GLUTEN WHAT IS THAT?
In the field of gluten intolerance such as gluten sensitivity or celiac disease, gluten is a collective term for storage proteins of wheat, rye, barley, oats and other cereals. Specifically, these proteins are called gliadins and glutenins (wheat), secalins (rye), hordins (barley), and avenins (oats).
People with gluten sensitivity can often tolerate small amounts of gluten without developing symptoms. For this group of people, it is therefore a matter of finding out the personal tolerance limit so that no symptoms occur. This is often a long way and requires a lot of patience and a distinct knowledge of how much gluten is present in which foods.
In contrast, even the smallest trace of gluten has consequences for people with celiac disease. Scientists agree that even a few milligrams of gluten damages the intestinal mucosa. In very sensitive individuals, even one milligram a day is enough to cause chronic inflammation and damage. A strict gluten-free diet helps control symptoms so the damaged intestine can heal. Eating any small amount of gluten again will cause further damage. Therefore, celiac patients should do everything possible to avoid gluten intake. However, gluten is often ingested unknowingly, for example through contamination or residual gluten in gluten-free labeled products (20 ppm rule). Studies show that even on a supposedly gluten-free diet, unintentional gluten intake can range from 150 mg to 400 mg per day.
10 milligrams of gluten per day is generally considered by many experts to be a safe amount for the majority of people with celiac disease. There are still differing opinions as to how much gluten can be considered safe for people with gluten intolerance, as each sufferer has different sensitivities after all. For this reason, there are countries such as Australia that do not specify 20 ppm as the limit for gluten-free products, as is the case in Germany, but 0 ppm or the detection limit (currently 3 ppm). If gluten can be detected, it must not be labeled gluten-free.
In 2011, the U.S. Food and Drug Administration (FDA) published an assessment of the health hazards of gluten in people with celiac disease. Based on a comprehensive review of the literature available at the time, this report concluded that the safe tolerable amount of gluten is 7 mg daily to prevent histological changes and 0.015 mg per day to prevent symptoms.
GLUTENFREE PRODUCTS
There are more and more products declared as "gluten-free" to buy. "Gluten-free" means that a maximum content of 20 mg gluten prp kg food is observed. Similarly, a "very low gluten content" according to EU regulation means that products do not exceed the limit of 100 mg gluten per kg of food. Unfortunately, for both gluten contents, the product may be labeled "Specially formulated for people with gluten intolerance" or "Specially formulated for people with celiac disease" according to Commission Implementing Regulation (EU) No. 828/2014 of July 30, 2014. In our view, this is not correct because it is still unclear what amounts of gluten per day are considered safe for sensitive individuals. We would prefer the detection limit as a threshold.
METHOD
A liquid chromatographic method was used to quantify gluten in cereal flours and in cereal products, and the antibody-based detection method "Enzyme Linked Immunosorbent Assay" (ELISA) was used for beers.
| Gluten levels in cereals and flours | Indication in milligrams gluten per 100 g food | Indication in grams of food per 10 mg gluten |
| FOOD | AVERAGE | AVERAGE |
| Wheat (whole grain) | 7700 | 0,130 |
| Spelt (whole grain) | 9894 | 0,101 |
| Rye (whole grain) | 3117 | 0,321 |
| Oat (whole grain) | 4557 | 0,219 |
| Barley (whole grain) | 5624 | 0,178 |
| Green spelt (whole grain) | 7100 | 0,141 |
| Wheat flour Type 405 | 8660 | 0,115 |
| Wheat flour Type 550 | 7520 | 0,133 |
| Wheat flour Type 630 | 9359 | 0,107 |
| Wheat flour Type 812 | 9420 | 0,106 |
| Wheat flour Type 1050 | 8740 | 0,114 |
| Wheat flour whole grain | 8300 | 0,120 |
| Wheat bran | 4660 | 0,215 |
| Wheat grits | 8680 | 0,115 |
| Spelt flour Type 630 | 10300 | 0,097 |
| Spelt flour whole grain | 9460 | 0,106 |
| Green spelt flour whole grain | 8975 | 0,111 |
| Rye flour Type 815 | 3200 | 0,313 |
| Rye flour Type 997 | 3180 | 0,314 |
| Rye flour Type 1150 | 3483 | 0,287 |
| Rye flour Type 1370 | 3300 | 0,303 |
| Rye bread whole grain | 3450 | 0,290 |
| Oat flour whole grain | 5600 | 0,179 |
| As expected, wheat and the manufactured flours contain the highest gluten levels. Only spelt and spelt flours have higher values. | ||
| Gluten levels in cereals and flours | Indication in milligrams gluten per 100 g food | Indication in grams of food per 10 mg gluten |
| FOOD | AVERAGE | AVERAGE |
| Porridge | 4850 | 0,206 |
| Oat flakes | 5660 | 0,177 |
| Barley grains | 4700 | 0,213 |
| Buns | 9183 | 0,109 |
| Wheat toast | 6900 | 0,145 |
| Wheat flour bread | 5780 | 0,173 |
| Whole grain wheat bread | 6500 | 0,154 |
| Mixed wheat bread | 3840 | 0,260 |
| Crispbread | 3600 | 0,278 |
| Mixed rye bread | 3300 | 0,303 |
| Rye bread | 1200 | 0,833 |
| Whole grain rye bread | 1580 | 0,633 |
| Egg pasta uncooked | 9040 | 0,111 |
| Egg pasta cooked | 4300 | 0,233 |
| Butter Biscuit | 5240 | 0,191 |
| Cake base | 2160 | 0,463 |
| The greater the proportion of wheat in the product, the higher the gluten level. | ||
| Gluten Levels in different types of Beers | Indication in milligrams gluten per 100 g food | Indication in grams of food per 10 mg gluten |
| FOOD | AVERAGE | AVERAGE |
| Full beer light | 2,7 | 370,370 |
| Full beer dark | 4,6 | 217,391 |
| Wheat beer | 274 | 3,650 |
| Pilsener | 1,2 | 833,333 |
| non-alcoholic beer | 3,2 | 312,500 |
| Malt beverage | 3,3 | 303,030 |
| White beer is a no-no for celiac patients. At 1.2 mg per 100 g, a Pilsner lager could possibly be acceptable for gluten-sensitive people, but for safety reasons only beer labeled gluten-free should be consumed. | ||
SOURCE:
G. Andersen / H. Köhler in collaboration with M. Rubach / W. Schaecke (2015): Annual Report of the German Research Institute 2014, Freising, p. 136 - p. 139. Slot, I. & Bremer, M.G.E.G. & Hamer, R.J. & Van der Fels-Klerx, HJ (Ine). (2015). Part of the celiac population remains at risk despite current gluten limits. Trends in Food Science & Technology. 43. 10.1016/j.tifs.2015.02.011.Cohen, Inna & Day, Andrew & Shaoul, Ron. (2020). Should the Glu Be Ten or Twenty? An Update on the Ongoing Debate on Gluten Safety Limits for Patients with Celiac Disease. Gastrointestinal Disorders. 2. 202-211. 10.3390/gidisord2030021. Reid, J., Allen, K., & McDonald, S. (2016). Systematic review of safe gluten levels for people with celiac disease. Cochrane Australia. http://www.coeliac.org.au/research/ Food and Drug Administration. Health Hazard Assessment for Gluten Exposure in Individuals with Celiac Disease: Determination of Tolerable Daily Intake Levels and Levels of Concern for Gluten. 2011.