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Food Allergy, or Food Intolerance?

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"The Healthy Geezer" answers questions about health and aging in his weekly column.

Question:  Fruit juices give me a stomachache. Do you think I'm allergic to them?

Answer: I never diagnose because I'm a journalist, not a physician. If you have a problem digesting fruit juices and this is interfering with your life, you should see your doctor and get a check-up.

Meanwhile, you might want to keep a diary of all the foods you eat. Doing this will isolate those foods that are triggering digestive problems. The intensity of your reaction can determine whether or not you are allergic to certain foods, or have a food intolerance.

A food allergy is an abnormal response to a food that's triggered by the body’s immune system. This type of reaction occurs quickly—sometimes within minutes. Reactions include itching in the mouth, vomiting, diarrhea and abdominal pain. You may experience a drop in blood pressure, asthma and skin reactions such as hives or eczema. An allergic reaction to food can cause serious illness and, in some cases, death.

Sometimes, a reaction to food is not an allergy, but a "food intolerance." Food intolerance is more common than food allergy. The immune system doesn't cause the symptoms associated with a food intolerance, though they can be similar to those of a food allergy.

Many people think they have food allergies. However, most symptoms are caused by intolerances to foods such as wheat and other grains, the sugar in fruits and honey, dairy products and corn products.

If fruit juices are giving you a stomachache, there is a possibility that you have a fructose intolerance. Fructose is a sugar that's found in fruits, honey and some syrups. It's also a basic component in table sugar (sucrose), and it's used to sweeten many processed foods and beverages.

In addition, sorbitol — a sugar alcohol — is converted to fructose during digestion. Sorbitol is a sugar substitute often used in diet drinks, ice cream, mints, cough syrups and sugar-free chewing gum.

You should avoid foods containing fructose. In addition to fruits, honey, syrups and table sugar, watch out for high-fructose corn syrup, powdered sugars, regular sodas, flavored waters, sports drinks and sweetened milks. Read food labels carefully to avoid fructose.

The term fructose intolerance covers two conditions: hereditary fructose intolerance and fructose malabsorption. People with hereditary fructose intolerance, a rare genetic disorder, lack an enzyme that breaks down fructose. This is a serious disorder that can lead to liver and kidney damage.

People with a fructose malabsorption have trouble digesting fructose. While fructose malabsorption doesn't cause organ damage, it can cause abdominal pain, gas, bloating and diarrhea. A doctor can confirm if you have one of these conditions.

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All rights reserved @ 2013 by Fred Cicetti.

Fred Cicetti is a contributing writer for Live Science who specializes in health. He has been writing professionally since 1963. Before he began freelancing, he was a reporter, rewriteman and columnist for three daily newspapers in New Jersey: The Newark News, Newark Star-Ledger and Morristown Record. He has written two published novels:" Saltwater Taffy—A Summer at the Jersey Shore," and "Local Angles—Big News in Small Towns."