Food intolerance tests

I am increasingly confronted with people who, when ordering a menu, write that they should not eat a number of common products - usually dairy products, eggs (or egg white), bananas and gluten - containing products - respectively, practically all cereals. Going into it, it is usually revealed that an IgG4 food intolerance test has been performed and the person is now convinced that these "bad" products are to blame for all his health problems, that it is they who are causing them.

A lot of research has been done on this topic and the conclusion is one - IgG4 food intolerance tests are absolutely not suitable for detecting food-related problems, because antibodies (IgG4 is an abbreviation "immunoglobulin G4”) Does not constitute a diagnosis. In addition, blindly following the test results is considered harmful, as it contributes to the elimination of healthy and necessary products for the body - and if the body does not receive all the necessary nutrients, real health problems may start, rather than imagined.

People who are unable to find an explanation for their symptoms often choose the IgG4 test, which they think is the best and fastest method of diagnosis, because the tests are quick, easy and seem to give a clear answer to unclear questions. The test results are surprisingly clear - the fault of several products is to blame! And it doesn't matter that almost the same products as the "bad ones" are shown to almost all testers -. And the worst - this test performers confuse the concepts of allergy and intolerance thereby facilitating the further dissemination of misleading information.

What is an allergy and what is product intolerance.

To begin with, there are two types food allergies - self-invented (eg after an IgG4 test) and real - when exposure to an allergen causes extreme discomfort and can even be fatal. An allergic reaction usually occurs immediately or within a few hours of eating the allergen-containing product.

Manifestations of food allergy

• Skin, mucous membranes - hives, angioedema or Quincke's swelling, redness, rash, itching, runny nose, runny nose, sneezing, itching, redness of the eyes, tearing;
• Gastrointestinal tract - abdominal pain, nausea, vomiting, diarrhea, blood and / or mucus in the stools, poor weight dynamics;
• Breathing system - cough, wheezing, difficulty breathing, tightness in the chest, hoarseness;
• Cardiovascular system - dizziness, fainting;
• Systemic reactions or anaphylaxis.

Several methods have been developed to diagnose allergies, but they have nothing in common with IgG4 tests. The doctor will usually ask you at the beginning about the use of the products, about the onset and disappearance of symptoms, about other illnesses, about the medicines you are taking, and so on. If this information does not provide the doctor with sufficient information about the causes of the symptoms, a physical examination will be carried out to assess the signs and severity of the allergic reaction. Thirdly, tests are being carried out. These may be a serum IgE test and / or a skin prick test, or an atopy application test where a specific allergen is applied to the skin and then a reaction is observed. All of these tests indicate only hypersensitivity to the specific allergen. In order to confirm or rule out the presumption that a particular food is causing allergies, it is necessary to continue with the exclusion diet and the food provocation test, which is considered the 'gold standard' in the diagnosis of food allergies. In this case, the allergen in question is removed from the diet for two to six weeks, after which it is restarted to monitor for symptoms. Unfortunately, there is no miracle test and the diagnosis of allergies should be made by an allergist, not by yourself.

IgG4 food intolerance tests

IgG4 is "immunoglobulin G4". Simply put, immunoglobulins, also called antibodies, are proteins that circulate in the blood and bind substances that the body recognizes as foreign and useless. By taking blood samples and exposing them to different foods, it is determined how these immunoglobulins G react to each product. If they are formed too much, intolerance of the products is detected.

The testers present the test results beautifully and offer additional advice from nutritionists and ready-made recipes, of course, with the idea that all products that were shown as "bad" in the test should be removed from the menu.

The belief in the test is very high because its mechanism is scientifically justified, but does all this mean that the test is effective, if only for the prevention of allergies?

For example, the European Academy of Allergy and Clinical Immunology recognizes that the IgG4 test does not show food intolerance, but simply the body's physiological response to food intake. IgG4 antibodies are produced in the body as a normal physiological response to food. They are detectable both in patients with allergic diseases and in healthy individuals. Antibodies are also observed when a product is used. Their levels often decrease when the product is stopped, but increase when used again. These diet-specific IgG4 antibodies do not indicate food allergies or intolerances.

Leading experts in the industry agree that the IgG4 test has other good applications, but it is absolutely unsuitable for diagnosing food-related problems, as the presence of antibodies does not constitute a diagnosis.

Repeated studies have shown that the IgG4 test is meaningless because, for example, it does not show milk intolerance, although it is clear from the use of milk that it causes indigestion in a particular person. Respectively, the test may show intolerance to products that are not actually present and vice versa.

Confidence in the IgG4 test is greatly enhanced by the fact that the test usually shows intolerance to milk, gluten, strawberries, bananas, eggs, and for many people, milk does cause indigestion, which is a fact. The man gives up milk, and - the problem is solved! The same is true of sweet fruits, which tend to cause bloating or bloating asymptomatic celiac disease a patient who, by excluding gluten, naturally begins to feel better.

But is it really necessary to say that "the sky is blue and the grass is green" to carry out useless tests and monitor their results by deliberately depriving the body of the nutrients it needs and, consequently, risking serious health problems in the future?

Sources:

https://sciencebasedmedicine.org/igg-food-intolerance-tests-what-does-the-science-say/

https://pubmed.ncbi.nlm.nih.gov/15864086/

https://pubmed.ncbi.nlm.nih.gov/21109748/

https://www.aaaai.org/Aaaai/media/MediaLibrary/PDF%20Documents/Practice%20and%20Parameters/EACCI-IgG4-2010.pdf

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1398-9995.2004.00495.x