Spotlight on the Lab: Food Allergy and Sensitivity Testing

Many of my patients come to me initially for food allergy and hypersensitivity testing. However, they are often unclear as to how the test is taken, what it is testing for, and how it will help them feel better. In addition, there has been an increase in media attention to naturopathic approaches (also called “functional medicine” by MDs) to treating digestive, autoimmune, and other diseases and syndromes which are affected by diet.

Naturopathic doctors have been at the forefront of allergy and hypersensitivity testing for over 30 years, and our knowledge and expertise have helped thousands of people feel better through elimination or reduction of offending foods and substances. One thing we help people understand is the difference between a food allergy, a food hypersensitivity, and other forms of food intolerance.

Food allergies are anaphylactic-type reactions to foods, and are mediated by an immune molecule called IgE. These allergies can be life-threatening (in 1% of cases), causing difficulty breathing, rashes or eczema, sweating, vomiting, diarrhea, swelling and hives, and symptoms appear immediately after eating the offending food. We can test for total IgE, or for IgE reactions to a broad spectrum of foods, by taking a blood sample from the patient and extracting the serum for analysis. Unlike other kinds of testing, eating foods you may be allergic to is NOT recommended before testing for IgE. In addition, the type of testing we provide is good for assessing non-acute reactions, such as digestive distress or skin rashes, but is NOT recommended to find life-threatening acute reactions (that requires a referral to an allergist MD, as they have access to the appropriate tests). This test costs between $275 and $475, and includes both IgE and IgG testing, as well as an option to test IgA, an immune marker associated with damage to the gut lining.

Food hypersensitivities are controlled by another immune molecule: IgG. These molecules are specific to the offending food protein, and attach to it in the bloodstream, making an “antibody-antigen complex” and marking it for destruction by white blood cells. With repeated contact, these complexes build up and are deposited in tissues such as joints, the digestive system, the nervous system, skin and cause reactions like joint pain, bowel diseases, migraines, psoriasis and eczema and weight gain/bloating.
We test for this by taking a small amount of blood. These symptoms usually show up between 30 minutes and 72 hours of ingestion, so we encourage people taking this test to eat all the foods they would usually eat twice a week for 3 weeks before testing, including foods they are avoiding because they cause symptoms. Because the immune system removes these complexes over time, foods that are avoided will not usually be positive on the IgG test. IgG testing for 96 common foods costs 275$, with options to add additional foods for testing, or a vegetarian-only food panel.

Food intolerances are usually due to a lack of a given enzyme to break down a food. The most famous is lactose intolerance, which can be tested with a breath test. In BC, we can send you to Life Labs to have this tested for $75.

Celiac Disease (CD) is an immune response to the presence of gluten and gliadin, two related proteins found in grains such as wheat, rye, barley, resulting in severe inflammation and destruction of the gut mucosa and villi, problems with absorption and a host of digestive, neurological, ocular, joint and skin symptoms, and can be life-threatening. We can do testing for CD with a blood sample taken in-office, which tests for IgG and IgA reactions to gliadin, as well as anti-tissue transglutaminase, a test for an enzyme present in CD. Positive results lead to a referral for biopsy to confirm CD. This test costs $195.

Candida is a yeast normally present in low levels in the gut and associated tissues. Overuse of antibiotics, high sugar diets and stress can all lead to an overgrowth of candida and symptoms such as recurrent yeast or urinary tract infections, rashes, sugar cravings, bloat and other digestive problems, and brain fog. We can test for IgG, IgM, and IgA antibodies to candida with a blood test taken done in-office. This test costs $175.

Deciding which type of test is right for you requires an understanding of your symptoms and history. A qualified naturopathic doctor such as I, can take a good clinical history and recommend the appropriate test that will get you feeling better fast!

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