About one in 10 American adults likely have at least one food allergy, and about half of those with an allergy developed it in adulthood, says a new report published in JAMA Network Open. To obtain that estimate, researchers surveyed more than 40,000 U.S. adults.
But they also found that nearly as many Americans think they have a food allergy even though they were never diagnosed—and most of them had symptoms more consistent with a food intolerance than an allergy.
Unlike a food intolerance, a food allergy can be life-threatening; minuscule amounts of an allergen can set off an immune system reaction called anaphylaxis immediately or within a few hours. Allergy symptoms range from hives and wheezing to eyelid, face, lip, or tongue swelling, a rapid heartbeat, and difficulty breathing. Food intolerance symptoms are less severe, take longer to appear, and usually involve gastrointestinal reactions like bloating, diarrhea, and gas.
People with a severe food allergy should carry an epinephrine auto-injector like an EpiPen to prevent anaphylaxis from a food-allergen exposure. The most common food allergens are shellfish, milk, peanuts, tree nuts, fish, eggs, wheat, soy, and sesame.
What you should do
If you think you have a food allergy, don’t self-diagnose—see an allergist for testing. If you’re diagnosed with an allergy and it’s severe, the allergist will prescribe epinephrine and advise you on how to avoid contact with allergens.
A version of this article first appeared in the March 2019 issue of UC Berkeley Health After 50.
Also see New Hope for Severe Peanut Allergies.