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    Scott Adams

    Research Study on the Establishment of a Safe Gluten Threshold for Celiac Disease Patients

    Celiac.com 01/10/2007 – Celiac disease researchers in Italy and at the Center For Celiac Research in Baltimore, Maryland have conducted a multi center, double-blind, placebo-controlled, randomized trial involving 49 adult individuals who have biopsy-proven celiac disease, and who have been on a gluten-free diet that contains less than 5mg of gluten per day for a minimum of two years. The aim of this study was to determine whether there is a safe threshold for prolonged, daily exposure to minute amounts of gluten. Subjects in the study were divided into 3 groups which were given daily capsules that contained 0mg, 5mg or 50mg of gluten. They were given biopsies and serological screening before and after a gluten challenge. One patient who was given 10mg of gluten daily did experience a clinical relapse, but at the end of the study no significant differences in the IEL count were found between the 3 groups, which lead the researchers to conclude that "(t)he ingestion of contaminating gluten should be kept lower than 50 mg/d in the treatment of celiac disease."

    This study is in line with past gluten threshold studies, and to help you put the amounts of gluten used in the study into perspective, and to demonstrate why the 20 ppm for naturally gluten-free products used in the Codex Alimentarius gluten-free standards is considered to be a safe threshold for those with celiac disease, the following discussion will attempt to quantify just how much gluten it takes to make 50mg.

    The amount of gluten contained in your average 30g slice of wheat bread is around 4.8 grams, or 4,800 milligrams (amount of gluten in wheat bread is normally 10% by weight). If you divide 4,800 by 50 it equals 96, so if divide an ordinary slice of bread into 96 pieces, that is roughly how much daily gluten, according to this study, appears to be safe for those with celiac disease.

    Here is a formula that can be used to determine the number of milligrams of gluten in foods based on the parts per million (ppm) of gluten in the product. The formula is: Products ppm times the number of grams of food divided by 1,000 which equals the number of milligrams. The Codex Alimentarius specifies that naturally gluten-free products contain less than 20ppm, and products that are rendered gluten-free such as Codex quality wheat starch contain less than 200ppm. Using this formula we can determine how many slices of 20ppm and 200ppm gluten-free bread a person with celiac disease would have to eat to consume 50mg of gluten. Here is the math:

    • 20ppm x 30g/1,000 = 0.6 mg. So each slice of 20ppm gluten bread contains 0.6mg of gluten. To get 50mg of gluten per day while eating this type of bread you would have to consume 83.33 slices of it!
    • 200ppm x 30g/1,000 = 6 mg. So each slice of 200ppm gluten bread contains 6mg of gluten. To get 50mg of gluten per day while eating this type of bread you would have to consume 8.33 slices of it.

    The goal of this study (and this article) is not to encourage people with celiac disease to eat gluten. The reality is that cross-contamination of supposedly gluten-free products is very common, and many of us who are on gluten-free diets still unknowingly ingest tiny amounts of gluten on a daily basis. Studies like this can help provide some sense of perspective with regard to how concerned one should be about minute gluten ingestion, and hopefully this article will help you to understand exactly what the 50mg threshold found in the study means. An article called Gluten-phobia in the Winter 2007 issue of Scott-Free Newsletter further addresses what can happen when someone takes their fear of gluten too far and lets it disrupt their life in ways that are so psychologically unhealthy that the negative effects to the author and those around her may actually rival those of the disease itself.

    Here are some links to additional information on this topic:

     

    Comments by Susan Phillips Clavarino:

    I read with interest your remarks about the Catassi/Fasano study. As an active member of the AIC (Association of Italian Celiacs), sponsors of the study, and as the person responsible for revising the language of the text for publication…the study does raise some serious queries about background gluten contamination and its impact on the celiac intestine. When the authors remark that the IELs do not show a difference among the three groups of celiacs on long term gluten free diet (though not compared to the non celiac disease controls), they point out that the villous height/crypt depth ratio is a more valid and more sensitive marker of gluten trace contamination in celiacs on long-term dietary treatment. They also remark that "Despite the restricted criteria adopted in this study, the baseline duodenal biopsy results showed evidence of histologic damage (decreased median Vh/celiac disease count and increased median IEL count in adult celiac disease patients receiving long-term dietary treatment. Furthermore, 4 of 49 subjects had to be excluded from the protocol because severe enteropathy (obscuring the possible effects of the micro challenge) was detected at the baseline evaluation. These results confirm that an abnormal small bowel morphology persists in a significant proportion of celiac disease patients treated with a gluten-free diet, despite full resolution of their symptoms..."(due to)"... the ongoing ingestion of gluten, either deliberate or inadvertent, causing persistent inflammation in the small-intestinal mucosa..." etc.

    As all medically diagnosed Italian celiacs receive a free monthly allowance of naturally (i.e. no wheat starch) gluten free products containing less than 20 ppm from the Italian government health service, and as all the volunteers for the study considered themselves to be healthy (otherwise they would certainly not have volunteered), the finding that 4 out of 49 had to be excluded for severe enteropathy and that histologic damage persists in a significant proportion of adult celiac disease patients on long-term gluten-free diet, besides the other findings of the study (i.e. that 50 mg of gluten per day for only 3 months of trial results in measurable intestinal damage, while there was significant improvement in the placebo group during the strictly monitored trial) is not reassuring. In the light of the Catalan study on the amount of gluten-free dietary foods actually consumed by celiacs in Europe - together with the constant risk of involuntary background contamination and the varying degrees of individual sensitivity - the absolute maximum threshold of ppm in gluten-free products must be kept below 20 ppm. This is a very far cry from the current wording of the Codex Alimentarius which is based on the old standard of the nitrogen content in food.

    I hope that these words may help to clarify the importance of the work done by Profs. Catassi and Fasano, the Association of Italian Celiacs, the study by the Catalan research group (previously cited on your website), and the need for further research and information as to the impact of micro-traces of gluten on celiac disease and its complications so as to ensure that celiacs may make fully informed decisions about their dietary choices.



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    Guest john hardesty

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    I only need 1 part per million and it puts me in the hospital. I just ate a "gluten free" loaf and I'm very sick right now.

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    I have eaten an estimated 4 slices of whole wheat bread (120 grams) daily for several years. Using the 10% figure described above, this is 12 grams/day. Suppose I reduced it to 1 gram/day (a 92% reduction). This is still way more than the 50 mg/day limit described above. If I am gluten sensitive, shouldn't this help a lot?

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  • 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.

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    Jefferson Adams
    Celiac.com 10/07/2008 - Even though nearly 1 out of every 100 people in the world suffers from celiac disease, proper celiac diagnosis can be difficult to diagnose based on symptoms alone, an is often delayed for years. In fact, in the U.S., the average amount of time from first onset of celiac symptoms to a diagnosis for celiac disease is 10 years.
    Currently, the only accepted treatment for celiac disease is a life-long gluten-free diet. However, gluten is present in many processed foods, and many patients with celiac disease are regularly exposed to trace amounts of gluten via contamination and other means.
    One of the challenges of maintaining a life-long diet free of gluten is that so many foods and food products contain gluten. Examples include dried fruit and fruit pie fillings, cold cuts, sandwich spreads, canned meats, many salad dressings and condiments, prepared soups, flavored yogurt, and even flavored instant coffees and herbal teas.
    Following a “strict” gluten-free diet is no guarantee against mucosal damage associated with celiac disease. In two different studies of gluten-free diets, nearly half of the subjects showed villous atrophy. However, the precise level of gluten in each diet was not measured.
    The World Health Organization (WHO) defines naturally gluten-free foods as those with 20 parts of gluten per million (PPM) or less, whereas foods that have been artificially rendered gluten-free must have no more than 200 PPM of gluten. Now, this standard is not universally accepted, in part because of the difficulty of precisely determining the amount of gluten present in different foods. Still, it is obvious that a large number of patients with celiac disease can tolerate foods with minimal amounts of gluten.
    Researchers A. K. Akobeng, and A. G. Thomas recently set out to examine the threshold for gluten consumption among patients with celiac disease by reviewing the results of a number of previous studies.
    In one previous study, researchers examined 4,126 asymptomatic individuals, and found celiac disease in about 1 of 133 of them. The rate for patients with gastrointestinal (GI) symptoms was 1 in 56 subjects. For first-degree relatives of patients with celiac disease, the rate jumped to 1 in 22, while 1 in 39 second-degree relatives tested positive for celiac disease. These figures reflect the existence of a genetic predisposition for the development of celiac disease, as most patients who have celiac disease expressing human leukocyte antigen DQ2 or DQ8 haplotypes.
    One population-based study of 1,612 patients with celiac disease that sheds some light on the demographics and symptoms of the disease shows that nearly three times as many women as men develop celiac disease, while about a third of celiac sufferers had seen 2 or more gastroenterologists. In that study, symptoms persisted for an average of 11 years before a diagnosis of celiac disease.
    Often, such delays are due to the fact that symptoms of celiac disease are similar to many common GI disorders. In addition to the diarrhea experienced by 85% of celiac sufferers, other common symptoms are abdominal pain and distension, Borborygmi, flatulence, and weight loss. Because celiac disease is tied to numerous medical conditions outside of the GI tract, including osteoporosis, iron-deficiency anemia, neuropathy, asthma, and dermatitis herpetiformis, early and accurate diagnosis is important.
    When people with celiac disease eat wheat, rye, or barley, the gluten proteins in these grains sparks inflammation in a part of the small intestine called the lamina propria, which brings about symptoms of the disease.
    In 2007, clinicians proposed new diagnostic guidelines to help doctors diagnose celiac disease more accurately. Under these guidelines, the gliadin antibodies previously used to test for celiac disease have been abandoned because of poor sensitivity and specificity. Serologic testing that focuses on immunoglobulin (Ig)A endomysial antibody, or IgA tissue transglutaminase (tTG) antibody, has been shown to have sensitivity and specificity values above 95% for celiac disease.
    The Review
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    The results of research evaluating consumption of lower levels of gluten have been more uneven. In one study, more than half of subjects consuming only 10 mg of gluten per day experienced worsening of their villous height/crypt ratio. However, another study showed no histologic abnormalities among patients who ingested an average of 34 mg of gluten per day.
    Conclusion
    The current study basically confirms other recent examinations of the limits of gluten consumption in celiac disease, including one study that recommended a daily gluten consumption limit between 10 mg and 100 mg, and another, based on just 83 subjects, that indicated that the mucosa of the small intestine showed no negative long-term changes when subjects consumed up to 80mg of gluten a day.
    While it’s tough to draw specific conclusions from the current study, it seems clear that the standard of 200 PPM or less of gluten in some foods labeled as gluten-free will not protect most celiac disease patients. Instead, the study suggests that a new standard set at a maximum of 20 PPM of gluten will equate to an approximate daily gluten consumption of 6 mg. The body of science suggests that consuming 6mg per day of gluten intake would not promote mucosal abnormalities among most people with celiac disease.
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    Until the results of such research, this review offers a reasonable guideline as the threshold gluten consumption for people with celiac disease.
    References
    1. Lo W, Sano K, Lebwohl B, Diamond B, Green PH. Changing presentation of adult celiac disease. Dig Dis Sci 2003; 48:395-8.
    Aliment Pharmacol Ther. 2008; 27:1044-1052. Epub 2008 February 29.



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    Every celiac is different.  Reactions to gluten are different and so are healing times.  I am one of those who remains ill for months too.    Give it time.  I hope you feel better soon.  
    Sounds awful. My hit me a few days later this time. But I still feel the same three weeks later. Well, a little bit better as my headaches have worn off but I am still so dizzy and have numbness and tingling. It's so hard to concentrate. I feel horrendous but have been to the docs and hosp numerous times and they can't do anything.
    I sorta bump into walls a lot more, misjudge distances and hit my shoulder on door frames in a sort of totter fashion, catch myself almost falling sometimes on stairs, drop stuff, find I lose heat and cold sensitivity and often burn myself, or cut myself. These stick around for a while and slowly taper off. My ataxia normally hits hard the first day within hours of consuming the offending food I can lose full motor control and end up on the floor.
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