It’s not just “bad” food that causes problems with digestion and absorption. any food, including “good” foods have the potential to be an allergen in the body. Food allergies are very common and very often overlooked. In fact, many medical professionals don’t look for food allergies because they fundamentally don’t believe in them. However, the evidence for food allergies is overwhelming and most private labs offer food allergy testing.

There are 4 main categories of food allergies to become aware of so you can identify them. When most people, including many medical professionals hear the word “allergy” they think of the typical symptoms like skin rash, hives, swollen throat, itchy watery eyes, and nasal discharge. However, this really only reflects one type of allergy, the IgE-mediated Immediate Sensitivity reaction. The chart below describes the differences between the 4 categories of food allergies you should distinguish between.

IgE-Mediated Immediate Sensitivity

IgG-Mediated Delayed Sensitivity

Within minutes after exposure

2-48 hours after exposure

Most likely 30min to 2 hours after exposure

Most likely within minutes after exposure

Blood draw for IgG levels

Electrodermal testing

IgE and histamine release from mast cells

IgG released from white blood cells

Deficiency of an enzyme to break down the food

IgE-mediated immediate sensitivity allergies occur when a protein triggers the release of histamine from de-granulated mast cells. The symptoms usually occur within minutes and are usually relatively severe and sometimes cause anaphylaxis. This type of allergy is most commonly induced by nuts, peanuts, shellfish, citrus, and environmental allergens like pollen, dander, and mold. IgE-mediated allergies are relatively uncommon for most other foods. The best way to test for IgE-mediated allergies is through skin prick testing. Anti-histamines provide relief for this type of allergy.

IgG-mediated delayed sensitivity allergies occur when a protein triggers the release of immunoglobulin G (IgG), an inflammatory product from white blood cells in the digestive tract. The symptoms usually occur anywhere from 2 to 48 hours after exposure and are of a more chronic and inflammatory nature. Common signs and symptoms include indigestion, gas, bloating, cramping, eczema, psoriasis, headaches, physical fatigue, mental fatigue, and edema. Anti-histamines do not improve these symptoms because histamine production is not involved. The best way to test for IgG-mediated allergies is to examine a blood sample for immunoglobulin G production from the white blood cell population.

Food intolerances are not a true allergy because they do not involve an immune-mediated response. Food intolerances occur when the body lacks an enzyme to break down certain food molecules. The most well known example is lactose intolerance where the body is deficient the enzyme lactose. therefore, whenever dairy products are consumed lactose is not broken down and causes digestive upset. Enzyme deficiencies can occur for almost any food and are not actually a true allergy but nonetheless cause digestive symptoms.

like food intolerances, food sensitivities are technically not a true allergy because there is no known measurable immune system response. In fact, we understand very little about the causes and mechanisms of food sensitivities. The best way to test for food sensitivity is through an elimination diet and ruling out IgE allergy, IgG allergy, and food intolerance. The treatment for food sensitivity is elimination or rotation diet.

In next week’s column we will investigate the physical causes of poor digestion. To learn more about natural treatments for digestion or to schedule a consultation contact Dr. Barlow at 250-860-8855.