What's the Difference Between a Food Allergy and Food Intolerance? Here's What Most Americans Don't Know
According to a recent study, most of us don't know the difference between a food allergy and an intolerance.
With the rise of gluten-free and dairy-free diets over the past few years, food allergies and intolerances appear to be surging now more than ever. Celebs like and have famously stripped their diets of common allergenic foods in the name of health, and the public seems eager to follow suit. Have we become better at detecting food allergies and intolerances, or are they just the latest trend?
A new study published in JAMA Network Open suggests many Americans’ food fears may be “unfounded.” After reviewing data collected from over 40,000 U.S. adults, the researchers found about —and only about 10% actually had one.
"While we found that , nearly twice as many adults think that they are allergic to foods, while their symptoms may suggest food intolerance or other food-related conditions," lead study author Ruchi Gupta, MD, MPH, of the Northwestern University Feinberg School of Medicine, explained in a press release.
While these adults may actually believe they have a food allergy, the symptoms they reported were not reflective of true allergic reactions. Most likely, they were experiencing other unwelcome symptoms—like diarrhea, abdominal pain, or bloating—from a food sensitivity or intolerance. Food allergy symptoms are caused by an immune system response; symptoms of intolerances or sensitivities are not. Someone with a food intolerance is missing a digestive enzyme that would break down a part of the offending food. Food sensitivities aren't as clearly defined, but they usually involve an upset stomach after eating a specific food.
Julie Upton, RD, co-founder of , explains that when a person has a full-blown food allergy, “the body's immune system overreacts to proteins that [their bodies perceive as] unhealthy and attacks them as a threat to the body. The reaction to this faulty immune response leads to symptoms like itching, welts on your skin, breakouts, tightening of your throat, or shortness of breath.”
At worst, allergic responses can result in a life-threatening reaction called anaphylaxis, which requires immediate medical attention. On the other hand, a food sensitivity can cause discomfort, but does not pose a threat to your health, Upton says.
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So why are so many Americans under the false impression that they have a food allergy? Upton says this can be the case for a variety of reasons, but often people use allergies as a way to avoid certain foods they consider unhealthy. “In my work, I most often see extremely healthy eaters who claim to be allergic to things like sugar [which is extremely rare], dairy, wheat, or gluten," she says. "In almost all cases they aren't allergic or even sensitive to these foods, but they claim to be in order to have more control over their daily diet and what they may perceive as a more healthful approach to eating."
She also mentions false food allergy claims could be the result of an unhealthy relationship with food or a desire to feel different by identifying with an allergy.
If you think you may have a food allergy, Dr. Gupta urges people to “see a physician for appropriate testing and diagnosis before completely eliminating foods from the diet.” Upton adds that elimination diets, an eating plan in which foods are cut out and slowly added back into your diet to find potential allergens, “need to be conducted with the aid of a dietitian or allergist.”
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