When physicians or dietitians refer to such issues, they’re more likely to use the term food intolerance, Dr Stukus said (though some may use food sensitivity, too), like with lactose intolerance, which can cause constipation, diarrhoea and bloating as a result of difficulty digesting the sugar found in milk. Similarly, people with irritable bowel syndrome may be sensitive to certain kinds of carbohydrates called FODMAPs, and altering their diet may relieve their symptoms.
A food intolerance or sensitivity is different from a food allergy, Dr Stukus said, which is an immune reaction to certain foods that can cause more severe symptoms like vomiting, hives, shortness of breath or even life-threatening anaphylaxis, usually within minutes of eating even a small amount. There are also more chronic immune reactions to foods, like those from celiac disease, a serious autoimmune condition triggered by gluten.
HOW DO FOOD SENSITIVITY TESTS WORK?
At-home food-sensitivity test kits can be ordered online or purchased over-the-counter at drugstores. Depending on the test type, you’ll pluck several hairs or prick your finger to drop blood onto a paper card, and then mail in your sample. Within days or weeks, you’ll receive digital results, including a list of foods that may be causing problems.
Some tests claim to determine your sensitivity to hundreds of foods and ingredients by measuring the “bioresonance” of your hair, an unproven technique used in holistic or complementary medicine that involves measuring the energy wavelengths coming from your body. Others measure the levels of certain antibodies, called IgG antibodies, in your blood.
Still other tests, called Alcat and MRT tests, require a blood draw from a lab and measure how the size of your blood cells change after exposure to food extracts in a test tube, said Dr John M. Kelso, an allergist at Scripps Clinic Carmel Valley in San Diego.
ARE FOOD SENSITIVITY TESTS ACCURATE?
Aside from the breath tests that gastroenterologists sometimes use to diagnose certain intolerances, like those to lactose or fructose, there aren’t validated tests for food intolerances or sensitivities, said Tamara Duker Freuman, a registered dietitian at New York Gastroenterology Associates in New York City. The only way to figure out if you are sensitive to certain foods or ingredients is to see how your symptoms change after eliminating them from your diet, ideally with the help of a registered dietitian or physician, she said.