Everyone has heard about someone with a severe peanut allergy in which they have to carry an epi pen in case there is exposure. This is one type of immune reaction. There are other types of immune reactions that occur to foods that pose risks to your health. While they don’t seem to be life threatening like a severe allergy; they are contributors to many chronic diseases. We are going to focus on food allergies and sensitivities. We will look at what they measure, and clinical implications for the tests. We will first focus on food allergies as this topic is more widely talked about.
When one looks at food allergies they are thinking of an immediate reaction that occurs after coming into contact with a trigger. This can include peanuts, seafood, or strawberries to name a few. The individual can notice symptoms from a scratchy throat up to anaphylactic shock in which swelling occurs resulting in respiratory distress. This is the most severe response and can be life threatening if not addressed in a timely manner. This looks at a reaction called a type 1 hypersensitivity mediated by an IgE response.
In the past few years this topic continues to grow, with a special focus being around gluten. We will save the topic of gluten sensitivity for another time where we will examine it in detail. First, it is important to realize there is a big difference between allergy and sensitivities. Each of these involve a different part of the immune system. As stated previously allergies are IgE mediated, whereas sensitivities are IgG and IgA with a focus on IgG. IgG is not responsible for an immediate response. It is important to understand that, because you may not have an immediate reaction to the food you eat. It may take several hours up to days to have symptoms. This also makes it tricky when you are doing elimination diets. If you don’t space out returning foods then you may feel bad, but you will not be able to isolate which food is giving you more problems.
Food Sensitivity Testing
Testing is becoming more common than it was in the past. There are those that look at changes to the immune cells when interacting with the protein from a food. While others look at the immune response in the form of IgG and IgA counts to specific proteins to determine the level of sensitivity present. It is important to understand also that food changes when it is heated. This is why some people can eat cooked onions but have gut complaints if they eat them raw.
When you receive the results it is important that you follow them. These are not merely suggestions, but are a reflection of your immune response. The greater response you have, the more inflammation that is present when you consume these. It is even more important that you follow the results if you have an autoimmune disease such as crohn’s, ulcerative colitis, or rheumatoid arthritis to name a few.
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Vojdani, A. (2015). The evolution of food immune reactivity testing: Why immunoglobulin G or immunoglobulin A antibody for food may not be reproducible from one lab to another. Alternative Therapies in Health and Medicine, 21 Suppl 1, 8.