Allergies and Intolerances

Food sensitivities are classified as either an allergy or intolerance. Both mean that certain foods must be eliminated from the diet, but the reactions occur in different body functions.

Food allergies are an immune system response. The food is interpreted by the body as an attacking substance, usually remembered from a previous exposure, and the body reacts by sending antibodies to fight it. The resulting symptoms can be mild, or life threatening, and include rash, hives, chest pain, shortness of breath, swelling of airways, and anaphylaxis.

Food intolerance is a response from the digestive system and is usually not life threatening. Intolerance occurs if the body does not possess the enzymes or chemicals it needs to break down a food and digest it. Symptoms are unpleasant and can cause illness and long-term health problems.

With both allergies and intolerances, the severity of the reaction varies with the individual.


Anaphylaxis is an allergic reaction that occurs from eating, breathing, touching, or injecting an allergen. The name comes from the Greek ana, meaning “against,” and phylaxis, meaning “protection.” Symptoms can be mild or severe, ranging from swelling, itching, vomiting, fainting, and difficulty breathing to a sudden drop in blood pressure. Severe symptoms can result in death within minutes if not treated immediately.

The most common food sensitivities have prompted the creation of a variety of products to support a normal and varied diet. Manufacturers are continually creating new foods made without the most common problematic ingredients. Cross-contamination is a particular issue, and more and more products are being manufactured separately to prevent accidental exposure.

People who suffer from these problems must learn to read labels carefully and get in the habit of asking friends what is in the food they are cooking. Dining at restaurants is considerably more difficult. Calling ahead to discuss allergies is a typical approach, and these sensitive diners tend to stick with the restaurants they find accommodating.


Dairy products cause both allergies and intolerances. Milk allergy is an immune system response to milk protein. This is the most common allergy found in infants and young children, but they often outgrow it. Symptoms include rashes, hives, gastrointestinal distress, and breathing problems. Anaphylaxis is rare. Those suffering from milk allergies must avoid all dairy products, foods made with dairy products, and foods containing whey or casein.


Casein is a protein in milk that is used in food manufacturing as a binder. It can appear in nondairy foods, such as soy cheese or nondairy creamer, so milk-sensitive people need to look for casein on food labels.

Intolerance to dairy is specifically an intolerance to milk sugar, or lactose. The body is missing lactase, an enzyme needed to digest milk sugar. Several hours after eating dairy, bloating, abdominal pain, gas, and diarrhea occur.

Some who are lactose intolerant can consume foods with trace amounts of dairy. Yogurt does not cause distress because its amazing bacteria helps to consume lactose fast—so fast that the body doesn’t have time to react to having eaten it.

There are several dairy products on the market that are specially treated for the lactose intolerant, such as lactose-free cheese, milk, and ice cream.

For allergies, all milk products must be avoided. Substitutes include soy, rice, and almond milks, margarine, and a host of other nondairy products, including ice cream, chocolate, cheese, and yogurt. Calcium is an essential element of the diet that must be replaced with calcium-rich vegetables and supplements.

Wheat and Gluten

There are several proteins in wheat that can cause an allergy or intolerance. These proteins give wheat its unique elasticity and make it an excellent binder. For that reason, wheat flour is found in a surprising amount of foods, including ketchup and ice cream. Those with sensitivities must become expert label readers.


Gluten is the most common cause of wheat sensitivity. Gluten is composed of two proteins, glutenin and gliadin. Together, when moistened and agitated, they create elasticity. This elasticity, among other things, allows bread dough to rise.

An allergy or intolerance to a specific protein may include other grains in the same family as wheat (triticea), including barley, rye, and oats. Wheat is also found in other forms that go by different names, including farina, bran, graham, bulgur, durum, semolina, malt, and starch.

To cook without wheat, substitute one tablespoon of wheat flour with one and a half teaspoons (i.e., half the amount) of cornstarch, potato starch, arrowroot starch, rice flour, or tapioca. Larger quantities of flour can be replaced with a more or less equal amount of corn meal, potato flour, or rice flour. Substitution ratios will vary depending on the recipe, so experimentation is recommended.

Celiac disease is an autoimmune disorder of the small bowel. Two wheat proteins, gliadin and glutenin, cannot be modified by enzymes, and the immune system reacts with inflammation that interferes with the absorption of nutrients. Luckily, there are many gluten-free food options available today.


Peanuts and tree nuts are among the most common food allergies. They are so common that nut-free products, restaurants, and even schools are becoming commonplace.

Nut allergies can be severe. Symptoms can include tingling mouth and lips, hives, swelling in the throat, asthma, vomiting, cramps, anaphylaxis, fainting, and unconsciousness. Death can occur as a result of obstruction of airways and extremely low blood pressure.


It is possible to be cross-contaminated by your pets. Pet bedding and food commonly contain nut derivatives. If you have a severe allergy to nuts, look for nut-free dog food, or you may find yourself faced with potentially hazardous drool.

Like wheat, nuts are found in an enormous number of products. As of 2006, labels are required to clearly state if a product contains nuts. Watch for nut-derived ingredients in soup, gravy, chili, ice cream, chocolate, and candy, as well as pet foods and bedding.

Nut oils are difficult to remove by washing, so cross-contamination of nut residue is a real concern. Avoid buffet dining, in which ladles and serving utensils can migrate between foods. Avoid dining out on cuisines that are known to use lots of nuts, including Asian, African, and Mexican. Avoid fried foods, as fryer oil often contains peanut oil. Above all, teach your friends and family to recognize anaphylaxis.

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