An elimination diet functions as a test, determining whether patients may have a sensitivity to certain foods. Initially, patients stop eating foods suspected of causing illness. Then, after a suitable period of time (often 10–14 days), they review the patients' symptoms. If significant improvement has occurred, it is assumed that an allergy or intolerance to certain foods may be involved. These suspect foods are then reintroduced into the diet, one by one. When symptoms return (usually within three days), the problematic food is identified and removed from the diet.
Elimination diets are potentially useful in identifying hard-to-detect food intolerances that proponents believe are responsible for a wide range of ailments. These include constipation, headaches, migraine, infections of the ear or sinuses, frequent colds, post nasal drip, chronic nasal congestion, sore throats, chronic cough, eczema, hives, acne, asthma, pain or stiffness in the muscles or joints, heart palpitations, indigestion, ulcers of the mouth, stomach, or duodenum, Crohn's disease, diarrhea, yeast infections, urticaria, edema, depression, anxiety, hyperactivity, weight change, and generalized fatigue.
The following lists of appropriate and inappropriate foods for an elimination diet represent general guidelines. Elimination diets vary according to practitioner and the specific symptoms or allergy.
Foods that may be prohibited in an elimination diet include those containing:
- Additives: monosodium glutamate, artificial preservatives, sweeteners, flavors, or colors.
- Alcohol: beer, ale, stout, porter, malt liquors, wine, coolers, vodka, gin, rum, whiskey, brandy, liqueurs, and cordials.
- Citrus fruits: oranges, calamondins, tangerines, clementines, tangelos, satsumas, owaris, lemons, limes, kumquats, limequats, and grapefruit.
- Commonly eaten foods: anything consumed more than three times weekly, as well as foods that are craved, or that cause a feeling of weakness.
- Corn: as well as corn syrup or sweetener, corn oil, vegetable oil, popcorn, corn chips, corn tortillas.
- Dairy products: milk, milk solids, cheese, butter, sour cream, yogurt, cottage cheese, whey, and ice cream.
- Eggs: both yolks and whites.
- Gluten: any pasta, breads, cakes, flour, or gravies containing wheat.
- Maple syrup.
- Sugar: candy, soft drinks, fruit juices with added sugar or sweetener, cakes, cookies, sucrose, fructose, dextrose, or maltose.
Foods that may be allowed include:
- Cereals: puffed rice or millet, oatmeal, or oat bran.
- Daily multivitamin: this is especially important during extended dieting to replace missing nutrients.
- Fats and oils: soy, soy milk, soy cheese, sunflower oil, safflower oil, flaxseed oil, olive oil, and sesame oil.
- Fruits and vegetables: typically, anything except corn and citrus fruits. Some practitioners suggest fruit be consumed in moderation, and preferably whole as opposed to juices.
- Grain and flour products: rice cakes or crackers, rye or spelt bread (both must be 100% with no added wheat), kasha, rice, amaranth, quinoa, millet, oriental noodles, other exotic grains.
- Legumes: soybeans, string beans, black beans, navy beans, kidney beans, peas, chickpeas, lentils, tofu. Canned beans should be avoided unless they are free of preservatives and sugar.
- Seeds and nuts: must not contain sugar or salt. Nut butters are allowed if they meet this requirement and are organic.
- Water: two quarts daily. Preferably bottled, as tap water contains potential allergens including fluoride and chlorine.
- Other: honey, white vinegar, salt, pepper, garlic, onions, ginger, herbal teas, coffee substitutes, spices or condiments (mustard, ketchup) that are free from sugar, preservatives, and citrus. These products can commonly be found at health food stores.
An important complement to any elimination diet is a food diary, in which all dietary consumption is recorded, along with any subsequent symptoms. Patterns should be evident after about one month of record keeping.
As with all therapies, anyone considering an elimination diet should weigh the potential benefits against the risks. The decision, according to some, is comparable to deciding to take a prescribed medication, and should be done only under the supervision of a competent medical practitioner.
Elimination diets should never be used by individuals with severe food allergies, as reintroducing a suspect food may provoke an asthma attack, anaphylactic shock, or other dangerous reaction. Generally, an elimination diet will only be used when symptoms are believed to be related to just one or two suspect foods.
Patients need to know that following a strict elimination diet is not an easy matter. It is extremely important to read packaged-food labels carefully, because many processed foods contain monosodium glutamate, sugar, and other substances that may be prohibited. It is almost impossible for elimination-diet patients to eat in restaurants, at school, or at the homes of friends. The resulting isolation must be considered as part of the decision to undertake an elimination diet. Patients should also consider whether they have sufficient time for the extra planning, shopping, and food preparation involved.
Elimination-diet patients should be vigilant to replace any nutrients missing from their restricted diet. For example, calcium supplements may be advisable for someone eliminating dairy products from the diet. Needless to say, any prescribed medications should be continued during any diet.
Putting a very young child on an elimination diet may endanger the child's nutrition and normal growth. A breastfeeding mother may harm both her own health and that of her infant if she undertakes an elimination diet during lactation.
The most significant side effects of an elimination diet are nutritional disorders resulting from a prolonged, highly restrictive diet, and the risk of a serious reaction as suspect foods are re-introduced to the diet. Some proponents also caution that patients consuming a very limited variety of foods risk becoming allergic to those very foods. For these reasons, both professional supervision and substitution of missing nutrients both essential.
Research & general acceptance
Elimination diets are widely used by medical doctors, but considerable differences of opinion exist over the range of illnesses that may be caused by food allergies or intolerances. Many physicians and researchers question the role of allergies in migraine, rheumatoid arthritis, osteoarthritis, and other conditions. Some doctors suggest that elimination diets should be used only after other diagnostic methods have been tried, including history-taking, skin tests, blind food challenges, and radioallergosorbent testing.
Training & certification
Because of the risks involved, elimination diets should be undertaken only under competent medical supervision. Some patients may wish to consult an allergy specialist.
Brostoff, Jonathan, and Linda Gamlin. Food Allergies and Food Intolerance: The Complete Guide to Their Identification