Are food-sensitivity testing kits useful?
Allergic reactions to food happen when the immune system reacts to a substance that’s introduced into the body. During that exposure, the immune system makes antibodies to that substance. When the substance is consumed again in the future, the immune system quickly identifies it and creates more antibodies to fight it off—causing what we know as an allergic reaction. Allergic reactions may present as rashes, throat swelling, difficulty breathing or fainting, and require immediate help from a medical professional.
Food intolerances aren’t allergic reactions and don’t require immediate medical evaluation. However, because they can cause uncomfortable symptoms such as bloating, abdominal discomfort, nausea or loose stool/diarrhea, you may find it beneficial to be aware of any food sensitivities you may have. So, what’s the best way to get tested for a food sensitivity?
At-home food-sensitivity testing kits
These may be a tempting option due to cost and convenience, but they aren’t a reliable option for finding food sensitivities. Food-sensitivity testing kits claim to reveal specific food sensitivities by finding specific antibodies called IgG. IgG hasn’t been shown to reliably identify food allergies or food sensitivities.
An allergist—a medical professional who specializes in the immune system—can perform various blood tests and skin prick tests to identify specific antibodies called IgE. These antibodies indicate a response in the immune system, or an allergy, to a specific item. While this may be helpful for those with food allergies, food sensitivities or intolerances don’t mount an immune response, so this testing may not be helpful for individuals who have food intolerances.
Food sensitivities or intolerances aren’t allergic reactions. Individuals with food intolerances may find that certain foods or ingredients disagree with their digestive systems but will not have an allergic reaction to those foods. For example, some individuals with lactose intolerance can tolerate certain lactose-containing foods such as hard cheeses or yogurt.
If you suspect you may have a food sensitivity, the best first step is to keep a very detailed food diary of every single food and beverage consumed over the course of a few weeks. With this method, specific trigger foods may be identified so that you can avoid them. Make sure to include the time of day foods were consumed and the specific symptoms each food item caused. It can also be helpful to track the time until onset of symptoms.
You should be evaluated by your primary care provider once this food diary has been completed to see if symptoms necessitate further workup.
Tara Menon is a gastroenterologist at The Ohio State University Wexner Medical Center.