Food Allergies vs. Food Intolerances
A food allergy is an immune system response. It occurs when the body mistakes an ingredient in food -- usually a protein -- as harmful and creates a defense system (antibodies) to fight it. Allergy symptoms develop when the antibodies are battling the "invading" food. The most common food allergies are peanuts, tree nuts (such as walnuts, pecans and almonds), fish, and shellfish, milk, eggs, soy products, and wheat.
Food intolerance is a digestive system response rather than an immune system response. It occurs when something in a food irritates a person's digestive system or when a person is unable to properly digest or breakdown, the food. Intolerance to lactose, which is found in milk and other dairy products, is the most common food intolerance.
Symptoms of Food Allergy
Symptoms of a food allergy can range from mild to severe, and the amount of food necessary to trigger a reaction varies from person to person. Symptoms of food allergy may include:
• Rash or hives
• Stomach pain
• Itchy skin
• Shortness of breath
• Chest pain
• Swelling of the airways to the lungs
Symptoms of Food Intolerance
Symptoms of food intolerance include:
• Stomach pain
• Gas, cramps or bloating
• Irritability or nervousness
Food allergies arise from sensitivity to chemical compounds (proteins) in food. They develop after you are exposed to a food protein that your body thinks is harmful. The first time you eat the food containing the protein, your immune system responds by creating specific disease-fighting antibodies (called immunoglobulin E or IgE). When you eat the food again, it triggers the release of IgE antibodies and other chemicals, including histamine, in an effort to expel the protein "invader" from your body. Histamine is a powerful chemical that can affect the respiratory system, gastrointestinal tract, skin or cardiovascular system.
As a result of this response, allergy symptoms occur. The allergy symptoms you have depend on where in the body the histamine is released. If it is released in the ears, nose and throat, you may have an itchy nose and mouth, or trouble breathing or swallowing. If histamine is released in the skin, you may develop hives or a rash. If histamine is released in the gastrointestinal tract, you likely will develop stomach pains, cramps or diarrhea. Many people experience a combination of symptoms as the food is eaten and digested.
Food allergies often run in families, suggesting that the condition can be inherited.
Food Intolerance There are many factors that may contribute to food intolerance. In some cases, as with lactose intolerance, the person lacks the chemicals, called enzymes, necessary to properly digest certain proteins found in food. Also common are intolerances to some chemical ingredients added to food to provide colour, enhance taste and protect against the growth of bacteria. These ingredients include various dyes and monosodium glutamate (MSG), a flavor enhancer.
Difference between a Food Allergy and Intolerance
Food allergies can be triggered by even a small amount of the food and occur every time the food is consumed. People with food allergies are generally advised to avoid the offending foods completely. On the other hand, food intolerances often are dose related. Learn which foods in which amounts cause you to have symptoms and limit your intake to amounts you can handle. Sometimes omitting the food for a period of time and re introducing it at a later stage helps.