(Celiac.com 06/12/2000) I work for a company that supplies computerized control equipment to the grain handling industry. I have been in grain elevators across Canada and the US. I have limited experience with flour mills. Virtually all grains and bean crops are contaminated, their is little economic incentive for the elevators to fix this problem as most often a small amount of a less expensive crop is contaminating a more expensive one. I have even seen elevators intentionally contaminate certain high price commodities (i.e. bean crops), though to be fair most of this is removed by cleaning equipment at the mills. And if the allowable limits are exceeded the train-car or transport-truck will be rejected by the mill and sent back to the elevator at a considerable expense. Since all grains are moved by the same equipment and this metal equipment is forever wearing out allowing small amounts of amounts of grain to spill into the holding area for another. Also the same equipment is used to move different grains, it is possible for a truck carrying one grain to dump into the same elevating equipment that was just used to carry another, a certain amount of residue is left in even the most well maintained equipment.

As someone with mild wheat intolerance (I have never been tested for celiac), I do not worry about this. The intolerance is not an allergic reaction, the miniscule amounts of gluten I would encounter from this sort of thing is miniscule, and I have never had a symptomatic reaction to any oat product. But I am forever reacting to restaurant food that has been dusted with flour, or potato soups that have been thickened with flour. My worst experience is when I was served cream-of-wheat as oatmeal.

The only plants demonstrated to have proteins that damage the small intestines of people with celiac disease are those from wheat, rye, and barley (and the man-made wheat-rye cross called triticale). Although oats had generally been considered harmful until 1996, several high quality studies published since then indicate that oats are not harmful either in celiac disease or dermatitis herpetiformis. Some physicians choose not to accept these findings or else point out that there is some potential problem of contamination of oats by wheat. The contamination question has not yet been adequately researched, but may be overemphasized. The three harmful species are members of the grass family and are quite closely related to one another according to various schemes of plant classification (taxonomy). However, not all members of the grass family damage the intestines of celiac patients. Rice and corn, for example, are apparently harmless.

Many other grains have not been subjected to controlled testing or to the same scrutiny as wheat, rye, barley, oats, rice, and corn in relation to celiac disease. In fact, only wheat and oats have been extensively studied in controlled experiments with the most up-to-date methods. If we accept corn and rice as safe, however, and this seems reasonable to me, then members of the grass family that are more closely related to these species (on the basis of taxonomy) than to wheat are likely to be safe. Such grasses include sorghum, millet, teff, ragi, and Jobs tears, which appear to be reasonably closely related to corn. In some cases, there are protein studies in support of this conclusion, although the studies are not sufficiently complete to provide more than guidance. Scientifically controlled feeding studies with celiac patients would provide a better answer. However, such studies are not likely to be carried out in the next few years because of high costs and the difficulty of obtaining patient participation (such studies would likely involve intestinal biopsy). In lieu of feeding studies, further studies of protein (and DNA) would provide the next best way to evaluate my suggestion that millet, sorghum, teff, ragi, and Jobs tears are not likely to be toxic in celiac disease, although even such studies are hampered at present by a lack of knowledge of which sequences in the wheat gluten proteins are harmful. There is evidence that a few sequences are harmful, but not all possibilities have yet been tested.

The scientific name for bread wheat is Triticum aestivum var. aestivum--the first part of the name defines the genus (Triticum) and the second part, the species (aestivum). Species falling in the genus Triticum are almost certain to be harmful to celiac patients. Grain proteins of these species include the various types characteristic of the gluten proteins found in bread wheats (including the alpha-gliadins) that cause damage to the small intestine in celiac disease. Durum wheats (Triticum turgidum var. durum) used for pasta are also harmful to celiac patients. Some Triticum species of current concern include Triticum aestivum var. spelta (common names include spelt or spelta), Triticum turgidum var. polonicum (common names include Polish wheat, and, recently, Kamut), and Triticum monococcum var. monococcum (common names include einkorn and small spelt). I recommend that celiac patients avoid grain from these species. Also, given their very close relationship to bread and durum wheats, I think it is unlikely that these grains would be safe for those with classical allergic responses to wheat.

Rye (Secale cereale) and barley (Hordeum vulgare) are toxic in celiac disease even though these two species are less closely related to bread wheat than spelta and Kamut. They belong to different genera, Secale and Hordeum, respectively, and lack alpha-gliadins, which may be an especially toxic fraction.

There have been anecdotal reports suggesting a lack of toxicity in celiac disease for spelta and Kamut, along with anecdotal reports of the opposite, at least in the case of spelt-celiac patients who have been harmed by eating it. Controlled tests would be necessary to draw a firm conclusion, although they hardly seem necessary insofar as spelt and Kamut should be considered forms of wheat.

The diagnosis, sometimes self-diagnosis, of celiac disease is occasionally made without benefit of reasonably rigorous medical or clinical tests, especially intestinal biopsy. Individuals who are diagnosed in this way without rigorous testing may not actually have celiac disease. Claims that particular foods cause this latter group no problems in relation to their celiac disease could cause confusion.

Furthermore, celiac patients who report no problems in the short run with spelt or Kamut might experience relapse later. There is now adequate evidence that when celiac patients on a gluten-free diet (that is, a diet free of any proteins or peptides from wheat, rye, and barley) have wheat reintroduced to their diets, times-to-relapse vary enormously among individuals, ranging from hours to months, or even years. And this is for wheat, presumably the most toxic of all cereal grains to celiac patients.

Additionally, the relapse may not be accompanied by obvious symptoms, but be recognized only by physicians through observation of characteristic changes in the small intestinal tissues obtained by biopsy. The reasons for the enormous variability of response times are not known. It may be speculated that the variability has something to do with the degree of recovery of the lining of the small intestine on a gluten-free diet, the degree of stress that the patient had been experiencing (including infections), and individual genetic differences.

As I have indicated, all known grain species that cause problems for celiac patients are members of the grass family. In plant taxonomy, the grass family belongs to the Plant Kingdom Subclass known as monocotyledonous plants (monocots). The only other grouping at the Subclass level is that of dicotyledonous plants (dicots). Some other species about which celiac patients have questions actually are dicots, which places them in very distant relationship to the grass family. Such species include buckwheat, amaranth, quinoa, and rape. The seed of the last plant listed, rape, is not eaten, but an oil is pressed from the seeds that is commonly used in cooking. This oil is being marketed as canola oil. Because of their very distant relationship to the grass family and to wheat, it is highly unlikely that these dicots will contain the same type of protein sequence found in wheat proteins that causes problems for celiac patients. Of course, some quirk of evolution could have given rise in these dicots to proteins with the toxic amino acid sequence found in wheat proteins. But if such concerns were carried to a logical conclusion, celiac patients would have to exclude all plant foods from their diets. For example, buckwheat and rhubarb belong to the same plant family (Polygonaceae). If buckwheat were suspect for celiac patients, should not rhubarb, its close relation, be suspect as well?

It may be in order to caution celiac patients that they may have undesirable reactions to any of these foods--reactions that are not related to celiac disease. Allergic reactions may occur to almost any protein, including proteins found in rice, but there is a great deal of individual variation in allergic reactions. Also, buckwheat, for example, has been claimed to contain a photosensitizing agent that will cause some people who have just eaten it to develop a skin rash when they are exposed to sunlight. Quinoa and amaranth may have high oxalate contents-approaching those of spinach and these oxalate levels may cause problems for some people. Such reactions should be looked for, but for most people, buckwheat, quinoa, or amaranth eaten in moderation apparently do not cause problems. (Buckwheat is sometimes found in mixture with wheat, which of course would cause a problem for celiac patients.) It seems no more necessary for all people with celiac disease to exclude buckwheat from their diets because some celiac patients react to it than it would be for all celiac patients to exclude milk from their diets because some celiac patients have a problem with milk.

In conclusion, scientific knowledge of celiac disease, including knowledge of the proteins that cause the problem, and the grains that contain these proteins, is in a continuing state of development. There is much that remains to be done. Nevertheless, steady progress has been made over the years. As far as I know, the following statements are a valid description of the state of our knowledge:

• Spelt or spelta and Kamut are wheats. They have proteins toxic to celiac patients and should be avoided just as bread wheat, durum wheat, rye, barley, and triticale should be avoided.
• Rice and corn (maize) are not toxic to celiac patients.
• Certain cereal grains, such as various millets, sorghum, teff, ragi, and Jobs tears are close enough in their genetic relationship to corn to make it likely that these grains are safe for celiac patients to eat. However, significant scientific studies have not been carried out for these latter grains.
• There is no reason for celiac patients to avoid plant foods that are very distantly related to wheat. These include buckwheat, quinoa, amaranth, and rapeseed oil (canola). Some celiac patients might suffer allergies or other adverse reactions to these grains or foodstuffs made from them, but there is currently no scientific basis for saying that these allergies or adverse reactions have anything to do with celiac disease. A celiac patient may have an allergy to milk, but that does not mean that all celiac patients will have an adverse reaction to milk. Again, however, scientific studies are absent or minimal for these dicots.

A list of my publications with pertinence to celiac disease follows. Cross-references to the literature for most of the points discussed above can be found in these publications.

• Kasarda, D. D., and DOvidio, R. 1999. Amino acid sequence of an alpha-gliadin gene from spelt wheat (Spelta) includes sequences active in celiac disease. Cereal Chem. 76:548-551.
• Kasarda, D. D. 1997. Celiac Disease. In Syllabus of the North American Society for Pediatric Gastroenterology & Nutrition, 4th Annual Postgraduate Course, Toronto, Ontario, Canada, pp. 13-21.
• Kasarda, D. D. 1997. Gluten and gliadin: precipitating factors in coeliac disease. In Coeliac Disease: Proceedings of the 7th International Symposium on Coeliac Disease (September 5-7, 1996), edited by M. Mäkki, P. Collin, and J. K. Visakorpi, Coeliac Disease Study Group, Institute of Medical Technology, University of Tampere,Tampere, Finland, pp. 195-212.
• Srinivasan, U., Leonard, N., Jones, E., Kasarda, D. D., Weir, D. G., OFarrelly, C., and Feighery, C. 1996. Absence of oats toxicity in coeliac disease. British Medical Journal 313:1300-1301.
• Tatham, A. S., Fido, R. J., Moore, C. M., Kasarda, D. D., Kuzmicky, D. D., Keen, J. N., and Shewry, P. R. Characterization of the major prolamins of tef (Eragrostis tef) and finger millet (Eleusine coracana). J. Cereal Sci. 24:65-71. 1996.
• Kasarda, D. D. 1994. Defining cereals toxicity in coeliac disease. In Gastrointestinal Immunology and Gluten-Sensitive Disease, edited by C. Feighery, and F. OFarrelly, Oak Tree Press, Dublin, pp. 203-220.
• Shewry, P. R., Tatham, A. S., and Kasarda, D. D. 1992. Cereal proteins and coeliac disease. In Coeliac Disease, edited by M. N. Marsh, Blackwell Scientific Publications, Oxford, U. K., pp. 305-348.
• De Ritis, G., Auricchio, S., Jones, H. W., Lew, E. J.-L., Bernardin, J. E. and Kasarda, D. D. 1988. In vitro (organ culture) studies of the toxicity of specific A-gliadin peptides in celiac disease. Gastroenterology 94:41-49.
• Kagnoff, M. F., Patterson, Y. J., Kumar, P. J., Kasarda, D. D., Carbone, F. R., Unsworth, D. J. and Austin, R. K. 1987. Evidence for the role of a human intestinal adenovirus in the pathogenesis of celiac disease. Gut 28:995-1001.
• Levenson, S. D., Austin, R. K., Dietler, M. D., Kasarda, D. D. and Kagnoff, M. F. 1985. Specificity of antigliadin antibody in celiac disease. Gastroenterology 89: 1-5.
• Kagnoff, M. F., Austin, R. K., Hubert, J. J., Bernardin, J. E. and Kasarda, D. D. 1984. Possible role for a human adenovirus in the pathogenesis of celiac disease. J. Exp. Med. 160: 1544-1557.

Grains in Relation to Celiac (Coeliac) Disease by Donald D. Kasarda.

The term gluten in reference to the cohesive, elastic protein mass remaining after starch is washed from a dough goes back to Beccari in 1745. Strictly speaking, gluten is found only in wheat because it is difficult to wash a cohesive protein mass even from rye, the closest relative to wheat, let alone from barley or oats or anything else. Unfortunately, a misuse of the term by the corn industry has become common in recent years. It has become fairly common to call corn storage proteins corn gluten. Personally, I think there is no justification for such usage. Corn may contain prolamins, as does wheat, but not gluten.

When it comes to celiac disease, a similar corruption of the term has become very common. There are certain related proteins in wheat, rye, and barley that give rise to particular peptides during digestion that are capable of triggering the responses typical of celiac disease. Only in the case of wheat can these be strictly considered to be derived from the gluten proteins. But for lack of a suitable term, patients and their physicians began speaking of gluten-free or gluten-containing foods. People ask me, How much gluten is there in quinoa? I have to translate this into, Are there any harmful peptide sequences in the proteins of quinoa? There is nothing in quinoa that is like gluten prepared from a wheat flour dough, which has an unusual, perhaps unique, viscoelastic character.

In any case, as far as we know, corn does not seem to cause harm to celiac patients. Corn has not been studied in the extensive way that wheat has in relation to celiac disease, but for 40+ years patients and their physicians have seemed to agree that corn is OK. The sequences in the corn zein (prolamin) fraction are suspicious, but they do differ in an apparently crucial way from the protein sequences of the wheat gliadin (prolamin) fraction. There have been no modern biopsy-based studies of the effects of purified corn proteins on the celiac intestine as there have been for wheat, but the mass of evidence still seems to point in the direction of corn being safe for celiac patients.

The connection with wheat (and rye and barley) wasnt recognized until the 1950s - (a)nd it wasnt until the 1960s that intestinal biopsies began to become commonly used in the diagnosis of celiac disease. With regard to the harmfulness of barley malt, the situation is complicated. I will give you my best shot with the qualification that the ideal experiments have not been done and a definitive statement is not possible at this time.

Because barley malt is made from barley grain that has been germinated it is reasonably certain to be less toxic than barley itself. The hordein proteins and starch in the endosperm of barley grains, like the equivalent gluten proteins and starch in wheat, are there for storage purposes. In a sense, they provide food for the new plant upon germination. In order to use the hordein proteins, the grain releases and generates enzymes upon germination that break down the storage proteins into their constituent amino acids. The problem is that the process is not complete during a short germination, so some peptides (short pieces of the proteins) remain intact in malted barley. There is experimental evidence for this. The resulting mix of peptides is highly complex.

We know from work described in the scientific literature that relatively small polypeptide chains can still retain activity in celiac disease and we know something about a few sequences that seem to be harmful. But we probably dont know all the sequences that are harmful and we havent put our fingers on the common theme that gives rise to the activity in celiac disease. So the question arises as to whether or not the remaining sequences in malted barley are harmful.

The possibilities that come to my mind are:

• There are sufficient remaining harmful peptides (with sizes including approximately 12 or more amino acid residues) to give a significant activity in celiac disease to barley malt (remember though that barley malt is usually a minor component of most foods in which it is used and processing might decrease the amount of harmful peptides in a malt product);
• There are traces of these peptides, but they are sufficiently minimal so as to cause no discernible harm; or
• The key harmful amino acid sequences are completely destroyed by the enzymes during germination (I can speculate that there might be an important enzyme, very active, in germination that clips a key bond in active sequences, thus reducing the concentration of those active sequences to almost nil while still allowing non-harmful peptides to exist; no evidence exists for this speculation, but it could be used as a working hypothesis for experimentation).

There is no completely solid evidence for or against there being a threshold of gluten consumption below which no harm, or at least no lasting harm, occurs and above which definite harm occurs (but see my previous post to the list on starch/malt question). This is a difficult area to study where zero consumption is being approached and the arguments that come up are at least similar to those that have arisen in regard to the question of whether or not there is a minimal level of radiation exposure below which no harm is caused, but above which there is harm that increases with dosage. Accordingly, celiac patients must choose arbitrarily the path they feel comfortable with.

Here are some references that deal with the question of peptide toxicity. It is not a simple situation:

• Shewry, P. R., Tatham, A. S., Kasarda, D. D. Cereal proteins and coeliac disease. In Coeliac Disease, Ed. M. N. Marsh. Blackwell Scientific, London 1992;pp. 305-348.
• Kasarda, D. D. Toxic cereal grains in coeliac disease. In: Gastrointestinal Immunology and Gluten Sensitive Disease: Proc. 6th International Symp. On Coeliac Disease, C. Feighery and C. OFarrelly, eds., Oak Tree Press, Dublin 1994;pp. 203-220.
• Wieser, H., Belitz, H.-D., Idar, D., Ashkenazi, A. Coeliac activity of the gliadin peptides CT-1 and CT-2. Zeitschrift fur Lebensmittel-Untersuchung und-Forschung 1986;182:115-117.
• De Ritis, G., Auricchio, S., Jones, H. W., Lew, E. J.-L., Bernardin, J. E., Kasarda, D. D. In vitro (organ culture) studies of the toxicity of specific A-gliadin peptides in celiac disease Gastroenterology 1988;94:41-49.
• Fluge, 0, K. Sletten, G. Fluge, Aksnes, L., S. Elsayed. In vitro toxicity of purified gluten peptides tested by organ culture. Journal of Pediatric Gastroenterology and Nutrition 1994;18:186-192.
• Sturgess, R., Day, P., Ellis, H. J., Lundin, K. A., Gjertsen, H. A, Kontakou, M., Ciclitira, P. J. Wheat peptide challenge in coeliac disease. Lancet 1994;343:758-761.
• Marsh, M. N., Morgan, S., Ensari, A., Wardle, T., Lobley, R., Mills, C., Auricchio, S. In vivo activity of peptides 31-43, 44-55, 56-68 of a-gliadin in gluten sensitive enteropathy (GSE). Supplement to Gastroenterology 1995;108:A871.

The following was written by Donald D. Kasarda who is a research chemist in the Crop Improvement and Utilization Research Unit of the United States Department of Agriculture. If you have any questions or comments regarding the piece, you can address them to Don at: Open Original Shared Link.

Most sprouted wheat still has gluten or gluten peptides remaining. Although the sprouting begins enzymatic action that starts to break down the gluten (a storage protein for the plant) into peptides and even amino acids. Generally this is not a complete process for sprouts used in foods so some active peptides (active in celiac disease) remain.

Abstract: The complete amino acid sequence of an alpha-type gliadin from spelt wheat (spelt) has been deduced from the cloned DNA sequence and compared with alpha-type gliadin sequences from bread wheat. The comparison showed only minor differences in amino acid sequences between the alpha-type gliadin from bread wheat and the alpha-type gliadin from spelt. The two sequences had an identity of 98.5%. Larger differences can be found between different alpha-type gliadin amino acid sequences from common bread wheat. Because all the different classes of gliadins, alpha, beta, gamma, and omega, appear to be active in celiac disease, it is reasonably certain that the spelta gliadin is also toxic. We conclude that spelta is not a safe grain for people with celiac disease, contrary to the implications in labeling a bread made from spelt as an alternative to wheat. Our conclusions are in accord with spelt and bread wheat being classed taxonomically as subspecies of the same genus and species, Triticum aestivum L. [References: 36]

Scand J Gastroenterol 1999 Feb;34(2):163-9
Kaukinen K, Collin P, Holm K, Rantala I, Vuolteenaho N, Reunala T, Maki M
Dept. of Medicine, Tampere University Hospital, Finland.

BACKGROUND: We investigated whether wheat starch-based gluten-free products are safe in the treatment of gluten intolerance. METHODS: The study involved 41 children and adults with coeliac disease and 11 adults with dermatitis herpetiformis adhering to a gluten-free diet for 8 years on average. Thirty-five newly diagnosed coeliac patients at diagnosis and 6 to 24 months after the start of a gluten-free diet and 27 non-coeliac patients with dyspepsia were investigated for comparison. Daily dietary gluten and wheat starch intake were calculated. Small bowel mucosal villous architecture, CD3+, alphabeta+, and gammadelta+ intraepithelial lymphocytes, mucosal HLA-DR expression, and serum endomysial, reticulin, and gliadin antibodies were investigated. RESULTS: Forty of 52 long-term-treated patients adhered to a strict wheat starch-based diet and 6 to a strict naturally gluten-free diet; 6 patients had dietary lapses. In the 46 patients on a strict diet the villous architecture, enterocyte height, and density of alphabeta+ intraepithelial lymphocytes were similar to those in non-coeliac subjects and better than in short-term-treated coeliac patients. The density of gammadelta(+)cells was higher, but they seemed to decrease over time with the gluten-free diet. Wheat starch-based gluten-free flour products did not cause aberrant up-regulation of mucosal HLA-DR. The mucosal integrity was not dependent on the daily intake of wheat starch in all patients on a strict diet, whereas two of the six patients with dietary lapses had villous atrophy and positive serology.

CONCLUSION: Wheat starch-based gluten-free flour products were not harmful in the treatment of coeliac disease and dermatitis herpetiformis.

Nahrung. 2003 Oct;47(5):345-8.

Celiac.com 01/14/04 – German researchers have developed a new test to determine the level of gliadin, the portion of gluten that is toxic to celiac patients, in foods. This new technique is called immunopolymerase chain reaction (iPCR), and it utilizes immunological detection of gliadin by a monoclonal antibody R5 conjugated when an oligonucleotide is amplified by PCR. The technique yields a "30-fold above the level reached by enzyme immunoassay" in laboratory tests, and it detects concentrations in food "as low as 0.16 ng/ml corresponding to 16 microgram gliadin/100 g food or 0.16 ppm (corresponding to 0.25 g of food extracted in 10 ml of solvent and 25-fold dilution of the extract prior to analysis)." This is the first time that this highly sensitive technique has been used for gliadin analysis, and "is the first approach to perform real-time iPCR in one step without changing the reaction vessels after enzyme immunoassay for subsequent PCR analysis thus minimizing risks of contamination and loss of sensitivity."