Approximately one in 25 people suffers from a food allergy. They are slightly more common in young children and in people who have a family history of them. Most food allergies develop early in life, and many are outgrown.

Food allergies occur when your body's immune system reacts to a substance in a food, usually a protein, your body sees as harmful. This sets off a chain reaction within your body. Symptoms can occur within minutes and can be mild – such as a runny nose or itchy eyes to severe and even life-threatening.

A food intolerance is not the same as a food allergy. An intolerance occurs when your body is unable to digest a certain component of a food, such as lactose, a sugar found in milk; monosodium glutamate; or sulfites, a preservative. Though symptoms of intolerance may be unpleasant, including abdominal cramping or diarrhea, they are not life-threatening.

Types of Food Allergies

More than 160 foods are known to cause food allergies. However, eight foods account for 90 percent of all food-allergic reactions:

• Milk
• Egg
• Peanuts
• Tree nuts (walnuts, cashews)
• Fish (pollock, salmon, cod, tuna, snapper, eel, and tilapia)
• Shellfish
• Soy
• Wheat