If you are interested in the health and wellness world, you probably have heard people talking about food allergies and food sensitivities. You might be wondering what the differences are and how you can figure out what foods you may be reacting to. If this sounds like you, then this article is for you!
First let’s talk about some of the terms involved. There are actually four types of allergic reactions that can happen in the body, types 1 through 4. Type 1 is also known as an immediate hypersensitivity reaction, involving IgE antibodies and histamine. An example of this type of reaction is having an anaphylaxis reaction to a food, peanuts is one of the most common. Type 2 is also known as cytotoxic hypersensitivity reaction, involving IgG and IgM antibodies. Type 3 is an immune complex reaction. This is the type of allergic reaction that happens when people react to certain medications like penicillin. Lastly, Type 4 is a delayed hypersensitivity, involving a T cell reaction. An example of this is having contact dermatitis.
Other people have an autoimmune reaction to gluten, a molecule in wheat and other grains that makes it stretchy. This is called Celiac disease and is much more rare than food sensitivities (as indicated by the picture above this article). In Celiac disease a person’s immune system makes an antibody to an enzyme in the body called tissue transglutaminase. This is a more complex process than the above allergic reactions. In autoimmunity, a signal has become disrupted and the body starts making antibodies to certain parts of itself. We see this happen in all autoimmune diseases. The various antibodies depend on what system is being “attacked”. Another common example is Hashimoto’s thyroiditis, an autoimmune condition where the body makes antibodies to an enzyme in the thyroid endocrine system. Ironically, there is a big cross reaction that happens with gluten and the thyroid receptors in Hashimoto’s. Read more about that in our January newsletter here.
What many people know as getting tested for allergies, is the skin prick test. This is commonly done by an allergist. This can be helpful if the type of reaction experienced is that Type 1, IgE mediated allergic response. However, if the reaction being experienced is at the gut level with IgA or more of a systemic reaction with IgG, these allergic reactions will be missed on a skin test. IgA antibodies are made in secretions like tears, breastmilk, and all along the digestive tract. Take a moment to stop and think about the logic in testing the skin for a reaction that is happening in the gut. That is not to say that reactions in the gut couldn’t cause a topical skin response, but deeper reactions can be missed with doing this testing alone. So testing for IgG and IgA will catch more reactivity that may be happening.
These type 4, delayed sensitivity reactions can take 2-72 hours to notice a symptom. It is often very difficult to figure out the offending food when it was eaten 3 days ago. Additionally, many people do not rotate foods in their diet enough to be giving the immune system a rest. When people do an elimination diet, it allows the immune system to fully rest for 2-6 weeks. Then it becomes more obvious what reactions are happening with the reintroduction phase.
Often people have a few (commonly 1-3) major food sensitivities. The most common ones are dairy, gluten, eggs, soy, and corn. These are also the foods that are used in many food products and are often heavily genetically modified (GMO). So the good news is that eating a clean diet that is free from GMO foods and low on processed foods, can reduce inflammation and sometimes reactivity to these allergenic foods. Sometimes it is best to avoid a food altogether. The more that inflammation can be reduced, through dietary changes, supplements, and lifestyle habits; the less reactive the immune system will become. Patients are often surprised at how great they feel by uncovering this key piece of information.
At Amber Wellness Group, a food sensitivity test (IgG and IgA) is done through a simple blood draw. This can often uncover food reactions that might not be caught through an elimination diet alone. However, both choices can help identify what reactions may be happening. If an autoimmune reaction is suspected, the provider may suggest bloodwork or a stool sample to analyze these reactions further.