FOOD+NUTRITION By Caroline Shermer, MS, RDN, LDN
What’s the Difference Between Food Allergies, Intolerances, and Sensitivities? When pursuing health and wellness, it’s important to tune into how food, exercise, and emotions feel in the body. Food allergies, intolerances, and sensitivities can have a major impact on a person’s quality of life and, in recent years, have increasingly led individuals to exclude more and more foods. The decision to exclude certain foods may be diet culture driven, a medical necessity, or somewhere in between. Are these exclusions always necessary or beneficial? To get to the bottom of this question, it’s imperative to decipher the differences between food allergies, intolerances, and sensitivities.
Food Allergies 32 million Americans have food allergies. The eight most common food allergens— accounting for 90% of all food allergies— include milk, egg, peanut, tree nut, soy, wheat, fish, and shellfish. In a food allergy reaction, the immune system registers a harmless food as dangerous and begins to attack, leaving the individual with symptoms such as digestive problems, a swollen airway, hives, or possibly even anaphylaxis. A person’s reaction can vary from one exposure to another, so it is best to completely abstain from food allergens. When a food allergy is suspected, expect to be referred to an allergist or immunologist for testing. Diagnostic tests may include skin prick tests, oral food challenges, or IgE blood work. Ig stands for immunoglobulins or antibodies, which are found in the body and are markers of an immune response. It’s important to distinguish between IgE and IgG immunoglobulins as outlined in the chart to the right:
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Immunoglobulin
What It Tells Us
Key Point
IgE
After blood is drawn, the sample is sent to a lab for testing of various foods with the blood sample to measure IgE levels.
An elevated IgE response is indicative of an allergy or allergic response. IgE blood work can serve as part of the diagnostic plan for food allergies.
IgG
Most antibodies in the blood are IgG. These antibodies develop after exposure to a food or other foreign body.
IgG blood work proves exposure and shows tolerance, not allergy. These tests are not valid or reliable for the diagnosis of a food allergy, intolerance, or sensitivity.
Note: Applied kinesiology, hair analysis testing, and mediator release assay are not evidence-based methods in the diagnosis of food allergies, intolerances, or sensitivity.
