Food allergies and intolerances are on the rise. There are tons of theories to explain why this is happening, but I won’t even pretend to know the answer – because I don’t. But what I do know is that many people are being diagnosed based on allergy testing that may not be all that accurate.
There are a few standard tests used by health professionals that are known to be accurate. These include skin pricking, blood tests for IgE antibodies, food challenges (suspected foods are fed to you under medical supervision), and food elimination challenges (foods are eliminated and then reintroduced one at a time). To say for sure that you have an allergy, usually more than one of these tests will be done. Taken alone even these standard tests many not get it right.
What makes things even more complicated is the fact that there are also many tests used that do not have scientific evidence behind them. One of these tests is a blood test for IgG antibodies. This sounds legitimate, right? But there is actually no evidence that this test is accurate. In fact, IgG antibodies are thought to actually be a normal response in your body to food! So if an IgG antibody test comes back positive for wheat, for example, it’s probably because you’ve recently eaten wheat. But it doesn’t mean you’re allergic to it! Other alternative tests like hair analysis, muscle response tests, and pulse tests are also lacking any evidence to say they are useful.
Many people still use these tests though, which concerns me as a dietitian. Because these tests often tell people that they are “allergic” to foods when they didn’t even notice any symptoms to begin with, leading to unnecessary elimination of foods. And when eliminating foods, especially multiple foods or entire food groups, there is always risk of nutritional deficiencies. Plus, allergies are no fun (this is coming from someone with allergies). Why submit yourself to a life of restriction when you may not need to?
So if you have a suspected food allergy, your best bet is to make an appointment with an allergist for accurate testing. And for people with food allergies, especially young children, I strongly encourage seeing a Registered Dietitian for help selecting a safe, nutritionally adequate diet!
Note: If your allergy tests come back negative but are experiencing unpleasant symptoms, you may be intolerant to the food. A food intolerance is different from a food allergy because it is not immune based. If you’re interested in food intolerances, let me know and I’ll write a post about it!