- Gluten-free diet
A gluten-free diet is recommended amongst other things in the treatment of
coeliac diseaseand wheat allergy. It is a diet completely free of ingredients derived from gluten-containing cereals: wheat(including kamutand spelt), barley, rye, and triticale, as well as the use of gluten as a food additivein the form of a flavoring, stabilizing or thickening agent. Additionally, the diet may exclude oats. Some people for whom the diet is recommended can tolerate oatproducts and some medical practitioners say they may be permitted, [cite web|url=http://pmj.bmj.com/cgi/content/abstract/82/972/672|title=Coeliac disease and oats: a systematic review|publisher=The Fellowship of Postgraduate Medicine|author=N Y Haboubi, S Taylor, S Jones|year=2006] but there is controversy about including them in a gluten-free diet because studies on the subject are incomplete. [ [http://www.celiacsociety.com/celiacinfo_diet.asp "The Gluten-Free Diet" - CeliacSociety.com] ]
Although gluten is commonly associated with wheat, not all wheat products contain gluten. For instance highly processed wheat glucose has been found to contain no detectable gluten (ie less than 5 parts per million gluten).Fact|date=August 2008
Several grains and
starchsources are considered acceptable for a gluten-free diet. The most frequently used are maize, potatoes, rice, and tapioca(derived from cassava). 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, chia seed, and yam. Various types of bean, soybean, and nut flours are sometimes used in gluten-free products to add proteinand dietary fiber. In spite of its name, buckwheatis 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.
Gluten is also used in foods in some unexpected ways, for example as a stabilizing agent or thickener in products like
ice-creamand ketchup[cite web|url=http://www.ext.colostate.edu/pubs/columnnn/nn030331.html|title=Gluten sensitivity more widespread than previously thought|publisher=Colorado State University Extension|author=Pat Kendall, Ph.D., R.D.|date= March 31, 2003] [cite web|url=http://bidmc.harvard.edu/default.asp?leaf_id=12799|title=Following a Gluten-free Diet|publisher=Beth Israel Deaconess Medical Center|author= |date= A Harvard teaching hospital]
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 lip gloss may contain gluten and need to be investigated before use.
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. [http://glutenfreeliving.com/ingredients.html]
Many foods contain gluten, but do not indicate it in their ingredients list, because they are not in the formulation of the product, but in the preparation (or manufacturing) of some of the listed ingredients. 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 [cite web
title=The Molecular Basis for Oat Intolerance in Patients with Celiac Disease
coauthors=Burkhard Fleckenstein; Øyvind Molberg; Helge Scott; Frits Koning; Günther Jung; Peter Roepstorff; Knut E. A. Lundin; Ludvig M. Sollid
accessdate=2006-07-22] 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 even oats, which are not contaminated with wheat particles, are nonetheless dangerous to about 10 percent of celiacs, while not very harmful to the majority. Such oats are generally considered risky for celiac children to eat, but two studies show that they are completely safe for celiac adults to eat, [cite web
title=Adult coeliac patients do tolerate large amounts of oats
publisher=European Journal of Clinical Nutrition
coauthors=M Olsson; R Avidsson Lenner; L Å Nilsson; O Nilsson; A Kilander
accessdate=2008-08-14] even over a period of five years. [cite web
title=No harm from five year ingestion of oats in coeliac disease
publisher=GUT Journal Online
coauthors=T A Kemppainen; R J K Julkunen; V-M Kosma; M Mäki; M Heikkinen; M I J Uusitupa
accessdate=2008-08-14] Given this conflicting information, excluding oats appears to be the only risk free practice for celiac disease sufferers of all ages.cite web|url=http://www.csaceliacs.org/InfoonOats.php|title=The Scoop on Oats|publisher= [Celiac Sprue Association (CSA)|date=
February 20, 2008] However, medically approved guidelines exist for those celiacs who do wish to introduce oats into their diet. [cite web
title=Guidelines for Consumption of Pure and Uncontaminated Oats by Individuals with Celiac Disease
publisher=Professional Advisory Board of Canadian Celiac Association
Unless manufactured in a dedicated facility and under gluten-free practices, all cereal grains, including oats, can be cross-contaminated with gluten. Grains become contaminated with gluten by sharing 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
Codex Alimentarius" set of international standards for food labelling has a standard relating to the labelling of products as "gluten free", however this standard does not apply to "foods which in their normal form do not contain gluten". [cite web|url=http://www.codexalimentarius.net/download/standards/291/CXS_118e.pdf|publisher= Codex Alimentarius|title=Codex Standard For "Gluten-Free Foods" CODEX STAN 118-1981|date= February 22, 2006|format=PDF]
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:
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; it also excludes gravies, custards, soups and sauces thickened with wheat, rye, barley or other gluten-containing flour. Many countries do not require labelling of gluten containing products, but in several countries (especially Australiaand 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 speciality retailers.
In the United States, gluten may not be listed on the labels of certain foods because the U.S.
Food and Drug Administrationhas classified gluten as GRAS ( Generally recognized as safe). [cite web|url=http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=184.1322|title= Sec. 184.1322 Wheat gluten|publisher= Code of Federal Regulations Center|author= |date= April 1, 2007] Requirements for proper labelling are being formulated by the USDA. 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 [cite web
last = Kane
first = Rhonda
title = Public Meeting On: Gluten-Free Food Labeling
publisher = U.S. FDA
url = http://www.cfsan.fda.gov/~dms/glutran.html
August 19, 2005
accessdate = 2007-03-27] . Many so-called gluten free products have been found to have been contaminated with gluten (such as chicken bouillon, corn cereal, caramel ice cream topping, [cite web
last = Schorr
first = Melissa
title=Study: Wheat-Free Foods May Contain Wheat
url = http://www.geocities.com/HotSprings/Spa/4003/gf-contaminated.html
March 22, 2004
accessdate = 2008-08-14] and Pamela's cookies [cite web|title=Contaminated|publisher = Celiac Disease On-Line Support Group
February 7, 2002
accessdate = 2007-03-27] , etc.).
United Kingdom, only cereals currently need to be labelled, while other products are voluntary. [cite web|url=http://www.food.gov.uk/multimedia/pdfs/labelamendguid21nov05.pdf|month=November | year=2005|title=Guidance Notes on the Food Labelling (Amendment)(No. 2) Regulations 2004|publisher= Food Standards Agency|format=PDF] For example, sausages commonly contain Butcher's Rusk, a grain-derived food additive. [cite web|url=http://www.food.gov.uk/multimedia/pdfs/meatproductguidancescot.pdf|title=Labelling and Composition of Meat Products|publisher= Food Standards Agency|date= April 22, 2004|accessdate=2008-02-23|format=PDF] Furthermore, while UK companies selling food prepared on their own premises are given guidance by the Food Standards Agency, they are not required to meet any labeling requirements. [cite news|url=http://news.bbc.co.uk/2/hi/uk_news/7191651.stm|title=Food allergy guidance published|date= January 16, 2008|accessdate=2008-02-24|publisher= BBC News]
Lastly, some non-foodstuffs such as
medications and vitaminsupplements, especially those in tabletform, may contain gluten as an excipientor binding agent. [cite web|url=http://www.ipecamericas.org/public/faqs.html#question4|title=Frequently Asked Questions|publisher= [http://www.ipecamericas.org/ IPC Americas Inc] |date=2008-02-27|accessdate=2008-04-15] [cite web|url=http://www.glutenfreedrugs.com/Excipients.htm|title=Excipient Ingredients in Medications|date= November 3, 2007|accessdate=2008-04-15|publisher= [http://www.glutenfreedrugs.com Gluten Free Drugs] ] People with gluten intolerances may therefore require specialist compoundingof their medication.
Most specialistsWho|date=February 2008 now consider all distilled forms of alcohol safe to drink, provided no colourings or other additives have been added as these ingredients may contain gluten. Although Straight Bourbon is made from
maizeand wheat, ryeor barley, the gluten in these grains is removed by the process of distillation. Whiskeyon the other hand will likely contain gluten as the malted barleyor rye is often added after the grain mash has been distilled. Spirits made without any grain such as wine, sherry, port, cider, rum, tequilaand vermouthdo not contain gluten. Liqueurs and pre-mixed drinks should be examined carefully for gluten-derived ingredients.
Almost all beers are brewed with malted
barleyor wheatand will contain gluten. Sorghumand buckwheat-based gluten-free beers are available, but remain very much a specialty product. Some low-gluten beers are also available, however there is disagreement over the use of gluten products in brewed beverages: Some brewers argue that the proteins from such grains as barleyor wheatare converted into amino acids during the brewingprocess and are therefore gluten-free, [cite web
year = 2006
url = http://www.celiac.com/st_prod.html?p_prodid=413
title = Is Beer Gluten-Free and Safe for People with Celiac Disease?
publisher = Celiac.com ] however there is evidence that this claim is false. [cite web
Australian barley technical Symposium
year = 2001
url = http://www.regional.org.au/au/abts/1999/sheehan.htm
title = Improved Methods for Determination of Beer Haze Protein Derived from Malt
publisher = Marian Sheehan A, Evan Evans B, and John Skerritt ]
The gluten-free diet must be strictly followed by sufferers of
coeliac disease[cite web
month=October | year=2005
National Digestive Diseases Information Clearinghouse, USA
dermatitis herpetiformis. [cite web
title=Medical Encyclopedia - Dermatitis herpetiformis
National Library of Medicine, USA
The scientific literature on the link between gluten and autism is mixed and there is no substantial research on in utero causality. There have been too few adequately designed, large-scale controlled studies and
clinical trials to state whether the diet is effective. [cite journal |author= Millward C, Ferriter M, Calver S, Connell-Jones G |title= Gluten- and casein-free diets for autistic spectrum disorder |journal= Cochrane Database Syst Rev |year=2008 |issue=2 |pages=CD003498 |doi=10.1002/14651858.CD003498.pub3 |pmid=18425890] A small single blind study has documented fewer autistic behaviors in children fed a gluten-free, casein-free diet, but noted no change in cognitive skills, linguistic ability, or motor ability. [cite journal |journal= Nutr Neurosci |year=2002 |volume=5 |issue=4 |pages=251–61 |title= A randomised, controlled study of dietary intervention in autistic syndromes |author= Knivsberg AM, Reichelt KL, Høien T, Nødland M |doi=10.1080/10284150290028945 |pmid=12168688] This study has been criticized for its small sample size, single-blind design which may have skewed results on the basis of a "parent placeboeffect". [cite journal |journal= J Dev Behav Pediatr |year=2006 |volume=27 |issue=2 Suppl 2| pages=S162–71 |title= Elimination diets in autism spectrum disorders: any wheat amidst the chaff? |author= Christison GW, Ivany K |pmid=16685183 |doi= 10.1097/00004703-200604002-00015] A 2006 double-blind short-term study found no significant differences in behavior between children on a gluten-free, casein-free diet and those on regular diets.cite journal |journal= J Autism Dev Disord |year=2006 |volume=36 |issue=3 |pages=413–20 |title= The gluten-free, casein-free diet in autism: results of a preliminary double blind clinical trial |author= Elder JH, Shankar M, Shuster J, Theriaque D, Burns S, Sherrill L |doi=10.1007/s10803-006-0079-0 |pmid=16555138] A long term double-blind clinical trial sponsored by the National Institute of Mental Healthis scheduled for completion in April 2008; preliminary results are not yet available. Fact|date=September 2008
Gluten-free, casein-free diet
* Glutamic acid
Wheat gluten (food)
Specific Carbohydrate Diet
* [http://www.celiaccenter.org/ Center For Celiac Research]
* [http://www.celiacawareness.org/ National Foundation for Celiac Awareness]
* [http://www.aafp.org/afp/980301ap/pruessn.html Detecting Celiac Disease in Your Patients]
* [http://www.celiac.nih.gov NIH Celiac Disease Awareness Campaign]
* [http://www.celiac.com/articles/182/1/Unsafe-Gluten-Free-Food-List-Unsafe-Ingredients/Page1.html Unsafe Food and Ingredients List]
* [http://www.glutenfreelifestyle.com.au/ Gluten Free Information - Educational Video Series]
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