Food Allergy vs Food Intolerance

Before we deal in any length about how food allergies come about, it is necessary to establish what they really are. And how are they different from food intolerance which is far more common.

What is a food allergy?

A food allergy is a reaction from your immune system. In a food allergy, the immune system mistakenly identifies a specific food or a component of a food as a harmful substance. And it triggers certain cells to produce immunoglobulin E (IgE) antibodies to fight the culprit food or food component. So the next time you eat even the smallest amount of that food, the IgE antibodies sense it and signal your immune system to release histamine and other chemicals into your bloodstream. Signs and symptoms of a food allergy may include tingling in the mouth, hives, swelling of the lips, face, tongue and throat, wheezing or breathing difficulties, and dizziness or fainting, and at the very extreme, results in anaphylactic shock.

What is food intolerance?

Food allergies are more uncommon and only about 2% of adults and 6%of children have a true food allergy. Far more people have a food intolerance, unpleasant symptoms triggered by certain foods. Unlike a food allergy, a food intolerance doesn't involve the immune system. Lactose intolerance is one example of a food intolerance. People with lactose intolerance lack the enzyme lactase needed to digest milk sugar (lactose) in milk and other dairy foods. This inability to break down lactose during digestion may cause diarrhea, gas, bloating and abdominal pain.

The difference

It's important to distinguish food intolerance from food allergy. If you have a food allergy, eating even the tiniest amount of the food may trigger a serious allergic reaction. By contrast, if you have a food intolerance, you usually can eat small amounts of the food without a reaction.

[Source : Mayo Clinic]