Food Allergies, Intolerance, and Sensitivities

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If you find that you get sick after eating a particular food, you may wonder if you have a food allergy or intolerance. Understanding the difference between the two can help you to see if you truly have a problem. Read on to learn how food allergies and intolerance differ, and how they relate to IBS.

Food Allergies

Food allergies are diagnosed when a person’s immune system responds after they eat a certain food. The response involves IgE antibodies that stimulate the release of certain chemicals, including histamines, that cause physical symptoms. In addition to the symptoms that are typically associated with an allergic response -- such as tongue and throat swelling, difficulty breathing and skin hives -- food allergies can also cause gastrointestinal symptoms of vomiting, diarrhea, and abdominal cramping. Symptoms usually show up immediately or within the first two hours after eating the problematic food. Although it is estimated that 6 to 8% of children suffer from food allergies, food allergies in adulthood are relatively rare, affecting less than 3% of the population. If you think you have a food allergy, it is recommended that you see an allergist for specialized testing.

Food Intolerance

A food intolerance differs from an allergy in that there is no immune system response to the offending food. When a food intolerance exists, the problem is at the level of the digestive system – the GI system’s inability to digest the food causes uncomfortable gastrointestinal symptoms. In contrast to a food allergy, a person with a food intolerance can typically eat small amounts of the identified food without experiencing symptoms.

Food Sensitivity

Sometimes a particular food may bother a person without there being any medical reason for this to be the case. Here you will find a list of common foods that may cause difficulty for sensitive systems:

Celiac Disease

Sometimes referred to incorrectly as a gluten intolerance, celiac disease is an autoimmune response to the consumption of foods containing the protein, gluten. Gluten is most commonly found in products containing wheat, rye or barley. When a person with celiac disease eats a food that contains gluten, the immune system's response damages the lining of the small intestine, causing a wide variety of potential symptoms. This damage can interfere with the body's ability to absorb important nutrients. Current medical guidelines recommend that IBS patients be screened for the presence of celiac disease.

What Should You Do if You Suspect a Food Problem?

If you are concerned that you have a food allergy or intolerance, you should discuss this with your doctor. What you should not do is to begin to arbitrarily restrict your diet, which could lead to nutritional deficits. Food allergies and intolerance are fairly rare and your symptoms could be caused by a number of other factors, e.g. stress, hormonal changes, or a different digestive disease. Your doctor is in the best position to help you to narrow down the problem. To do this, your doctor may recommend the use of a food diary and/or an elimination diet.

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Article Sources

  • Lack, G. “Food Allergy” New England Journal of Medicine 2008 359:1252-1260.
  • Whorwell, P. “ Dietary Aspects of Irritable Bowel Syndrome (IBS)” Digestive Health Matters 2007 16:6-7.