Many terms are floating around for food reactions, and each refers to a specific response that is either mediated by the immune system or due to a missing enzyme. Let’s dive deeper into the different reactions and the testing that can be done to determine the cause.

Food Allergies

Food allergy reactions are probably one of the most well-understood reactions. We all know someone who has a peanut allergy or another food allergy (at least know someone who knows someone). The allergy reaction is obvious in how it pops up: hives, throat closing, itching, etc.

These reactions are mediated by a pathway in the immune system that ultimately ends up activating an antibody called IgE, and those activate mast cells which release histamine. Histamine is the molecule that causes hives, itching, and in the worst-case scenario, anaphylaxis. At its base function, histamine is a signaling molecule for the immune system. Sometimes, it just goes a little bit crazy.

Testing for food allergies is most commonly done via skin prick testing, but can also be done by a blood draw to measure levels of the IgE antibodies to different food substances.

Most importantly, treatment involves avoidance of the trigger but can be helped with antihistamines depending on the level of reaction.

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Food Intolerances

Food intolerances aren’t generally mediated by the immune system. Instead, the body lacks an enzyme necessary for breaking down that molecule. The most common intolerance is probably lactose intolerance. Reactions tend to be limited to digestive distress instead of causing symptoms that spread all over the body. So if people have food intolerances, they tend to have gas, bloating, and bowel movement changes.

Testing for food intolerances is pretty straightforward. You remove the food and see if that improves symptoms. People can also take the missing enzyme to help replace the enzyme that they’re missing. This can replace the enzymes and allow the breakdown of that molecule, meaning that it can be absorbed by the person’s body.

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Food Sensitivities

Food sensitivities are a group of reactions that don’t have one traditional way they pop up. I’ve had patients come in with skin concerns, lung issues, digestive upset, and many other symptoms! Most commonly, I see food sensitivities linked to eczema, but we also consider food sensitivities for patients who have digestive upset, autoimmune disorders, and many other conditions. These reactions create low-grade inflammation in the GI tract every time they’re eaten. And that inflammation can show up to 72 hours after eating the food. So tracking down the cause can be a bit tricky and may not be immediately after ingesting that food.

These reactions can be mediated by any arm of the immune system, which makes testing them tricky. The gold standard for testing for food sensitivities is an elimination and reintroduction diet. However, there is the option to do IgG antibody testing which can provide a starting point for patients to determine what is affecting their digestive system.

Treatment of food sensitivities involves removing the offending food for several months so the GI tract doesn’t experience as much inflammation and can more effectively recover and repair. Then, patients can attempt to re-introduce the foods to see if they can eat those foods again.

Photo by Sora Shimazaki: https://www.pexels.com/photo/woman-suffering-from-a-stomach-pain-5938358/

Final thoughts

Many people use these terms interchangeably every day (both practitioners and patients alike), and there’s nothing wrong with that. However, it’s good to know what symptoms you’re having and what might be causing them. This can help direct you to the right testing or the right treatment. Feel free to reach out to our providers to learn more about the testing available at SHEN.