There’s an increasing prevalence of food allergies among both adults and children in the U.S. and worldwide. Recent reports about this might have you on the alert—especially if you’ve ever experienced any unpleasant symptoms after eating. And I get it, the prospect of having a food allergy can be scary! If you suspect you or your child may have a food allergy, there are a couple of options. You can schedule an appointment with the allergy doctor. If you don’t want to wait that long, however, there’s a growing number of easy and reasonably priced at-home tests. But before you purchase one, you should know what to expect.
I think I have a food allergy…
Generally, people report that they have food allergy symptoms at a higher rate than experts estimate. That doesn’t mean you don’t have any symptoms, but you may not have a true food allergy. It’s important to understand the different types of reactions that people have to foods.
- A true food allergy is a reaction that involves the immune system. It occurs when the body mounts an antibody defense against a substance that it considers an invader. In the case of food allergies, this substance is usually a specific protein. In the US, about 32 million people have true food allergies. They suffer with everything from hives to headaches and wheezing to vomiting— and food allergies can even be life-threatening! There are roughly 170 different foods that cause allergic reactions, but very few cause the vast majority of serious ones. This group includes peanuts, tree nuts, wheat, crustacean shellfish, fish, eggs, milk, sesame, and soybeans.
- A food intolerance is a more common food-related reaction than a true allergy. This usually occurs in the digestive system because the body cannot process certain foods or ingredients. Of course nobody likes the tummy troubles and fatigue that are typically associated with a food intolerance, but at least these reactions aren’t serious. It’s estimated that up to 20% of the world’s population may have a food intolerance. The percentage of people with true food allergies is much lower, depending on age.
- Food sensitivity is a generic term that many use interchangeably with food intolerance. Gluten, for one, is a food component that often elicits sensitivities or intolerances. (Some people have an intolerance to gluten even if they don’t have full-blown celiac disease.) Others include caffeine, lactose in dairy products, histamines in fermented foods, cured meat, dried and citrus fruits, avocado, and sulfites in beer, cider, and wine. Sensitivities can include oral symptoms (like itchiness in the mouth or throat), runny nose, reflux, and gas.
How do at-home allergy tests work?
Many at-home tests require you to prick your finger and send in a blood sample. Your sample is then analyzed for antibodies to a range of allergens, depending on what type of kit you purchased. There are many types, covering everything from environmental allergens, like ragweed, to stinging insects to pet allergens. Some test kits also look at food allergens.
When the test shows reactivity from immunoglobulin E (IgE) to a specific allergen, it’s possible you are allergic. A sensitivity, which doesn’t cause an immune response, is suggested by reactivity of a different antibody called IgG. But this is highly debatable (read on).
Some testing kits have you send in a hair sample for “bioresonance” analysis. Studying hair for information about food allergens is not based on any science. Avoid dealing with any company that uses hair samples (even for your pet—a marketing ploy that some companies use).
Are at-home food allergy testing kits reliable?
In general, food allergies are not diagnosed simply through a blood test (or even a skin test). An allergist or immunologist should also evaluate you clinically in order to diagnose an allergy. For example, along with the antibody test, an allergist will:
- Ask you about specific symptoms and timing of the symptoms
- Conduct a physical exam
- Inquire about the exact foods and amount consumed
- Perhaps even do skin prick testing or an oral challenge
It’s also important to know that testing IgG antibodies is not an approved way to identify a food sensitivity. Current scientific thinking is that the presence of IgG antibodies is a normal response to eating a particular food. Also, IgG antibodies are not equivalent to IgE antibodies, which are used to diagnose allergies.
Are you curious about whether or not you’re allergic or sensitive to a particular food? If so, an at-home test kit can provide interesting results that might lead you to schedule a doctor’s appointment. But just having test results isn’t the whole answer. In fact, don’t take those results as proof of anything. And don’t avoid entire food groups or specific nutritious foods because of them—this could be dangerous to your health!
My advice: Don’t waste your money on a questionable at-home test kit. Instead, find a board-certified allergist (preferably with expertise in food allergies) to give you an accurate diagnosis.