What is a Food Allergy?

A Brief Description of a Food Allergy

A food allergy occurs when the body's immune system overreacts to a food or food ingredient, mistakenly identifying the substance as a threat to the body and hence triggering a protective response.

The response takes the form of the production of excess mediators being released from the mast cells and reacting with the antigen in the apparently harmless food. In this case, even though there may be no bacteria or virus present, the antigen in the food fits the antibody, causing the mast cell to trigger and produce excess mediators, such as histamine.

The main triggers of food allergies are foods such as:

  • Peanuts and other nuts
  • Shellfish and fish
  • Wheat
  • Eggs
  • Soy
  • Cows milk

Food allergies can be severe, in some cases life threatening and usually occur shortly after eating the offending food.

Symptoms of an allergy can include a tingling, itchy mouth, swelling of the lips, face, tongue and throat, breathing difficulties, abdominal pain and vomiting. A severe allergic reaction, known as anaphylaxis requires emergency treatment and can result in constriction and tightening of the airways making breathing difficult, rapid pulse, dizziness and loss of consciousness and shock, with a severe drop in blood pressure.

Food allergies can sometimes be confused with food intolerance. There is however a clear definition between the two as an allergic reaction to food will produce an immune system response which can be proven via laboratory testing.

A food intolerance however does not involve the immune system, is less severe than an allergic reaction, and can present itself in different ways. Usually reactions to a food intolerance are slower than with an allergy and symptoms can be varied and irregular.

Learn how to build a strong immune defence here.