Food Intolerance and Food Allergy

Food intolerance, food sensitivity, food allergy – the terms are sometimes used interchangeably, but they actually are very different conditions. While some symptoms of food allergy and food intolerance are similar, a true food allergy involves an immune system reaction and several organs in the body are affected. A food intolerance reaction involves the digestive system.(1)

Most physical reactions to foods are caused by a food intolerance, as opposed to a food allergy.(2) A food intolerance is the result of a person’s inability to break down a food, because of enzyme deficiencies, sensitivity to food additives or chemicals in the food that are naturally occurring. People with a food intolerance are often able to eat a small amount of the food they are sensitive to without a problem.(2)

There are several causes of food intolerance, including:

  • Absence of an enzyme needed to fully digest food – lactose intolerance is an example of this
  • Irritable bowel syndrome
  • Celiac disease
  • Sensitivity to food additives – for example, sulfites can trigger symptoms in some people(2)


An allergic reaction to a food involves the immune system. During a reaction, the immune system produces antibodies called Immunoglobulin (IgE). Food allergy symptoms almost always have a skin component (hives, swelling), and can also involve the stomach (nausea, pain, vomiting) and the respiratory system (wheezing, trouble breathing). Without immediate treatment, the serious allergic reaction anaphylaxis can be fatal.(3)

The American Academy of Allergy, Asthma & Immunology recommends that a person see an allergist if:

  • If you think you might have a food allergy
  • If you have limited your diet based on possible food allergy
  • For the best diagnosis, as well as treatment and avoidance measures for food allergy(1)


For allergy professionals, Xtract Solutions offers cloud-based Allergy Immunotherapy software, designed to organize the allergy practice, from initial testing through to successful completion of immunotherapy.

(1) American Academy of Allergy, Asthma & Immunology, Food Intolerance vs. Food Allergy, https://www.aaaai.org/

(2) Li, J., MD, PhD, Mayo Clinic, Food Allergy vs. Food Intolerance: What’s the Difference? https://www.mayoclinic.org/

(3) Lieberman, J. MD, Allergy and Asthma Network, Ask the Allergist: What’s the Difference Between Food Allergy and Food Sensitivity? https://allergyasthmanetwork.org/