Here's What You Need To Know About At-Home Tests For Food Intolerances

by Melissa L. Fenton
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Remember when the only home diagnostic medical test available at your local pharmacy was a pregnancy test? Times have changed, and with it, so have at-home medical testing technologies — which means the average person now has the ability to self-diagnose a whole variety of medical maladies right in the comfort of their own homes.

From thyroid function to metabolism, from cardiovascular health to confidential AIDS tests, and all the way to sending off your poop to be screened for colon cancer markers, today’s health consumers are taking full advantage of these modern home conveniences at increasing rates.

But one such test — which has seen a huge increase in popularity over the last few years — might need to be taken with a grain of salt. Sometimes literally. I’m referring to at-home food intolerance, food sensitivity, and food allergy tests that are being heavily marketed now.

First, let’s talk about the very significant difference between a food intolerance and a food allergy. Food allergies are serious and potentially life-threatening reactions to certain foods, and directly involve and engage your body’s immune system. The ingestion of even the smallest amount of a food allergen can send someone into anaphylactic shock. It’s estimated that 15 million Americans have a food allergy, and with one in every 13 children having one—that’s about 2 in every U.S. classroom.

A food intolerance, on the other hand, is when someone has difficulty digesting a certain food. These digestive difficulties manifest themselves in the form of bloating, gas, intestinal distress, diarrhea, and abdominal pain.

Food allergies are serious medical conditions that need to be diagnosed and evaluated by a medical professional, and are typically diagnosed after extensive skin prick tests, blood tests, and something called a “food challenge” (introducing small amounts of suspect food over a period of time) all of which should be done under the care of an allergist, not at home. Your allergist will use a immunoglobulin E (IgE) test — which measures the specific level of the antibody IgE in your blood after exposure to suspected allergen.

Food intolerances and a specific “food sensitivity” (a term that wasn’t even used before 2012) can be just as difficult to diagnose, making this new wave of at-home testing kits a bit suspect. The test-at-home kits use a blood sample and are immunoglobulin G (IgG) tests — meaning they’re examining a cell’s inflammatory response to certain foods. The thinking being, if your cells send up an inflammation signal, that should be a food you may want to avoid.

Sounds reasonable, right? Well, physicians say not so fast, and this is why: A cell’s inflammatory response may actually be an indicator of tolerance to, not against, that food. Additionally, because these tests can be testing for over 100 foods, both false positives (showing a response without any intolerance symptoms) and false negatives are common.

Purvi Parikh, an allergist and immunologist with the Allergy and Asthma network states, “When you’re testing for everything, it’s really easy to get a false positive.” False negatives can also be lethal. For example, someone with a peanut allergy may not show an inflammatory response with the IgG test (but would with the IgE test), and may think it’s safe to ingest peanuts.

The American Academy of Allergy Asthma and Immunology (AAAAI), the European Academy of Allergy and Clinical Immunology (EAACI), and most recently the The Canadian Society of Allergy and Clinical Immunology (CSACI) have all released statements on the growing trend of at-home food intolerance and sensitivity tests, and the potential dangers and inaccuracies they possess. The CSACI states, “There is no body of research that supports the use of this test to diagnose adverse reactions to food or to predict future adverse reactions.” And both the AAAAI and the EAACI warn about “the inappropriate measurement of food-specific IgG or IgG4 to suggest the presence or potential of adverse reactions to food,” and add, “Recent guidelines emphasize that such testing plays no role in the diagnosis of food allergy or intolerance.”

Before attempting to self-diagnose a food allergy or intolerance in yourself or your children, do your research and talk with your doctor, allergist, a homeopathic practitioner, or a licensed dietitian/nutritionist. This way you can ensure your condition is being diagnosed in the most applicable and appropriate way, and you can begin treatment or an elimination diet to reduce your symptoms and find the root cause of your discomfort.

Because food allergies — and even food intolerances — are nothing to mess around with.