Food Allergies & Intolerances
Are you allergic to any foods? Are there certain foods that your body doesn’t tolerate well? You may be surprised to know that only around 4-8 percent of children and 2 percent of adults have true food allergies but many more than that have intolerances to certain foods, with estimates at 45% and higher. An allergist can help determine whether you suffer from a true allergy or a food intolerance.
What is a food allergy?
A food allergy is an abnormal reaction to food that involves the body’s immune system. When an offending food is eaten, the body produces and antibody called Immunoglobin E (IgE) in response to that food. The reaction may be mild and involve skin reactions such as hives or eczema around the mouth or on other areas of the body. Sometimes a mild allergy may affect the GI tract and cause nausea, vomiting, or diarrhea. Other food allergies are more severe, resulting in asthmas-type symptoms, difficulty breathing, coughing, or wheezing. In some people food allergies can be very severe and result in anaphylaxis, a reaction that involves the whole body and can be fatal.
The most common foods that cause allergic reactions are peanuts, tree nuts, milk, eggs, fish, shellfish, wheat, and soy.
What is a food intolerance?
A food intolerance is an abnormal response to a food that does not involve the immune system. Intolerances are more common than food allergies. Symptoms may be similar to those of a food allergy such as GI problems, hives, or itching around the mouth, chronic fatigue, eczema and joint pains. Intolerance symptoms are generally mild and may be inconvenient but are rarely acutely life-threatening. However, there is an increasing amount of research pointing to food sensitivity and a connection to chronic inflammation which may increase a person’s risk of heart disease, rheumatoid arthritis, Crohn’s disease and diabetes.
How can I tell the difference?
Sometimes it is hard to know the difference. Many people find it helpful to keep a diary of foods eaten and symptoms over a period of a few weeks. This can help you identify what foods are causing you problems and allow you to link symptoms with specific foods.
If you have repeated symptoms that you think are food-related it is probably a good idea to visit an allergist to determine if you have an allergy or an intolerance. The doctor can do blood testing or skin testing and identify a true food allergy.
Food allergies can also be diagnosed in part by a “food challenge” - by introducing a food and observing for an allergic reaction to that food. This type of testing should be supervised by a doctor.
Why does it matter?
Avoiding particular foods for a lifetime can be difficult and unnecessary and might result in a diet that is not well-balanced. A healthy diet contains a variety of foods without avoiding any one food or food group without a good reason. That’s why identifying true food allergies is important before eliminating any food from the diet.
What is the treatment?
At this time the only treatment is to avoid the food that you are allergic to. This can be harder than it seems because you must read carefully to make sure you are avoiding the allergen completely. For example, if you are allergic to eggs you must avoid all components of eggs and any egg that is found in other foods, especially if your reaction is very severe.
Those who have anaphylactic reactions (reactions that involve the entire body and can be fatal) to food must carry injectable epinephrine that should be administered as soon as possible after the allergic reaction begins.
Should I avoid all foods that I am allergic to?
Probably. However, some people do outgrow allergies. If you have been tested by an allergist and you know you are allergic to a food you should not re-introduce it into your diet without consulting your doctor.
If you have a food intolerance, there is no reason why you can’t re-introduce that food every now and then to asses if your body still has a reaction to that food.
Adapted from www.RD411.com
References
The Food Allergy Network. Accessed January 2007. Available at www.foodallergy.org.
American Academy of Allergy Asthma and Immunology. Tips to Remember: Food Allergy. Accessed January 2007. Available at www.aaaai.org/patients/publicedmat/tips/foodallergy.stm
International Food Information Council. Food Sensitivities, Allergies, and Intolerances: Separating Fact from Fiction. Food Insight, July/August 2003. Accessed January 2007. Available at http://www.ific.org/foodinsight/2003/ja/foodsensfi403.cfm?renderforprint=1
