About 1-5% of the total population have food allergies. You have a food allergy when your immune system is involved in the reaction to the food. Only your doctor can diagnose whether you have a food allergy as you may react to foods without being allergic.
More than 120 foods may cause food allergies. The foods that most commonly cause serious allergic reactions on a worldwide basis are: milk, egg, peanut, tree nuts followed by cereals (mainly wheat), soybeans, fish, and shellfish. Most allergic reactions among children are due to a limited number of foods, namely egg, peanut, milk, and tree nuts. Egg and milk allergy are often outgrown during the first years of life. Fruits, vegetables, tree nuts and peanuts are responsible for most allergic reactions to foods among adults.
People with pollen or latex allergy may often experience allergic symptoms when they eat certain fruits, vegetables or nuts. This cross-reactivity occurs because pollen and latex contain proteins that are similar to proteins in food, and the immune system may react to both. In fact, up to 70% of food allergies are related to pollen allergy. As a general rule, processing of a food does not alter the ability of the food to induce allergic symptoms. However, most people with a pollen allergy can better tolerate the cross-reacting foods when they have been cooked, baked, or roasted.
Symptoms of food allergies vary between different people, although a person will tend to have the same reactions each time the allergenic food is consumed. The symptoms of food allergies range from mild discomfort to severe, life-threatening reactions (anaphylaxis) that require immediate medical intervention.