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Allergy vs. Intolerance

Adverse reactions to foods are common, but very few are actually food allergies. According to Dr. James T. Li, a Mayo Clinic allergy specialist, only 4 percent of adults have true food allergies, but about 8 percent of children under three have them. Food allergies and intolerances can often have very similar symptoms, but allergies can be much more serious. One may be able to tolerate small amounts of a food that causes intolerance; that is not the case with an allergy.

  1. Food Allergies

    • A food allergy affects the system by responding to the specific food in a number of ways. First, the immune system mistakes the food for a harmful substance, and the body then begins to produce antibodies to fight the food. After the initial allergic reaction, if the food is consumed again in any amount the created antibodies will sense this and alert the immune system. The immune system reacts by releasing histamine and other chemicals in to the blood stream and produces food allergy symptoms.

    Food Intolerance

    • Food intolerances can occur for a number of reasons. The most common food intolerances are likely created by the lack of an enzyme needed to digest a food, such as lactose intolerance. Irritable bowel syndrome is often mistaken as a food allergy or food poisoning. Others may have sensitivity to food additives, such as sulfites, often found in wine and canned goods, which can trigger asthma attacks. Celiac disease is a chronic digestive condition often mistaken for food allergies and is triggered by gluten and foods containing wheat, barley and rye. Often people suffer from food aversions caused by psychological factors that may create physical symptoms similar to those of an allergy.

    Signs and Symptoms

    • Allergic reactions to food often occur rapidly once the food has been ingested, and the onset of symptoms is sudden. A food allergy can often cause hives, a tingling sensation in the mouth and a swelling of the face, tongue and throat. This can cause difficulty breathing, dizziness and fainting. Allergies can also cause nausea, vomiting and diarrhea, common symptoms of food intolerance. It takes longer for symptoms to manifest with food intolerance, and very rarely do they include swelling and hives.

    Common Food Allergies and Intolerances

    • The most common foods that cause allergic reactions are dairy, eggs, wheat, soy, peanuts, tree nuts and fish. This is not an exhaustive list, and people can be allergic to many types of foods. It is common for some allergies, such as to milk, to be present in childhood and end by adulthood. Fish and nut allergies typically extend into adulthood. Some foods that commonly cause food intolerance are dairy, wheat, peanuts and tree nuts.

    Diagnosing Allergies and Intolerances

    • A doctor can perform a simple skin and blood test to check for any allergies. It is often suggested to simplify the diet and keep a food diary to identify any foods that may be causing intolerance.

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