What are Food Allergies? By Geraldine Harrison-Foote, UNEP Educator

We live in a different world today. Yes, there are many things that are unusual, but have you ever noticed how many people have allergies? In particular, have you noticed how many people are affected by food allergies? "An estimated 150 Americans die each year from severe allergic reactions to food," according to Dr. Hugh Sampson, food allergy expert and director of the Elliot and Roslyn Jaffe Food Allergy Institute at Mount Sinai School of Medicine in New York City.

This article focuses on foods that trigger allergic reactions, along with causes, symptoms, prevention, and treatment options for food allergies. Now let's begin by defining the word allergy. An allergy or an allergic reaction can be caused by food, flowers, dyes, perfumes, dust, and animals, such as cats or dogs. An allergic reaction is simply an abnormal immune response by the body that is triggered when it comes into contact with something it doesn't agree with and uses that response or reaction to fight it off.

A food allergy is defined as a "reaction of the body's immune system to something in food or an ingredient in food---usually a protein." Food allergies often occur over time, yet some results are immediate while others are delayed. The process of developing a food allergy takes place when a food item is partially broken down instead of going through its natural metabolic state where it breaks food down into smaller components, such as glucose, amino acids, and short chain fatty acids. These partially metabolized components travel across the intestinal barrier, circulating in the subsurface of the intestinal tract. As a result, an inflammatory or allergic reaction occurs in the wall of the intestinal tract.

After the partially metabolized food has crossed over, it then travels to the liver where it is recognized as a foreign particle because it's partially digested and has not broken down into its simpler forms as discussed earlier. The immune system is alerted by the cells in the liver to react to the foreign matter, which results in an allergic reaction. Unfortunately, the same foods that cause the allergic reaction are consumed over and over again with similar symptoms present and new ones emerging.

As stated previously, some food allergies are immediate and others are delayed. There are certain symptoms that follow if someone consumes a food product that causes an immediate allergic reaction. Common symptoms include hives and eczema, rashes, and gastrointestinal symptoms, such as nausea, diarrhea, and vomiting. Other symptoms that can result from a food allergy are sneezing, runny nose, and, shortness of breath. In some extreme instances a more severe reaction called anaphylaxis (an-a-fi-LAK-sis) may occur.

Anaphylaxis is a systemic allergic reaction that is sudden, severe, and potentially fatal, causing adverse affects to the skin, throat, respiratory and gastrointestinal tracts, and the cardiovascular system. Symptoms can occur within minutes up to two hours, and in rare instances, may occur up to four hours. Contact is generally made with the allergy causing substance, resulting in mild to life-threatening reactions. In such cases, it is necessary to seek immediate medical treatment when anaphylaxis occurs that may include an "injection of epinephrine (adrenaline) to open up the airway and blood vessels."

Any food can cause an allergic reaction in some people, but there are eight foods that "account for 90 percent of all food-allergic reactions." These foods are milk, eggs, tree nuts, peanuts, soy, wheat, fish, and shellfish. Normally, eggs, milk, peanuts, wheat, and soy are the primary causes of food allergies in children. Food allergies not easily outgrown are tree nuts, peanuts, fish, and shrimp. Unfortunately, many adults do not outgrow allergies over time.

There are a few steps to remember when treating food allergies and symptoms.

1. Avoid food or ingredients that trigger an allergic reaction.
2. Check and inquire about ingredients. Because of the seriousness of food allergies, food labels and menu items should be checked for food allergens before being eaten or purchased. It is imperative to ask about food ingredients at restaurants or at another person's home in order to prevent a serious reaction form occurring.
3. Become informed by reading food labels. Reading food labels is important to avoid known allergens. The United States and other countries have included simple terms for food ingredients. For example, milk is listed as "milk" instead of "casein" or wheat for "gluten."
4. Have an emergency plan in place. Food allergies that cause anaphylactic reactions can be life threatening and should be avoided at all costs. People who have a history of severe allergic reactions should wear an identification bracelet describing the allergy, and carry and know how to inject epinephrine and antihistamines. Other people who are around the allergic person should also know how to inject the drug.

Food allergies are serious and should be diagnosed by an allergy specialist. This person is called an allergist or immunologist. Visit the following websites for more information on food allergies:

American Academy of Allergy, Asthma and Immunology
American College of Allergy, Asthma and Immunology
American School Food Service Association
Food Allergy & Anaphylaxis Network
Department of Food Science
Grocery Manufacturers of America
International Food Information Council Foundation
Food Products Association
National Restaurant Association

References

Formanek, Ray, Jr. (July-August 2001). Food allergies: When food becomes the enemy. FDA Consumer Magazine. United States Food and Drug Administration. Retrieved June 13, 2006.

International Food Information Council Foundation. (1998). Food allergy resources. Allergies. Retrieved June 13, 2006.

International Food Information Council Foundation. (1998) Understanding food allergy. Allergies. Retrieved June 13, 2006.

Tidwell, Judy. (2006). Food allergies and intolerances. Allergies. Retrieved June 13, 2006.

The Food Allergy and Anaphylaxis Network. (2006). Frequently asked questions. Retrieved June 13, 2006.

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