Wheat, like both barley and rye, contains a type of protein called gluten. Approximately 80 per cent of the protein in wheat is gluten, which is called gliadin. People with coeliac disease--which is an autoimmune disease--must eat a gluten-free diet because their intolerance to the protein causes their immune system to attack the lining in their gut. A large number of products on grocery store shelves contain wheat, and it can be a challenge to know which foods are safe.
All fresh fruits and vegetables are wheat and gluten-free, making the produce area a safe zone in any supermarket. Dried fruit is another safe product. Frozen fruits and vegetables with nothing added are virtually the same as fresh products. Frozen produce that has additional flavouring or sauce packets most likely has wheat in it, since many natural and artificial flavours use it as an ingredient. Canned fruits and vegetables are also all right as long as there are no other ingredients. Along the same lines, only 100 per cent fruit juice is safe, as any additives may contain wheat.
Meat and Fish
Fresh fish, seafood, poultry, beef and pork do not contain wheat or other types of gluten. The same is true of canned tuna and canned chicken. Frozen cuts of meat and fish with no additional flavouring is safe to consume, but stay away from breaded fish and poultry or pork that comes with a premade baste or sauce. Eggs are on the list, but deli meat is not; it is a source of wheat gluten, via additives, and should be avoided. Imitation seafood and bacon contains wheat as well.
Most dairy products are harmless for those needing to avoid gluten, however, there are some exceptions. The safe list includes sour cream, cream cheese, cottage cheese, butter and margarine, cream, milk, many yoghurts and aged cheeses. Processed cheese often contains wheat-based additives or is processed in a facility that also handles wheat, meaning there's a danger of cross-contamination. Avoid flavoured milk as well, for the same reason that flavouring may contain a wheat product. The flavouring in some yoghurt can be problematic as well.
Grains and Starches
There are several grain alternatives to wheat. The most commonly available include plain rice, quinoa, amaranth, buckwheat and millet. Other safe flours and starches are potato flour and starch, corn, arrowroot, flax, flour from seeds, nuts or beans, sorghum and tapioca. Grits, puffed rice and cream of rice are on the list of safe cereals, and corn tacos and tortillas are also acceptable. Rice cakes and rice crackers are acceptable snacks, as are tortilla chips and popcorn.
The list of wheat-free food is actually quite long, despite the fact that wheat pervades so many food products. Commonly consumed foods that are free of wheat include vegetable and olive oils, nuts, seeds, lentils, honey, peanut butter, jam, tofu, unflavored crisps, olives, pickles, sugar, coffee, tea and even carbonated beverages.