Adverse food reactions—allergies or intolerances—often play a role in arthritis, fibromyalgia, chronic fatigue, migraines, IBS, colitis, Crohn’s disease, autism, multiple sclerosis, acne, eczema, rashes, seizures, interstitial cystitis, hyperactivity, learning difficulties, ADD, sleep difficulties, depression, anxiety and many other disorders.
Although food may be a significant factor in your health challenges, you may never realize it and your doctor may not tell you either. You may continue to suffer year after year without knowing that dietary changes could reduce or completely eliminate your symptoms.
Many different forms of food sensitivity
Although there are many different forms of food sensitivity, traditional allergists focus only upon classic IgE-meditated food allergy. These are the immediate onset allergies that trigger anaphylaxis, allergic asthma, urticaria, angioedema, allergic rhinitis, some types of drug reactions, and atopic dermatitis—although some of these conditions can be caused by non-IgE mechanisms as well. IgE meditated allergies affect just a small segment of the food reactive population—only the tip of the iceberg. A visit to a regular allergist’s office may leave you without any solutions whatsoever to your food induced symptoms.
There are many different types of food sensitivity. According to Janice Vickerstaff-Joneja, author of Dealing with Food Allergies, food sensitivity can be broadly divided into two major categories:
- Food allergies are immune-mediated reactions to a food. Within this category, the word “allergy” is generally reserved for the classic IgE meditated allergies described above. Other forms of adverse immune-related reactions like IgG and cytotoxic responses are referred to as “immune-meditated” responses.
- Food intolerances are non-immunological adverse reactions to a food or food additive. These include intolerance to lactose, tyramine, histamine, sulfites, MSG (free glutamate), artificial colors and preservatives, oxalates, benzoates, and other naturally occurring substances in foods.
These are two distinct and non-interchangeable terms with precise definitions, whereas the term “food sensitivity” may be applied to either.
Alternative approaches to identifying food sensitivities
If you suspect that you are your children might have an IgE mediated allergy, it is important to be properly evaluated by an allergist since these can be life-threatening. However, as you now know, most food sensitivities are not IgE mediated. While IgE mediated allergies are well understood, many other types of food sensitivity are not. This may be why allopathic doctors exclude the use of other forms of food sensitivity testing from their practice.
Fortunately, alternative testing methods are routinely used by physicians who practice naturopathy and integrative medicine as well as physicians and allergists who specialize in environmental medicine. Many licensed nutritionists are also at the cutting edge of this science. Given the vast array of causes for food sensitivities, no one test or method is adequate for detecting them all. Ferreting out food sensitivies among all the possible causes is not necessarily easy and requires determination, expertise, and skilled detective work.
Following is information on blood tests used to assess IgE, IgG, and IgA immune-mediated reactions only. They don’t assess for food intolerances as defined in the first part of this article nor do they assess cytotoxic reactions.
There is debate about the efficacy of blood testing for food sensitivity since it does not show 100% reliability. However, standard skin prick tests are also not 100% reliable, as is the case with most medical tests, and they only indicate IgE reactions. Although blood tests for food sensitivity may have some false negatives or positives, they can provide invaluable guidance when the results are seen within this framework. They have the added advantage of providing quick results. On the downside, alternative testing methods are not always covered by insurance.
Many allergists recommend a supervised elimination diet as the gold-standard for diagnosing food sensitivity. These require strong discipline over an extended period of time, which is not necessarily practical for everyone. Allergists view bood tests as indicators, and generally recommend confirming the results with follow-up elimination and challenge trials.
Despite the differences of opinion and approach, many alternative physicians successfully use serum Antibody Assessment (ELISA) for testing IgE, IgG, and/or IgA reactions to food and inhalants. Several friends have reported positive outcomes using these alternative antibody assessments and this approach has proven effective for me as well.
What are IgG immune-mediated food responses?
IgE mediated allergies have been explained above. So what are IgG immune-mediated food responses? U.S. BioTek Laboratories explains IgG mediated food sensitivity in this way:
“IgG antibodies represent the most prevalent class found in the blood. It is produced after reimmunization, or secondary response to antigen. It is the primary mediator of the memory immune response. Often involved in Type III delayed hypersensitivity reactions, IgG forms an immune complex with the allergen. This antibody/antigen complex activates complement (a group of small proteins found circulating in the blood stream that are involved in the release of inflammatory mediators), and enhances phagocytosis by opsonization. The inflammatory process is gradual and may take anywhere from several hours to several days, which is why this type of reaction is termed, delayed. Although immune cells called macrophages dispose of these immune complexes immediately, they only have a finite capacity to do so. Excess antigen may saturate the macrophages capacity resulting in the prolonged circulation of complexes and their deposition into the body tissues. Depending on which tissues are involved, it is thought that these complexes may be implicated in many different conditions/symptoms.”
Information about IgA immune-mediated reactions is available at the BioTek web site.
Taking the ELISA test
Labs typically offer a choice of panels that might include a general food panel, a vegetarian food panel, an Asian food panel (select labs), and an inhalant panel. Food panels usually test for 90 plus foods. In consultation with your physician, you are able to select IgE, IgG testing or both and some labs also offer IgA testing. A blood sample is taken according to specific instructions and sent to the lab for evaluation. Your doctor receives your test results about two weeks later.
Following is an image of one part of a sample test report for all three assessment panels (Ige, IgG, and IgA) combined together. The length of the bar indicates the degree of reaction to each food.
Your doctor will evaluate your results and make appropriate recommendations, which may include eliminating highly reactive foods and rotating others or eliminating all reactive foods for a period and then moving over to rotation. I highly recommend working with a qualified physician or nutritionist who is well versed in interpreting these particular tests. There are subtleties that can be missed by someone who is not familiar with food sensitivity or these tests. Even low scores can be indicative if you are familiar with patterns that may occur on the tests.
IgE and IgG Antibody Assessment (ELISA) testing is available from U. S. BioTek Lab, Genova Diagnostics (USA and International), Great Plains Laboratory and other innovative testing laboratories. The tests can be ordered through any doctor, but most standard physicians and allergists will scoff at the idea. My former allergist warmed me not to order any of those “alternative tests from California.” I’m so glad I didn’t listen to him or I might still be lost in an unending maze of unwellness. I can assure you that not one of these labs is located in California!
Other forms of food sensitivity testing include:
- A supervised elimination diet conducted by a nutritionist
- Conducting your own elimination diet using one of the published books on the topic like The Allergy Exclusion Diet by Jill Carter and Alison Edwards.
- Cytotoxic and mediator release testing (The Alcat; Mediator Release Testing (Signet Lab); FACTest, Food Antigen Cellular Test (Genova International). Some forms of testing may also represent IgG reactions.
Dr. Lewey, a board certified gastroenterologist, highly recommends the Meditator Release Testing when IgE allergies are not the case. This test is available in both the U.S. and Europe, but not in some locations like Hawai’i.
I suspect the effectiveness of a particular type of test will vary depending upon the precise mechanism behind an individual’s sensitivity. In addition, results may be less reliable if you have a limited diet, but may still show some basic trends. It can be difficult to decide which type of test to take. Therefore, it’s important to research the options thoroughly and see which tests seem to best fit your profile. Friends have reported good results with the ELISA IgG Antibody testing, the Mediator Release Testing, and the Alcat.
Some forms of food sensitivity testing are very expensive so shop around. The BioTek tests are the most reasonably priced that I’ve found, but your choices will also depend upon which tests your doctor prefers. And remember, these tests will only reveal immune-mediated responses. Your food sensitivities could be determined by entirely different mechanisms and this type of testing may have less relevance for you. Food intolerances (lactose, benzoates, histamine, tyramine, oxalates, and so on) are an entirely different ball game.
Do you have one or more food sensitivities? How did you discover them?
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