Jump to content

Important Information

This site places cookies on your device (Cookie settings). Continued use is acceptance of our Terms of Use, and Privacy Policy.

  • Sign Up
  • Join our community!

    Do you have questions about celiac disease or the gluten-free diet?

  • Member Statistics

    84,913
    Total Members
    4,125
    Most Online
    TMT
    Newest Member
    TMT
    Joined
  • 0

    What is gluten? What is gliadin?


    Scott Adams

    Traditionally, gluten is defined as a cohesive, elastic protein that is left behind after starch is washed away from a wheat flour dough. Only wheat is considered to have true gluten. Gluten is actually made up of many different proteins.

    There are two main groups of proteins in gluten, called the gliadins and the glutenins. Upon digestion, the gluten proteins break down into smaller units, called peptides (also, polypeptides or peptide chains) that are made up of strings of amino acids--almost like beads on a string. The parent proteins have polypeptide chains that include hundreds of amino acids. One particular peptide has been shown to be harmful to celiac patients when instilled directly into the small intestine of several patients. This peptide includes 19 amino acids strung together in a specific sequence. Although the likelihood that this particular peptide is harmful is strong, other peptides may be harmful, as well, including some derived from the glutenin fraction.

    It is certain that there are polypeptide chains in rye and barley proteins that are similar to the ones found in wheat. Oat proteins have similar, but slightly different polypeptide chains and may or may not be harmful to celiac patients. There is scientific evidence supporting both possibilities.

    When celiac patients talk about "gluten-free" or a "gluten-free diet," they are actually talking about food or a diet free of the harmful peptides from wheat, rye, barley, and (possibly) oats. This means eliminating virtually all foods made from these grains (e. g., food starch when it is prepared from wheat, and malt when it comes from barley) regardless of whether these foods contain gluten in the very strict sense. Thus, "gluten-free" has become shorthand for "foods that dont harm celiacs."

    In recent years, especially among non-celiacs, the term gluten has been stretched to include corn proteins (corn gluten) and there is a glutinous rice, although in the latter case, glutinous refers to the stickiness of the rice rather than to its containing gluten. As far as we know, neither corn nor glutinous rice cause any harm to celiacs.

    0


    User Feedback

    Recommended Comments



    Guest abdelfattah

    Posted

    Good subject, I have learned many thing from this article.

    Share this comment


    Link to comment
    Share on other sites
    Guest MARILYN BEAVERS

    Posted

    I FOUND THIS TO BE VERY INFORMATIVE

    Share this comment


    Link to comment
    Share on other sites
    Guest Colette

    Posted

    Thanks for this. I was tring to work out whether TicTacs were gluten free and the FAQ said something about corn gluten - which mystified me!

    Share this comment


    Link to comment
    Share on other sites
    Guest Vitamin D girl

    Posted

    Just what I was looking for! I was trying to figure out how gliadin relates to gluten.

    Share this comment


    Link to comment
    Share on other sites
    Guest Lynda Bradley

    Posted

    Explains what gliadin is that my client is allergic to.

    Share this comment


    Link to comment
    Share on other sites

    Thanks, still being used 4+ years after the first comment.

    Share this comment


    Link to comment
    Share on other sites
    Guest elaine ester

    Posted

    I sent this information to 3 different states. Thank you and keep it coming. Now I need some gluten-free meal plans and recipes.

    Share this comment


    Link to comment
    Share on other sites
    Guest Mims Haske

    Posted

    Very informative. I'm looking for ways to increase my knowledge base while decreasing my waistline. This has been a helpful starting point. Plus I'll pass it on to a friend! :)

    Share this comment


    Link to comment
    Share on other sites



    Your content will need to be approved by a moderator

    Guest
    You are commenting as a guest. If you have an account, please sign in.
    Add a comment...

    ×   Pasted as rich text.   Paste as plain text instead

      Only 75 emoji are allowed.

    ×   Your link has been automatically embedded.   Display as a link instead

    ×   Your previous content has been restored.   Clear editor

    ×   You cannot paste images directly. Upload or insert images from URL.


  • About Me

    In 1994 I was diagnosed with celiac disease, which led me to create Celiac.com in 1995. I created this site for a single purpose: To help as many people as possible with celiac disease get diagnosed so they can begin to live happy, healthy gluten-free lives. Celiac.com was the first site on the Internet dedicated solely to celiac disease. In 1998 I founded The Gluten-Free Mall, Your Special Diet Superstore!, and I am the co-author of the book Cereal Killers, and founder and publisher of Journal of Gluten Sensitivity.

  • Related Articles

    Scott Adams
    Celiac disease (also called coeliac, nontropical sprue, celiac sprue, gluten intolerant enteropathy, or gluten sensitive enteropathy) is a condition in which there is a chronic reaction to certain protein chains, commonly referred to as glutens, found in some cereal grains. This reaction causes destruction of the villi in the small intestine, with resulting malabsorption of nutrients.
    There is clear evidence of a family tendency toward celiac disease. 5-10% of the first-level relatives (parents, children, and siblings) of diagnosed celiacs may develop celiac disease. The disease affects both sexes, and it can begin at any age, from infancy (as soon as cereal grains are introduced) to later life (even though the individual has consumed cereal grains all along). The onset of the disease seems to require two components: genetic predisposition (two specific genetic markers, called HLA sub-factors, are present in well over 90% of all celiacs in America), and some kind of trigger. The trigger may be environmental (as in overexposure to wheat), situational (perhaps severe emotional stress), physical (such as a pregnancy, an operation), or pathological (a viral infection).
    Once thought to be a childhood disease that would be outgrown, recent evidence indicates that it is not uncommon for the symptoms of celiac disease to disappear during late childhood or adolescence, giving the appearance of a cure. Unfortunately, damage still occurs during these years of apparent health, and later in life these celiacs may find they have suffered considerable damage to the small intestine, and have for years deprived themselves of important nutrients.

    Scott Adams
    No. Celiac sprue is not a well-researched disease. Most of what we know about foods that are safe and foods that are not is gathered from anecdotal evidence provided by celiacs themselves. There is a great deal of controversy about what affects celiacs and what doesnt.
    Take, for example, buckwheat. Along with corn and rice, this is one of only three common grains left on the "safe" list for celiacs. However, some celiac societies have put it on the "unsafe" list and there is anecdotal evidence that some individuals react to it as they do to wheat. Yet a well-known specialist in grain research points out that buckwheat is more closely related to rhubarb than to the toxic grains, so if buckwheat is unsafe then any plant might be unsafe.
    In considering anecdotal evidence for whether a food is safe or not, individuals must make their own choices, but each of us should clearly understand that anecdotal evidence is gathered from individuals with widely varied experience.
    It could be that the "buckwheat flour" that a celiac reacted to was actually one of those mixes that combines buckwheat flour with wheat flour. Another possibility is that, since buckwheat and wheat are often grown in the same fields in alternating years, the "pure buckwheat flour" may have been contaminated from the start by wheat grains gathered at harvest. Yet another explanation might be that the buckwheat was milled in a run that was preceded by wheat or any of the other toxic grains, so the flour was contaminated at the mill. Finally, some individuals -- celiacs or not -- may have celiac-like reactions to buckwheat; they are allergic. Celiacs who are allergic to buckwheat may be easily fooled into believing they are having a gluten reaction. Or, it could be that some evolutionary trick has put a toxic peptide chain into buckwheat despite its distant relation to the other grains, but the odds against this happening are long.
    As individual celiacs learn to live gluten-free, they must gauge their own reactions to foods, do lots of research, ask questions, and try to understand the many variables that may affect the ingredients in their food.
    The following is a list of ingredients which some celiacs believe are harmful, others feel are safe:
    Alcohol Grain alcohol Grain vinegars White vinegar Vanilla extract and other flavorings (may contain alcohol) Amaranth Millet Buckwheat Quinoa Teff   Wheat starch is used in the some countries gluten-free diet because of the belief that it contains only a trace or no gluten and that good baked products cannot be made without it. In a laboratory, wheat starch purity can be easily controlled, but in most plants this is not always the case. Wheat starch is not considered safe for celiacs in these countries: United States, Canada, Italy.
    For more information on this topic visit our Safe & Forbidden Lists.

    Scott Adams
    Vijay Kumar, M.D., Research Associate Professor at the University of Buffalo and President and Director of IMMCO Diagnostics: Convincing the doctor initially depends upon the patient. However, the laboratory to which the test is sent should be available to answer questions the doctor may have. Our laboratory always encourages such questions.
    Karoly Horvath, M.D., Ph.D., Associate Professor of Pediatrics; Director, Peds GI & Nutrition Laboratory; University of Maryland at Baltimore: Lot of physicians in the USA did not get appropriate training to recognize the protean manifestations of celiac disease. However, if the classical symptoms are present--chronic diarrhea, weight loss, protuberant abdomen, foul-smelling stools, etc.--it is absolutely indicated to test the patients serum for antigliadin and antiendomysium antibodies.
    Professionals participating in this discussion group are educating physicians on an almost daily basis. Generally, it is useful to supply the physician with a review article or a textbook chapter describing the values of serological tests and protean manifestations of celiac disease. If that does not help, you can ask the help of professionals participating in the Cel-Pro list. They have helped several patients by calling physicians and convincing them about the necessity of serological testing.

    Scott Adams
    Vijay Kumar, M.D., Research Associate Professor at the University of Buffalo and President and Director of IMMCO Diagnostics: The biopsy may be inconclusive. Serum, if tested for gliadin, endomysial and reticulin antibodies, should provide unequivocal information. Ours and other studies have provided a strong reliability of the serum tests.
    Karoly Horvath, M.D., Ph.D., Associate Professor of Pediatrics; Director, Peds GI & Nutrition Laboratory; University of Maryland at Baltimore: The biopsy may be inconclusive in a small percentage of patients with so-called patchy lesions in the duodenum. It means that there are histologically normal looking spots with finger like villi and pathologic spots showing flattened mucosa in the upper half of the duodenum. If celiac disease is suspected, the gastroenterologist should obtain several biopsies from different spots of the whole duodenum. Most of the endoscopists routinely examine only the upper half of the duodenum (duodenal bulb and the descending part). The transverse segment of the duodenum is not viewed routinely. Few endoscopic centers have an enteroscope, which is a longer and more flexible endoscope for examining the entire duodenum and jejunum. The enteroscopy allows you to obtain biopsies even from the jejunum. The histological examination of a single biopsy specimen may increases the risk of false negative diagnosis.
    The experience of the pathologist in the interpretation of small intestinal histology is important. In centers specializing in celiac disease the gastroenterologist routinely reviews the histologic slides together with the pathologist. There is still a possibility of inconclusive results if multiple biopsies are obtained and the histological interpretation is appropriate. All disease has a developmental process. It means that it takes time for the pathological changes to be evident. There are cases when the symptoms suggest celiac disease, however, the histology is not conclusive. This problem occurs in only a few cases. A repeated biopsy may be necessary after a period of higher gluten intake. However, if the antiendomysium antibody test is positive and the histology is not conclusive a gluten-free diet is recommended.
    The serology test may be inconclusive if:
    The sample handling and shipping is inappropriate; e.g. the serum was shipped at room temperature for days The patient has IgA deficiency, which occurs in one out of 600 people in the general population and much more frequently in patients with celiac disease. In these cases the antigliadin IgA and the antiendomysium IgA tests give negative results. If the tests are performed in a laboratory specialized in celiac serological tests, the laboratory recommends a test for immunoglobulins. If a patient has IgA deficiency and positive antigliadin IgG test, he/she should undergo further absorptive tests and/or an intestinal biopsy.

  • Popular Contributors

×