People with full blown celiac or lower level gluten sensitivity usually need to avoid gluten products indefinitely as they are more persistent than other allergens.  The main cause of gluten sensitivity as described by the researchers is a cell-mediated, immunological reaction to certain components of certain dietary glutens. Most of these abnormal responses are proteins contained in wheat, rye and barley. Previously oats were also considered to be a trigger but recent studies suggest that 95% of celiacs can tolerate the specific oat glianden so long as the oats are processed where they cannot be contaminated.  Corn, rice, buckwheat; millet; amaranth; and quinoa are safe for celiac disease patients. These commodities contain different type of gluten which does not appear to trigger celiac disease directly.

The following list shows examples of many foods that are allowed or avoided, but it is not a complete list. It is important to read all food ingredient lists carefully to make sure that the food does not contain gluten.

Beverages
Allowed: Coffee, tea, carbonated drinks, wine made in U.S., rum, some root beer.
Avoid: Ovaltine, malted milk, ale, beer, gin, whiskey, flavored coffee,  herbal tea with malted barley.

Milk
Allowed: Fresh, dry, evaporated, or condensed milk; cream; sour cream; whipping cream; yogurt.
Avoid: Malted milk, some commercial chocolate milk, some nondairy creamers.

Meat, Fish, Poultry
Allowed: Fresh meats, fish, other seafood, and poultry; fish in canned oil, brine, or water; some hot dogs and lunch meats.
Avoid: Prepared meat (especially sausage and coated meats) containing wheat, rye, oats, or barley; tuna canned in vegetable broth.

Cheese
Allowed: All aged cheese, such as cheddar, Swiss, edam, parmesan; cottage cheese; cream cheese; pasteurized processed cheese; cheese spreads.
Avoid: Any cheese product containing oat gum if oat sensitive, some veined cheeses (bleu, stilton, roquefort, gorgonzola).

Potato or Other Starch
Allowed: White and sweet potatoes, yams, hominy, rice, wild rice, gluten-free noodles, some oriental rice and bean thread noodles.
Avoid: Regular noodles, spaghetti, macaroni, most packaged rice mixes, seminola, spinach noodles, frozen potato products with wheat flour added.

Cereals
Allowed: Hot cereals made from cornmeal or other corn-based cereal, Cream of Rice, hominy, rice; Puffed Rice, cereals made without malt.
Avoid: All cereals containing wheat, rye, oats, or barley; bran; graham; wheat germ; durum;  bulgar;

Breads
Allowed: Specially prepared breads using only allowed flours.
Avoid: All breads containing wheat, rye, oat, or barley flours and grains listed above.

Flours and Thickening Agents
Allowed: Arrowroot starch, corn bran, corn flour, corn germ, cornmeal, corn starch, potato flour, potato starch flour, rice bran, rice flour, rice polish, rice starch, soy flour, tapioca starch, bean and lentil flours, nut flours.
Avoid: wheat germ, bran, wheat starch; all flours containing wheat, rye, oats, or barley; spelt; or any grains or cereals listed earlier.

Vegetables
Allowed: All plain, fresh, frozen, or canned vegetables; dried peas and beans; lentils; some commercially prepared vegetables.
Avoid: Creamed vegetables, vegetables canned in sauce, some canned baked beans, commercially prepared vegetables and salads.

Fruits
Allowed: All fresh, frozen, canned, or dried fruits; all fruit juices; some canned pie fillings.
Avoid: Thickened or prepared fruits; some pie fillings; raisins and dried dates that have been dusted with flour.

Fats
Allowed: Butter, ghee, vegetable oil, nuts, peanut butter, hydrogenated vegetable oils (not desirable), some salad dressings, mayonnaise, nonstick cooking sprays.
Avoid: Some commercial salad dressings, wheat germ oil, nondairy cream substitutes, most commercial gravies and sauces.

Soups
Allowed: Homemade broth and soups made with allowed ingredients, some commercially canned soups, specialty dry soup mixes.
Avoid: Most canned soups and soup mixes, bouillon and bouillon cubes with hydrolyzed vegetable protein unless labeled “gluten free”.
Desserts
Allowed: Cakes, quick breads, pastries, and puddings made with allowed ingredients; cornstarch, tapioca, and rice puddings; some pudding mixes; custard; ice cream with few, simple ingredients; sorbet; meringues; mousse; sherbets; frozen yogurt.
Avoid: Commercial cakes, cookies; pies made with wheat, rye, oats, or barley; prepared mixes; puddings; ice cream cones; Jell-O instant pudding; cream fillings; products made with brown rice syrup or malt.  Even organic chocolate bars may be sweetened with malt.

Sweetners
Allowed: Jelly, jam, honey, brown and white sugar, molasses, most syrups, some candy, chocolate, pure cocoa, coconut, marshmallows.
Avoid: Commercial candies dusted with wheat flour, butterscotch chips; flavored syrups; sweets containing malt/malt flavorings; some brown rice syrup; some corn syrup.

Miscellaneous
Allowed: Salt, pepper, herb, herb extracts, food coloring, cloves, allspice, ginger, nutmeg, cinnamon, chili powder, tomato puree and paste, olives, active dry yeast, bicarbonate of soda, baking powder, cream of tartar, dry mustard, some condiments, apple cider, rice or wine vinegar.
Avoid: Curry powder, dry seasonings mixes, gravy extracts, meat sauces, catsup, mustard, horseradish, chip dips, most soy sauce, some distilled white vinegar, instant dry baking yeast, some cinnamon, condiments made with wheat-derived distilled vinegars, communion wafers/bread, some alcohol-based flavoring extracts.

Herbs or supplements that may contain gluten:

Many greens drinks.

Oat straw, milky oats may contain gluten but may not be irritating.

Emergen-C in raspberry and mixed berry flavors only, the other flavors are fine.

Several Chinese herbs are derived from species of wheat and barley and others are traditionally processed using products made from wheat or barley. For example, E jiao and Lu jiao jiao are processed with barley wine, Mai ya is barley sprout and Yi Tang is barley sugar. Fu xiao mai is a type of wheat, and Shen qu, known as “medicated leaven”, is processed with wheat or barley. Other herbs are E. jiao/Equus asinus gelatin, Lu jiao jiao/Cervus nippon antler, Mai ya/Hordeum vulga,Yi tang/Maltose, Fu xiao mai/ Triticum aestivum, Shen qu/Massa fermenta

The following raw herbs and raw herb powders are processed with barley wine and also may contain gluten: Shu di huang/Rehmannia glutinosa root – prepared, Huang jing/Polygonatum sibiricum rhizome, Chuan xiong/Ligusticum chuanxiong (wallichii) rhizome, Rou cong rong/Cistanche deserticola herb, Gui ban jiao/Chinemys reevesii shell – gelatin.

Chinese herbal formulas that contain gluten:

An Mien Pian, An Shui Teapills/An Shui Wan, Bao He San, Bao He Wan, Bojenmi Tea, Bojenmi Teabags, Butiao Tablets/Bu Xue Tiao Jing Wan, Calm Spirit Teapills/ Gan Mai Da Zao Wan, Curing Pills/Kang Ning Wan, Fu Ke Zhong Zi Wan, Gan Mai Da Zao San, Jian Pi Wan, Jiang Ya Pian, Jiao Ai San, Minor Restore The Middle/Xiao Jian Zhong Wan , Qing Zao Jiu Fei San, Rhubarb Teapills/Da Huang Jiang Zhi Wan, Wuchi Paifeng Wan/ Wu Qi Bai Feng Wan, Yang Rong Wan, Yue Ju San, Zhen Gan Xi Feng Teapills, Zi Sheng Wan, Zhi Gan Cao Tang Teapills, Zuo Gu Shen Jing San,