Diet Focus

For some people, eating healthy takes a little more effort than it does for the rest of us. People suffering from food allergies must temper their efforts to stay healthy with a keen awareness of what goes into making their food. However, armed with a little information and a watchful eye, people with food allergies can enjoy their food as much as any other person. It just takes someone willing to be vigilant.

What are Food Allergies?

People frequently use the term "food allergy" to describe a variety of adverse physical reactions to foods. But a true food allergy is an abnormal response of the body's immune system to certain foods or ingredients.

An abnormal response occurs when the immune system overreacts to substances (usually proteins) that are harmless to most people and starts releasing antibodies called immunoglobulin E (IgE). These antibodies attached themselves to special cells called mast cells, which then release substances that cause a variety of allergic reactions.

The Culprits

About 90% of all food allergies are caused by just a few ingredients. The most common allergens include:

• cow's milk
• egg whites
• shellfish and fish
• legumes
• peanuts, walnuts, pecans, almonds and cashews
• wheat
• soybeans

A number of foods commonly believed to be allergenic are not. Chocolate, strawberries, tomatoes, citrus fruits and corn are often blamed for allergic reactions, but they are rarely the cause. Sugar is not an allergenic food, although it is often thought to be.

The majority of adverse reactions to foods are not true food allergies, but rather are sensitivities or intolerances. The symptoms are similar, but these reactions -- unlike allergies -- either don't involve the immune system, or they involve a different part of the immune system than true allergies do.

A Note on Additives

More than 2,000 food additives are commonly used today, including:

• preservatives
• conditioners
• flavorings
• colorants
• sweeteners

The following additives are most widely associated with allergic reactions:

• Sulfites -- preservatives
• Parabens -- preservatives
• Nitrates/Nitrites -- preservatives
• MSG -- a flavoring
• FD and C Dyes -- colorants
• BHA, BHT -- antioxidants
• Benzoates -- preservatives
• Aspartame -- a sweetener

Sulfites are among the most widely used additives in prepared foods, and they may also be the most likely culprits when it comes to reaction incidents. Sulfiting agents are used to preserve foods and sanitize containers for fermented beverages. When checking food labels, keep in mind that some sulfites are also known as SO2; these include sulfur dioxide, sodium or potassium sulfite, bisulfite and metabisulfite. Sulfites are commonly found in baked goods, teas, condiments, relishes, processed seafood products, jams and jellies, dried fruit, fruit juices, canned vegetables, dehydrated vegetables, frozen vegetables, soup mixes, beer, wine, wine coolers and hard cider.

Until recently, the highest levels of sulfites were in restaurant salad bars. However, because of the growing rate of reaction to sulfites, the Food and Drug Administration banned their use on fruits and vegetables intended to be served raw. The agency also mandated labeling for packaged foods that contain more than 10 parts per million of any sulfiting agent, so that people sensitive to sulfites may easily identify products they should avoid. Alcohol consumption for people who are allergic to sulfites is also discouraged.

Looking for the Symptoms

Food allergies most commonly affect the gastrointestinal tract, the skin and the respiratory system. Typical symptoms include:

• nausea
• vomiting
• diarrhea
• skin rash
• breathing difficulty
• sneezing
• itchy, watery eyes

In severe cases, anaphylactic shock may occur even if the allergic person has consumed only traces of the offending food. The signs of anaphylactic shock include itching and flushing of the skin, followed by severe vomiting, diarrhea, hypotension and constricted respiratory passages.

Less sensitive people may be better able to tolerate small amounts of the allergens in the foods they eat. They also may tolerate the allergen if they are not under stress.

Who Gets Food Allegies?

Although two out of five Americans believe that they have food allergies, only about 1 percent of adults suffer from true food allergies. Children are more susceptible -- up to 7 percent may be affected -- but their symptoms often subside as they get older. Some children who as infants had allergies to certain foods are able to eat them again by the age of 3.

The later in life food allergies appear, the less likely they are to go away. Also, people with allergies to plant foods may have cross-allergies. For example, if they are allergic to peanuts, they may also be allergic to other legumes, such as green peas, soybeans, and lentils.

Diagnosing the Problem

Diagnosis usually begins with a physical examination by a physician certified by the American Board of Allergy and Immunology. The qualified allergist will take a detailed medical history.

To help determine which foods affect you adversely, you might be asked to keep a diary of what you eat every day and record any symptoms you experience. You may also be asked to follow an elimination diet, in which all foods that are not very well tolerated are eliminated. These foods are then gradually re-introduced one by one to see if you develop a reaction to them. This process is called a food challenge.

Other diagnostic tools are skin and RAST tests. Whether foods flagged by a skin test actually cause problems can be confirmed by a food challenge.

If the methods described so far do not reveal the source of your symptoms, the gold standard for evaluating allergies is the double-blind challenge test. In this test, the patient takes capsules of dried food suspected of causing reactions, along with capsules containing non-reactive substances; neither the doctor nor the patient knows which is being administered at any given time. If symptoms occur only with the food being tested, the patient is allergic to that food. Double-blind challenges are valuable because they can detect and rule out allergies or intolerances to many foods and other substances such as additives. They also eliminate non-food influences that can cause symptoms, including psychological factors.

Clinical ecologists, cytotoxic testing and sublingual testing are not recommended for reliably determining true food allergies.

What You Can Do

Once a food allergy has been diagnosed correctly, the only effective treatment is strict avoidance of the offending food. This can be tricky if you are allergic to something which is used as one of several ingredients in a dish and which cannot easily be detected by sight or smell. (Peanut oil is a good example.) Here are some suggestions that will help keep you from inadvertently ingesting a food to which you are allergic.

If you are in a restaurant, take the following precautions to help insure a reaction-free experience:

1. Identify your allergy.
2. Ask how the dish was prepared.
3. Never taste food before asking questions.

When you are at the supermarket, you also need to be aware of how your allergy affects your choices. For instance:

1. Always read the labels on packaged foods.
2. Become familiar with unfamiliar names used on labels; below is a chart that lists the names for common food allergens:

   Milk	Eggs	Wheat	Corn
   Lactalbumin	Albumin	Gluten	Corn starch
   Caseinate	Vitellin	Cracked Wheat	Corn Sugar
   Lacotglobulin	Ovovitellin	Graham Flour	Corn Flour
   Sodium Caseinate	Ovomucin	Durum Flour
   Curds	Ovomucoid
   Casein	Globulin
   Whey	Livetin

3. If you have questions about favorite foods, contact the manufacturers of the product.

Your allergist may recommend a consultation with a registered dietitian to help you make food choices.

If you are allergic to milk protein, you may find it helpful to choose Kosher foods at the supermarket. Since Orthodox Jews are required to keep milk and meat products separate, a Kosher symbol on a food product is a clear indication of the product's dairy content. The term parve or pareve after the symbol of the Kosher agency that evaluates the contents means there is no dairy food in the product. For example, the terms K pareve and U pareve signify that no dairy foods are used in the product. A D after the Kosher agency that evaluates the food means the product contains dairy products. For example, KD or UD means dairy is present. The symbols usually appear on the front label next to the product name. If a product does not have a D or the word pareve or parve next to the Kosher agency symbol, read the ingredients list before assuming that the product does or does not contain dairy.

Putting It All To Work

Once you determine -- with the help of a physician -- that you have a food allergy, it becomes very important to eliminate the allergen from your diet. Some suggestions for helping you in restaurants and at the market were made earlier in this article. However, for those people allergic to common foods like milk, eggs and wheat, some extra help in the kitchen might be needed. To get you started, here are some recipes that focus in on eliminating some of these ingredients. Check out some of the larger bookstores in your area or online for cookbooks that focus on your particular allergy too.

More Resources

For more information about food allergies and what you can do to help avoid a reaction, consult your physician and visit any of the following web sites:

• American Board of Allergy and Immunology
• Allergy ABC's
• Allergies - Doctor's Guide to the Internet
• Northern Allergy Centre's Allergy and Health Information