The Connection between Food Allergies and the Immune System Response

by Kelley Lindberg


This week, I'm happy to host guest blogger Valerie Johnston, a health and fitness writer for Healthline.com. Her article examines the immune system's role in food allergy reactions, as well as the difference between a food intolerance and a true food allergy. Thanks, Valerie!

People who are genetically predisposed to have food allergies will not experience an allergic reaction until they are exposed to the food they are allergic to. In other words, the tendency to develop food allergies is already inherent, and the allergies then develop upon exposure to the allergen.

The body of a person who is genetically predisposed to allergies will produce a type of protein called immunoglobulin E (IgE) after being exposed to the specific food that they are allergic to. When the food is consumed, the body’s immune system is triggered to produce specific types of IgE in larger quantities than normal. After IgE is released, it attaches to the mast cells of the body. Your body’s mast cells occur in all of the tissues of the body, but are more commonly found in areas of the body that are associated with allergic reactions, including the skin, gastrointestinal tract, throat, and lungs.

In most cases, a person with food allergies will not experience symptoms until the second time they are exposed to the food allergen. This is because, after the IgE attaches to the body’s mast cells after the first exposure to a food allergen, they are now prepared to combat any foods that the body is allergic to the second time the food is consumed. When the allergen is consumed, the IgE on the mast cells triggers the release of chemicals known as histamines. It is these chemicals that cause a variety of food allergy symptoms.

For example, many people with food allergies have difficulty swallowing or breathing when they consume the foods they are allergic to. This is because the mast cells in the throat and mouth release histamine, which produces these symptoms. Histamine can be released wherever mast cells are located, including the throat, ears, nose, and gastrointestinal tract.

Food Allergy Vs. Food Intolerance

Most people who have food sensitivities (food intolerances) will say that they have a food allergy. It is very important to distinguish between these two problems, since food allergies can have life-threatening consequences and are related to the body’s immune system response.

As described above, a food allergy is a response to a food allergen by your immune system. In most cases, the body is responding to a specific protein in a type of food. Histamine antibodies are produced to fight against a specific protein that the body mistakes as harmful. Common food allergies include, but are not limited to, dairy, peanuts, tree nuts, shellfish, wheat, and soy products.

Symptoms of food allergies include:

• Nausea
• Hives or a rash
• Itchy skin
• Abdominal pain
• Chest pain
• Difficulty swallowing or breathing
• Anaphylaxis

Food intolerance is not an immune system response. Instead, a food tolerance is a response made by the digestive system. Some people have difficulty digesting certain types of foods, such as lactose (dairy intolerance).

Symptoms of food intolerances include:

• Nausea
• Vomiting
• Bloating, cramps, or gas
• Heartburn
• Headaches
• Diarrhea
• Constipation
• Irritability

While a person with a food allergy and a person with a food intolerance may share a few similar symptoms, the symptoms of a food allergy are usually a lot more severe and can even lead to death if the condition is not diagnosed properly. A proper diagnosis from your doctor or allergy specialist will allow you to prevent symptoms whether you have an allergy or intolerance to certain types of food.

Valerie Johnston is a health and fitness writer located in East Texas. With ambitions of one day running a marathon, writing for Healthline.com ensures she keeps up-to-date on all of the latest health and fitness news.