As I get older, I find that I just can’t eat like I used to. I spent my whole life with an ironclad stomach only to not so gracefully discover in my 30s the adverse effects of eating certain types of dairy, or spicy stuff, or anything just a little bit too sugary. Friends experiencing similar symptoms have gone through extensive elimination diets, carefully limiting and tracking their food intake to pinpoint the culprit of these digestive issues. Now food sensitivity tests are becoming increasingly common—not only in doctors’ offices, but in the form of at-home tests available at drugstores. Do they actually work?
According to the New York Times, there’s not a single consensus on what the definition of “food sensitivity” is, and although that’s the phrase used for marketing these tests, doctors and dieticians are more likely to refer to these as food intolerances or symptoms of irritable bowel syndrome. Neither of those are the same condition as a food allergy, which is when eating something causes a severe reaction within minutes, like vomiting, hives, shortness of breath, or life-threatening anaphylaxis. If you’re having symptoms of that magnitude, head straight to a doctor for an allergy test.
Food sensitivity can be the cause of symptoms like abdominal pain, bloating, or headaches—for example, a lactose intolerance can be classified as a food sensitivity and usually manifests as constipation, diarrhea, and bloating. None of these things are necessarily life-threatening, but are definitely an annoyance and can impact one’s quality of life.
Over-the-counter food sensitivity tests will typically ask for either a hair or blood sample to be mailed into a lab that delivers digital results several weeks later. As the New York Times explains, tests that use hair samples claim to measure the “bioresonance” of your hair, which is an unproven holistic technique that measures the energy wavelengths coming from your body. Tests that use blood measure how the size of your blood cells changes after exposure to food extracts. In both cases, the results usually include a list of foods that might be causing problems.
Many of the at-home tests say that after receiving your results, you should start an elimination diet to see exactly what is causing your issues. And according to experts who spoke with The New York Times, that elimination diet is the only part of the test that actually matters. Medical organizations in the U.S., Canada, and Europe have all spoken out against these tests because of a lack of evidence that they work. One doctor says that there’s nothing in your hair that would say anything about insensitivities to food, and blood tests are inconclusive because the way these substances interact in a test tube can be very different than how they interact in your body.
While taking an at-home food sensitivity test isn’t necessarily harmful, it can be a waste of time and money—tests can go for as much as $600 and typically aren’t covered by insurance. In some extreme cases, people might be provided with a long list of foods potentially causing problems and mistakenly take that as law, restricting foods unnecessarily and potentially developing disordered eating habits that leave them deprived of key nutrients in the process. Until there are more trials validating the results of these at-home tests, it’s best to avoid them altogether.
The best course of action to figure out what’s irritating your gut is a medically outlined elimination diet, which involves avoiding certain food groups and reintroducing them to your diet one by one to see how your body reacts. It’s a tedious process, but it’s one that might reveal that broccoli is what ails you, leaving you free to eat as much pizza as you want—maybe that’s not a typical outcome, but hey, a girl in her 30s can dream.