nature of a true allergy and they often misuse the term. “Unfortunately the term ‘allergy’ is sometimes used by the public or health care providers to describe any unpleasant experience patients have with eating food, including ‘feeling bad’,” explained Marc Riedl, M.D., M.S.
Anatomy of a Food Allergy
A food allergy has a specific immune system response. It involves either immunoglobulin E (IgE) or T-cells. Both are from a reaction food protein. The IgE reaction occurs within minutes, sometimes hours, of smelling, touching, or ingesting a particular food. The presence of the protein causes the immune system to overreact and interpret the food as harmful. Histamine is released by the body causing hives, itching, trouble breathing and, rarely, anaphylaxis.
A non-IgE immune system reaction can occur hours after ingestion and can be mistaken for food sensitivity or food poisoning. “The biggest misunderstanding is that there are different types of food allergies, they’re reproducible, the reactions are the same,” explained Wesley Burks, M.D., division chief of pediatric allergy and immunology at Duke University Medical Center in Durham, N.C. “You can’t eat cheese, feel sick, and claim a food allergy, but then turn around and enjoy ice cream and feel ok. With a true food allergy, the trigger does not change and the trigger will always set off the same immune response.”
Intolerance vs. Food Allergy
Food intolerance happens when the body lacks an enzyme to digest a certain food. You can avoid ingesting food that causes the reaction, but these reactions are not caused by the immune system like in an allergy. They are not life-threatening.
Food sensitivity generally refers to an unpleasant reaction to a certain food. Acid reflux, nausea, or abdominal cramps may occur, but these are not immune responses.