Adverse Food Reaction Naming

Stop offering broad food allergy panels and food IgG tests

If you are a pediatrician, family practice doctor, naturopath, or chiropractor, I beg of you to stop ordering broad food allergy panels and also food IgG tests. Please. It is well-known that many are getting their “education” online from social media—whether it is credible or not. As I watch many promote their pages, I see many with proclaimed severe food allergies and often will advertise how they live with 20+, 30+, and possibly even 40+ food allergies. I have actually contacted a few in an effort to help them since I have treated thousands of patients with food allergies. For the few that have responded, I have discovered an interesting thing—they actually don’t have that many true allergies. They have a variety of adverse reactions to foods, but with careful history, it is clear that it is not all allergy. However, they have had “broad panels of food allergy and food sensitivity testing” done. Their doctors have fallen to the marketing of the companies making money from the tests and ordered them. 

‍

The reality is with these patients (and many others) is they have a mix of several different kinds of adverse reactions to foods, but not all are allergies. Some patients have just one type and others have another type. Why does this matter? Let me use an analogy. What if every patient who had dyslexia or ADHD was lumped into the category being on the spectrum of autism? How effective would the treatment plans be? That is very similar to labeling patients with food intolerances or sensitivities as being food allergic. They aren’t the same. The risks aren’t the same. Testing is not the same. Interpretation of tests are not the same. Treatment and approach certainly are not the same. The ramifications on someone’s life, though, can be massive and often detrimental when we are not right or specific. It is important that patients avoid foods that they absolutely need to avoid, but unnecessarily avoiding foods can be detrimental on many levels. It is critical we get it right. If you do not know what you do not know or are unfamiliar with the nuances of the various adverse reactions to foods, then it is credible and admirable to refer to those who do. Please, do not test prior to doing that, just refer them. 

‍

Let’s dive into this and let me clarify the controversy and myths a bit more. What are the critical differences between food allergies, food sensitivities, and food intolerances? There are hundreds of articles defining these, but I want to give you a simple way of thinking about them. Of note, there are more ways than these 3 that food can affect the body such as celiac disease, small intestinal bacterial overgrowth (SIBO), or food protein induced enterocolitis (FPIES), but for the purpose of this article I am addressing these three broad categories. 

‍

Food allergies

‍True food allergy is an immune-mediated response that usually occurs quickly and is reproducible and can occur with any amount of exposure to foods. When the immune system is activated, it signals a cascade of events mediated primarily through an antibody called IgE and the subsequent release of many chemicals including histamine, tryptase, and other inflammatory proteins and cells that yield the classic allergy symptoms that can affect multiple systems including the gastrointestinal tract (GI), respiratory tract, cardiovascular system, and skin. This can potentially be life-threatening and extreme caution needs to be exercised with strict food avoidance. 

‍

We can detect food specific IgE in the blood or on a skin test. This provides some evidence of support of what food allergies one may have. However, it is not a perfect test and not completely diagnostic. There can be false positives and false negatives. The test must be interpreted by someone who understands the nuances of the test and can explain the results in the context of that patient. All too often these tests are done, and patients are often told to unnecessarily avoid foods they may not truly be allergic to, thus creating a tremendous burden. The lesson goes back to medical school 101, if you don’t know what you don’t know and can’t interpret a test, don’t order it in the first place. Rather, refer to someone who can. There are some newer emerging tests such as basophil activation tests (BAT) that can be done in select centers in the United States. 

‍

Food intolerances

Enzyme deficiency, nervous system, exogenous histamine. Symptoms are located within the GI tract such as nausea, vomiting, bloating, gas, and diarrhea. It is most likely dose-related. This is non-life-threatening, but may make the patient feel…crappy.  

‍

Food sensitivity

This is where foods may cause gut inflammation. These patients will often come in with abdominal pain or vague constitutional symptoms and state they, “want a broad panel of tests done to find their hidden or unknown food allergies.” The symptoms can be immediate or delayed occurring hours to days after ingested food. It is primarily symptoms in the GI tract similar to food intolerances, but they may even cause gut inflammation (not mediated through IgE), that leads to the common symptoms of gas, bloating, diarrhea, constipation, brain fog, joint pain, or fatigue. These symptoms can be inconsistent with eating and inconsistent with the same foods. It is difficult because symptoms may also be delayed or chronic. This is a very common occurrence for which people are desperately seeking answers. To address this need there was a concept developed years ago that perhaps patients were experiencing a different kind of immune response to the food by other antibodies besides IgE. Food specific IgG was evaluated, and it was found that people indeed do make food specific antibodies specifically IgG. It was postulated that this is what accounted for the food sensitivities or “delayed food allergy.” Makes sense, right? People are having food issues, they may not be making IgE, but they are making IgG which is part of an immune response, and that, therefore, is the missing piece! Except it isn’t. But this is the hope that is sold so creatively to patients desperately seeking it. 

‍

Many companies and doctors who sell these tests producing tests claim this occurs because the body produces an antibody called IgG that may not trigger the immediate allergic reaction, rather a more delayed reaction for “hidden” or “low-level” food allergies, sensitivities, or intolerances. There is usually a spin that conventional doctors don’t usually check this test implying they know better. So, they focus the marketing on the point that a food specific immune response is taking place. However, there is a major part that is omitted or ignored: not all immune responses aren’t necessarily bad. We need an immune response to develop tolerance and insensitivity. The presence of food specific IgG has yet to be proven a bad thing. I have not seen a study validating this test or shown reproducibility that correlates clinically with the patient’s history. In fact, IgG to food exist in the body under normal conditions and is likely more of a measure of what is in the diet. Further, when allergists treat patient’s legitimate food allergies with a form of immunotherapy (oral or sublingual), IgG to those foods will increase and demonstrates tolerance—not intolerance or sensitivity. I have yet to see valid studies that show IgG causes the negative inflammation that is claimed. Even more problematic is when the references they cite are explored they are often from magazine articles, “their own research,” unreputable journals, from animal studies, or are sorely out of date. Why do they do this? Because most people may look to see if there are references, but they won’t look beyond at the actual reference. They will trust the phrase, “Research shows…” Here are some take-home questions to ask ourselves when we see the phrase, “research shows."

• What research? Was it actually in humans or just animals? How many studies? Were they legitimate and validated studies? 
• What were the research methods? 
• Were there conflicts of interest? 
• Who funded it? 
• Does the research show what they are actually claiming? Make sure you connect the dots. 
• Have the results been reproduced?
• Does the “reputable doctor” advertising the test benefit from others ordering it? 
• If there is something “specially formulated” that nobody else knows about, why does nobody else know about it?
• What do other experts in the field think of the studies, tests, or treatment?