A gluten-free diet, recommended in the treatment of celiac disease and autism, is a diet completely free of ingredients derived from gluten-containing cereals: wheat Kamut and spelt, barley, rye, oats and triticale. Although most patients can tolerate oat products, there is a controversy about including them in a gluten-free diet: some medical practitioners say they may be permitted, but the Celiac Society advises against them. Gluten free diets are also beneficial for Chron's disease, and can also help in the treatment of Eczema.
Gluten is a composite of the proteins gliadin and glutenin. These exist, conjoined with starch, in the endosperms of some grass-related grains, notably wheat, rye, and barley. Gliadin and glutenin comprise about 80% of the protein contained in wheat seed. Being insoluble in water, they can be purified by washing away the associated starch. Worldwide, gluten is an important source of nutritional protein, both in foods prepared directly from foods containing it, and as an additive to foods otherwise low in protein.
The seeds of most flowering plants have endosperms with stored protein to nourish embryonic plants during germination, but true gluten, with gliadin and glutenin, is limited to certain members of the grass family. The stored proteins of corn and rice are sometimes called glutens, but their proteins differ importantly from wheat gluten by lacking glutenin. The glutenin in wheat flour gives kneaded dough its elasticity, allowing leavening and contributing chewiness to baked products like bagels.
Adverse reactions to Gluten
Between 0.5 and 1.0 percent of the United States populace is sensitive to gluten. Coeliac disease (or celiac disease, also called gluten sensitive enteropathy (GSE)), is the predominant disorder caused by gluten sensitivity. GSE is an abnormal immune reaction to digestive breakdown products of gliadin. This process damages the lining of the small intestine, which results in chronic malnutrition. Treatment requires a lifelong gluten-free diet and avoiding exposure to air-borne gluten-containing particles such as wheat flour. Gluten allergies and gluten-sensitive idiopathic neuropathies are two other adverse reactions to gluten.
Patients with conditions associated with GSE also benefit from a gluten-free diet and avoiding gluten inhalation. An example of gluten-related skin sensitivity is dermatitis herpetiformis, an intensely itchy skin eruption, which is nearly always accompanied by coeliac disease. This dermatitis usually develops in young adults, predominantly in males; people of North European ethnicity are especially susceptible.
A different, clinical definition of gluten has developed as a result of the determination of wheat gluten as the fraction of wheat that caused coeliac disease. Purification of the gluten proteins first revealed wheat gliadin as the culprit. Proteins from other cereals, even in small amounts, can cause the pathology to persist. Wheat gluten, and the similar proteins within the pure cereals of the grass tribe Triticeae (cultivars are wheats, barleys and ryes) can mediate enteropathy for the majority of affected individuals. These T-cell activating sites are also found in other the Triticeae genera including Aegilops. Therefore, these relatives of wheat are also commonly considered as having gluten.
Studies of the oat gluten avenin have revealed that pathogenic prolamins are either not present, strain specific or weakly stimulatory. For some 2% of celiacs, 'gluten-free' extends to the foods free of oats glutens.
Gluten-free food
Several grains and starch sources are considered acceptable for a gluten-free diet. The most frequently used are maize (corn), potatoes, rice, and tapiocacassava). Other grains and starch sources generally considered suitable for gluten-free diets include amaranth, arrowroot, millet, montina, lupine, quinoa, sorghum (jowar), sweet potato, taro, teff, and yam. Various types of bean, soybean, and nut flours are sometimes used in gluten-free products to add protein and dietary fiber. In spite of its name, buckwheat is not related to wheat; pure buckwheat is considered acceptable for a gluten-free diet, although many commercial buckwheat products are actually mixtures of wheat and buckwheat flours, and thus not acceptable. Gram flour, derived from chickpeas, is also gluten-free. (derived from
People wishing to follow a completely gluten free diet must also take into consideration the ingredients of any over-the-counter or prescription medications and vitamins. Also, cosmetics such as lipstick, lip balms, and chapsticks may contain gluten and need to be investigated before use.
Gluten Cross-Contamination Issues
Special care must be taken when checking ingredients lists as gluten may come in forms such as vegetable proteins and starch, modified food starch (when derived from wheat instead of maize), malt flavoring, and glucose syrup. Many ingredients contain wheat or barley derivatives. Maltodextrin, formerly thought to contain gluten, is generally considered gluten free.
Many foods will contain gluten, but not be indicated on the ingredients, because they are not in the formulation of the product, but in the preparation of it. One example of this is the dusting of the conveyor belts in the production facilities to prevent the foods from sticking during processing. The food itself might not contain gluten, but there is gluten in the ingested product.
Controversy over Oats
The suitability of oats in the gluten-free diet is still somewhat controversial. Some research suggests that oats in themselves are gluten free, but that they are virtually always contaminated by other grains during distribution or processing. However, recent research indicated that a protein naturally found in oats (avenin) possessed peptide sequences closely resembling wheat gluten and caused mucosal inflammation in significant numbers of celiac disease sufferers. Some examination results show that oats are very dangerous to certain celiacs, while not very harmful to others. Given such conflicting results, excluding oats is the only risk free choice for celiac disease sufferers.
The cross-contamination issue with oats, can also be inferred to extend to all other grains that share the same farm, truck, mill, or bagging facility as wheat and other gluten-containing grains. Therefore, removing all flours and grains from the diet may be the only way to guarantee a complete absence of gluten in the diet.
Accuracy of "Gluten-Free" Labels
The legal definition of the phrase "gluten-free" varies from country to country. Current research suggests that for persons with celiac disease the maximum safe level of gluten in a finished product is probably less than 0.02% (200 parts per million) and possibly as little as 0.002% (20 parts per million).
Australian standards reserve the "gluten free" label for foods with less than 5 parts per million of gluten, as this is the smallest amount currently detectable. As gluten-containing grains are processed, more and more of the gluten is removed from them, as shown in this simple processing flow:
Wheat Flour (80,000ppm) > Wheat Starch (200ppm) > Dextrin > Maltodextrin > Glucose Syrup (<5ppm) > Dextrose > Caramel Color
Since ordinary wheat flour contains approximately 12% gluten, even a tiny amount of wheat flour can cross-contaminate a gluten-free product. Therefore, considerable care must be taken to prevent cross-contamination in both commercial and home food preparation.
This diet rules out all ordinary breads, pastas, and many convenience foods. Many countries do not require labelling of gluten containing products, but in several countries (especially Australia and the European Union) new product labelling standards are enforcing the labelling of gluten-containing ingredients. Various gluten-free bakery and pasta products are available from specialty retailers.
Unfortunately, in the United States, the Food and Drug Administration (FDA) has not yet defined the term gluten free as it appears on food labels. It is currently up to the manufacturers of "gluten free" food items to guarantee such a claim. "A final rule that defines the term gluten-free and identifies the criteria that would enable the food industry to use that term" is scheduled to be released by the FDA on August 2nd, 2008. Many so-called gluten free products have been found to have been contaminated with gluten (such as Pamela's cookies, etc.).
The Gluten Free Market
Formerly looked upon as an afterthought in the overall scheme of health issues, today celiac disease (or gluten intolerance) has gone mainstream, affecting an estimated 1 in 133 (or 2.18 million) Americans. What makes the disorder so difficult to deal with is that there is no known cure; the only treatment currently available is complete and total abstinence from products containing gluten. This is a difficult task, as there are many hidden sources of gluten existing in the ingredients of many processed foods.
Because of the sheer size of the gluten-sensitive audience, manufacturers and retailers have become aware of their needs and have begun to offer products addressing the problem. According to ACNielsen LabelTrends data, nearly $400 million was generated at retail (mass, club, grocery, excluding Wal-Mart) by products bannered as "gluten-free" for the 52-week period ending October 8, 2005. That represented a 6.2 percent increase in retail dollars, which followed a 16.9 percent increase the previous year. Furthermore, 325 new "gluten-free" products were introduced over the past year, raising the total number of UPCs to 1,220.
In response to the growing market, many grocers have gone beyond simply carrying gluten-free products and are introducing shelves and entire sections of gluten-free items. Take Hannaford Bros., for instance. The Portland, Maine-based grocery chain with 140 stores serving northern New England, upstate New York, Virginia and the Carolinas, has recently added gluten-free sections to its format.
Wegmans Food Market is another grocery chain that has taken the proactive approach to marketing gluten-free food products. In fact, the Rochester, N.Y.-based chain was substantially ahead of the curve. In 1985, Wegmans created "Gluten Sensitivity, Making a Special Diet Easier to Swallow," a booklet for their shoppers. Today, it includes a complete list of branded products it carries on the company's web site. In addition, in the late '90s, Wegmans launched a "Wellness Key" initiative in which all gluten-free store-brand products were labeled with a "G" for easy identification.
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