Food Intolerance and Sensitivity

Food intolerance or food sensitivity is a negative reaction to a food that may or may not be related to the immune system or to food poisoning. It may be caused by the absence of specific enzymes which are needed to digest a food substance or to the bodys responses to certain food chemicals both natural and artificial.

Symptoms of food intolerance vary greatly and may be mistaken for the symptoms of an allergy. Food allergies or food intolerances affect nearly everyone at some point, but only about three percent of children have clinically proven allergic reactions to food and only about one percent of adults have food allergies.

Most Common Allergies

In adults, the most common foods to cause allergic reactions include shellfish such as shrimp, crayfish, lobster, and crab; peanuts, eggs, tree nuts, and fish.

The pattern in children varies somewhat. The most common food allergens that cause problems in children are eggs, milk, and peanuts. Adults usually do not lose their allergies, but children can sometimes outgrow them.

Children are more likely to outgrow allergies to milk or soy than allergies to peanuts, fish, or shrimp. If someone has a life threatening reaction to a certain food, their doctor will counsel the patient to avoid similar foods which might trigger this reaction.

Differential Diagnosis

A differential diagnosis means distinguishing good allergy from food intolerance or other illnesses. One possibility is the contamination of foods with microorganisms, such as bacteria and toxins. Contaminated meat can sometimes mimic a food reaction when it is really a type of food poisoning.

Natural substances, such as histamine, that occurs in foods and can stimulate a reaction similar to an allergic reaction. Histamine can reach high levels in cheese, certain kinds of fish, and some wines.

If someone eats one of these foods with a high level of histamine, that person may have a reaction that strongly resembles an allergic reaction to food. This reaction is called histamine toxicity.

Adverse Reactions

Another type of food intolerance is an adverse reaction to certain products which are added to food to enhance the taste, provide color, or protect against the growth of microorganisms.

Sulfites can occur naturally in foods or are added to enhance crispness or prevent mold growth. Sulfites in high concentrations can sometimes pose problems for people with severe asthma. Sulfites can give off a gas called sulfur dioxide.

There are several other diseases that share symptoms with food allergies, including ulcers and cancers of the gastrointestinal tract. These disorders can be associated with vomiting, diarrhea, or cramping. Gluten intolerance is associated with the disease called gluten sensitive enteropathy or celiac disease.


Food intolerance is treated by dietary avoidance. Once a patient and their doctor have identified the food to which the patient is sensitive, the food must be removed completely from their diet. The patient must read lengthy and detailed ingredient lists on each food they are considering eating.

Many allergy producing foods such as peanuts, eggs, and milk, appear in foods in which one would not normally associate them with. People can avoid most of the things to which they are sensitive if they read food labels carefully and avoid restaurant prepared foods that might contain ingredients that they are allergic to.