There are many terms used for adverse food reactions including food allergies, food sensitivities, and food intolerances that are often used interchangeably by the general public, and even among some clinicians, which maybe confusing. This is partly due to the fact that there are many pathways in the body through which food can trigger adverse reactions (IgE-mediated vs. non-IgE-mediated, immunological vs. non-immunological, etc) and these terms do not specify these specific pathways of mechanism.
What is Food Allergy?
The National Institute of Allergy and Infectious Diseases (NIAID) developed a clinical guideline for the diagnosis and management of Food Allergy in 2010 and defined food allergy as “an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food”[1].
The problem with this definition is that it includes both IgE-mediated reactions to food and some non-IgE-mediated reactions to food. The IgE-mediated food allergy (Type I hypersensitivity or immediate hypersensitivity) is what people commonly think of as food allergy where people can have a rapid onset life-threatening anaphylactic reaction, urticaria, and angioedema to triggers such as shellfish and nuts.
What is Food Intolerance?
Food intolerance is a non-immunologically mediated reaction to food due to lack of a digestive enzyme, such as lactose intolerance when a person is unable to digest lactose found in milk due to a lack of an enzyme called lactase. It’s a a digestive system response rather than an immune system response [2].
What is Food Sensitivity?
Food sensitivities are non-IgE-mediated food reactions and include delayed reactions mediated by IgG antibodies, immune complexes and cellular responses encompassing Type II, Type III, and Type IV hypersensitivities.
Type I: Reaction mediated by IgE antibodies (Anaphylactic)
Type II: Cytotoxic reaction mediated by IgG or IgM antibodies
Type III: Reaction mediated by immune complexes
Type IV: Delayed reaction mediated by cellular response [3]
Food sensitivities are the most prevalent out of the 3 categories (30-40% of the population), most complex, and are a common source of inflammation for many digestive complaints and chronic conditions such as IBS, IBD, depression, obesity, metabolic syndrome, GERD, migraine, fibromyalgia, arthritis, ADD/ADHD, and skin issues [4].
The complexity of identifying food sensitivities is due to the fact that symptoms can manifest many hours after ingestion, reactions could be dose dependent meaning a small amount of food may not lead to symptoms while ingestion of larger amounts may cause symptoms, and there are many pathways through which a reaction can be triggered.
Regardless of through which pathway the food sensitivity is triggered, one common feature of all food and food chemical sensitivities is that they all result in release of mediators such as cytokines, leukotrienes, prostaglandins from our white blood cells (neutrophils, monocytes, eosinophils, and lymphocytes) that cause inflammation in the body. This release of mediators can be tested through a blood test called MRT or Mediator Release Test, which will identify sensitivities to common food and food additives. Some clinicians use IgG food sensitivity test, which looks at one of the pathways, whereas the MRT test looks at culminative endpoint markers and thus identifies sensitivities to both foods and food chemicals arising from any of the pathways mentioned above.
It’s important to identify and remove your food sensitivities temporarily to 1) alleviate your symptoms, 2) halt the progression of chronic disease, and 3) to allow the body to heal, all the while working on addressing the root cause of why the food sensitivity developed in the first place. There are many reasons for why someone could develop food sensitivities including increased intestinal permeability, gut dysbiosis, food poisoning, infections, nutrient deficiencies, weakened digestive enzymes leading to incomplete indigestion of food, and use of medications that lower the stomach acid such as proton pump inhibitors.
If you would like to find out if you have a food sensitivity, please consult a naturopathic doctor.
References
1. Guidelines for the Diagnosis and Management of Food Allergy in
the United States. J Allergy Clin Immunol. 2010 December ; 126(6): 1105–1118. doi:10.1016/j.jaci.2010.10.008. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4241958/pdf/nihms247492.pdf
2. Food Problems: Is it an Allergy or Intolerance. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/10009-food-problems-is-it-an-allergy-or-intolerance
3. Marwa K, Kondamudi NP. Type IV Hypersensitivity Reaction. [Updated 2021 Apr 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK562228/
4. Understanding Diet-Induced Inflammation. Oxford Biomedical Technologies. https://www.nowleap.com/understanding-diet-induced-inflammation/
Author
Dr. Namuun Bat, ND is a licensed naturopathic doctor at Sacramento Naturopathic Medical Center and can be reached at (916) 446-2591.
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