Into the Spotlight

Is It Food Allergy or Food Intolerance?

Contributed by Kathleen S. Williams, R.D., C.S.G.

Allergic foods in clockwise order: Peanuts, Blue Cheese, Grain, Egg

A food allergy occurs when a food you eat abnormally triggers your body's immune system. Sometimes even a very small amount of a food can trigger such a response. The body may respond to the food allergen with such symptoms as digestive problems, hives or impaired airway. In some cases, the reaction may be as extreme as to be life threatening, with a reaction called anaphylaxis. Anaphylaxis is a severe whole body reaction to an allergen.

Food allergies are often seen in children. Children who have food allergies may find that the food item is no longer an offense to their immune system as they grow older. A common food allergy for children is an allergy to soy.

Adult foods often associated with allergic reactions:

Mother and daughter cooking.

"Food intolerance" is different from a food allergy. Food intolerance is a reaction to a food that does not involve the body's immune system. While the reaction may feel as if it is a food allergy, if the immune system is not responding, it is food intolerance. Sometimes it is an additive to a food item that may trigger the intolerance symptoms. Some common intolerance in adults are:

  • Monosodium glutamate (MSG) is a flavor enhancer which, in large amounts, can cause such symptoms as flushing, headache and chest discomfort. MSG is found in prepared foods such as sauces, dressing, chips, and seasonings.
  • Sulfites - sulfites are naturally occurring in some foods, such as some wines, and used in food to increase crispness. Intolerance to sulfites can cause breathing problems for people with asthma.

Lactose Intolerance defines food intolerance to a sugar, lactase, found in milk and milk products. While uncommon in young children, it is more common in adults. The enzyme needed to break down the lactase declines as people age. When lactase is not broken down by the needed enzyme, the gut may respond with symptoms such as abdominal pain, bloating and diarrhea. Your health care provider can run some laboratory tests to determine if you have lactose intolerance.

Read More:

Food Allergies: Reducing the Risk (PDF)

Food allergy: Can it develop later in life?

Tips to Remember: Food Allergy


Updated/Reviewed: July 1, 2011