Is FDA’s gluten-free labeling requirement of less than 20 ppm gluten really safe?

updated March 29, 2015


Dear Gluten-Free Community,

I’m confused. And I need your help!

One summer morning, last month, I turned over in bed, opened my sleepy eyes and turned on the radio to hear the 7 am news.  I was amazed to hear the FDA ruling on gluten-free labeling had been finalized – and had made NPR headline news! BUT I didn’t jump up and down with glee. I laid in bed a while longer, as I struggled to come to terms with my emotions. Is this really great news?

Over the course of the day, I watched gluten-free people everywhere virtually high-fiveing, as they rejoiced in celebration over Twitter and other social media. Meanwhile, I was feeling down, a little confused, and very alone in my thoughts.

Here’s why:

Numerous studies show that complete recovery from celiac disease is rare, even when people are adhering to the gluten free diet [1 – 6]. In fact, one studies shows that 92% of celiacs do not achieve “complete mucosal recovery.”  That’s huge! Let me reiterate: The vast majority of people who go on a gluten-free diet for medical reasons, never completely heal! Why are we not talking more about this? And why does everyone keep pushing the gluten-free diet as we know it, if it’s got such a low performance record?

The traditional gluten-free diet (GFD as its called in medical literature) is defined as a diet that is void of wheat, barley and rye. Oats are not even considered part of the GFD anymore (which I don’t agree with).

So why aren’t most people healing on the GFD? One likely possibility is because 32% of inherently gluten-free grains are cross-contaminated with more than 20ppm of gluten [7]. This means that if your buckwheat or millet or quinoa is not labeled gluten-free, don’t assume it is.

New legislation now requires foods that are labeled gluten-free to have less than 20ppm (parts per million) of gluten in then.  So foods labeled ‘gluten-free’ are not really gluten-free.  They are low-gluten. Even if one serving of this food may not cause a reaction, those small amounts of gluten can add up over the course of the day if you are eating such gluten-free foods at every meal. By the end of the day, you may have consumed as much as 10mg to 13 mg of gluten [8] [9]. I don’t know about you, but I don’t even want to consume ONE mg of gluten.

But now that we have standards in place will you at least be able to trust those packaged food products that are labeled as gluten-free? As of mid-2013, most manufacturers of gluten-free foods were already voluntarily producing foods with this standard in place, so we probably won’t see any drastic changes to our GF food system [10]. The new legislation will just ensure that manufacturers new to the gluten-free industry will also comply with the 20ppm standard. By the way, testing for trace amounts of gluten in one’s products before they hit the grocery store shelves is voluntary on the part of the food manufacturer. So we have to just have faith that these companies are adhering to the law.

Even if they are, is that enough? Is 20 ppm of gluten really safe? If so, why did Australia and New Zealand rule that it should be 3ppm?

One study by Catassi and colleagues, published in 2007, is continually referenced to support the idea that 20ppm or less is deemed to be safe [11]. However, upon reading the entire study, I don’t see where it actually says that 20ppm is safe. They say that 50 mg of gluten per day is a “minimum dose required to produce measurable damage” and that “the threshold of 20 ppm keeps the intake of gluten… well below the amount of 50 mg/d…”

They conclude that the

intake of 50 mg gluten/day produced significant damage in the architecture of the small intestine in patients being treated for CD. However, the sensitivity to trace intakes of gluten showed large interpatient variability, a feature that should be accounted for in the implementation of a safe gluten threshold… Finally, the relation between the intestinal damage induced by trace intakes of gluten and the long-term complications of CD remains to be elucidated.

What this says to me: We know 50 mg/d of gluten causes intestinal damage. We don’t know at what point trace amounts of gluten cause damage. And it’s different from one person to the next. So let’s arbitrarily pick 20ppm because if you eat several gluten-free foods that contain 20ppm of gluten in one day, at least you won’t reach the 50 mg per day that we know causes damage. And by the way, we also don’t know what long-term exposure to trace amounts of gluten will do to celiac patients.

I believe that this study is inherently flawed.

First, It assumes that unless there is measurable intestinal damage, then gluten is not harming us. But we know that villous atrophy actually happens in a patchy distribution [12], so a biopsy that shows no histological changes, does not necessarily always indicate a disease-free patient.

Second, there are many other ways that gluten can affect a person besides the gut. For instance, dermatitis herpetiformis (DH) is a gluten-induced skin disorder associated with celiac disease, but 20% of DH patients show “apparently normal small bowel mucosal architecture As another example, gluten ataxia is a very serious disorder that affects the brain and yet, patients have developed “severe neurological symptoms” without “gluten-dependent small bowel mucosal atrophy.” This supports the notion that “coeliac disease clearly exists beyond villous atrophy, [and]… small intestinal villous atrophy is only one manifestation of genetic gluten intolerance [14].

And what about the other approximately 200 (and counting) other medical conditions associated with gluten? While celiac disease is an autoimmune disorder that affects less than 1% of the population, (and mucosal damage is most often how it is diagnosed), gluten sensitivity (GS) affects 8 to 12% percent of the world’s population (and possibly even much more [15]). GS patients exhibit symptoms similar to celiac disease, but biopsies and blood tests come back negative for celiac disease. In fact, 50 to 75% of GS patients never even complain about digestive distress [16]! So how do we know that trace amounts of gluten aren’t still hurting us, especially if we know, as already stated, that the vast majority of patients on the standard GFD do not heal!?

Just because 19ppm of gluten ingested (several times over the course of a day) doesn’t show histological damage (the majority of time in one study) does not prove that it’s safe! In fact, one subject, who was only consuming 10 mg/day of gluten (not the 50 mg that other volunteers were asked to consume), did not complete the study because he experienced “full clinical relapse.” Obviously, this person would be taking risks by eating any product on the grocery store shelf that is labeled “gluten-free.”

There are other studies that have looked at minimum dose tolerability of gluten, and most of those results show something much different, some as low as 1.5mg/day to 4.8 mg/day [17] [18]. There even two case studies of patients strictly adhering to their gluten-free diets, except for one communion wafer a week. That one communion wafer caused each of them “mucosal harm.” That is, there are indeed patients for whom even just ONE milligram of gluten a day causes harm [19] [20]!

In 2011, the US Food and Drug Administration (FDA)’s Center of Food Safety and Applied Nutrition conducted a comprehensive review of all the literature that examined gluten exposure to “sensitive” individuals, including the Catassi study, as well as those that fall at the much lower end of the spectrum of tolerable dosage findings. The FDA committee points out that

 the most sensitive subjects may not have been tested in the food challenge in [the Catassi] study because subjects with persistent morphological abnormalities after a strict GFD pre-challenge period were not included as study subjects.

That is, if patients weren’t healing on the GFD, they weren’t included in the study! This may explain why their allowance of just below 50 mg/day is so much higher than those seen in other studies.

The FDA performed an analysis of all these studies, and they concluded that symptoms from ingesting gluten begin with as little as .015 mg/day with actual intestinal damage being found at 0.4 mg/ day! They equate this to less than 1 ppm level of gluten in foods as being the safest amount for those most sensitive to gluten [21]. That’s a big difference!

Why is the FDA’s own analysis not the one study being cited to guide it’s labeling laws? Does anyone else think this is strange?

In 2013, Dr. Fasano and his colleagues published an article that looked at a group of people who did not heal on the GFD and asked them to go on what they called a Gluten Contamination Elimination Diet (GCED), which was a mostly grain-free diet, in an effort to remove any chances of being cross-contaminated by trace amounts of gluten. Only white and brown rice were allowed. And what was the response rate?  82% of patients on a diet that removed trace amounts of gluten responded well to the treatment [22]. Personally, I wonder if more people might have healed, too, if rice were removed, since we know that rice can cross-react with glutenin antibodies [23].

Clearly, the gluten-free diet as it stands now is not enough, and removing trace amounts of gluten has met with great response. There is also plenty of anecdotal evidence to support this. Just look at the sheer number of people adopting the “paleo” diet (a grain-free diet) because they did not respond well to the standard GFD.

So why was there so much celebration on the passing of this regulation, if most people on the standard gluten-free diet never heal, and what they’ve already been eating won’t be affected much by the law, anyway? I am mostly worried about the newly diagnosed celiac or gluten-sensitive patient, who will be roaming grocery store shelves for help, and will be inundated with GF products that they believe are going to help them finally get better, after months, maybe years of agony.  But will they get any better?

The only people who are benefiting from the 20ppm threshold are gluten-free food manufacturers, who (combined) are making billions of dollars a year [24] off consumers who think that gluten-free products are healthier for them. You don’t even have to read between the lines, when Dr. Fasano, a co-author of the Catassi study, says in his letter, In Defense of 20ppm [25] that setting a safe gluten-free threshold below 20 ppm would be harmful to manufacturers because the limits are too restrictive and that US manufacturers would not be able to “compete successfully in the gluten-free global marketplace.” So is that what it’s really about?  Fasano goes on to say, “under these restrictive limits, manufacturers would either discontinue gluten-free products or be forced to create much more expensive and much less palatable products, resulting in a drastic loss of selection and quality.”

That would be a shame, then, because gluten-free sensitive people everywhere would be forced to get the majority of their calories from fresh, whole foods.




[1] Intestinal Damage from Celiac Disease Persists in Adults, Even with Gluten-free Diet. National Institute of Diabetes and Digestive and Kidney Diseases. September 2011.

[2] Bardella MT, Velio P, Cesana BM, Prampolini L, Casella G, Di Bella C, Lansini A, Gambarotti M, Bassotti G, Villanacci V. Coeliac diease: a histological follow-up study. Histopathology. 2007. Mar; 50(4): 465-71.

[3] Lanzini A, Lanzarotto F, Villanacci V, Mora A, Bertolazzi S, Turini D, Carella G, Malagoli A, Ferrante G, Cesana BM, Ricci C. Complete recovery of intestinal mucosa occurs very rarely in adult coeliac patients despite adherence to gluten-free diet. Aliment Pharmacol Ther. 2009 Jun 15;29(12):1299-308.

[4] Lee SK, Lo W, Memeo L, Rotterdam H, Green PH. Duodenal histology in patients with celiac disease after treatment with a gluten-free diet. Gastrointest Endosc. 2003 Feb;57(2):187-91.

[5] Ciacci C, Cirillo M, Cavallaro R, Mazzacca G. Long-term follow-up of celiac adults on gluten-free diet: prevalence and correlates of intestinal damage. Digestion. 2002;66(3):178-85.

[6] Rubio-Tapia A, Rahim MW, See JA, Lahr BD, Wu TT, Murray JA. Mucosal recovery and mortality in adults with celiac disease after treatment with a gluten-free diet. Am J Gastroenterol. 2010 Jun;105(6):1412-20.

[7] Thompson T, Lee AR, Grace T. Gluten contamination of grains, seeds, and flours in the United States: a pilot study. Journal of the American Dietetics Associaton. 2010 Jun; 110(6):937-40.

[8] Anderson, Jane. What does it mean for products to have less than 20 parts per million of gluten? Last updated December 2014.

[9] Mooney et al. 2012. Treatment Failure in Coelic Disease: A practical Guide to Investigation and Treatment of Non-responsive and Refractory Coelic Diease. J Gastrointestin Liver Dis June 2012. Vol. 21 No 2, 197-203.

[10] Anderson, J. 2014.

[11] Catassi C, Fabiani E, Iacono G, D’Agate C, Francavilla R, Biagi F, Volta U, Accomando S, Picarelli A, De Vitis I, Pianelli G, Gesuita R, Carle F, Mandolesi A, Bearzi I, and Fasano A. A prospective, double-blind, placebo-controlled trial to establish a safe gluten threshold for patients with celiac disease.  Catassi,  Carlos, et al.  Am J Clin Nutr 2007. 85:160 – 6.

[12] Arzu Ensari, MD, PhD, Gluten-Sensitive Enteropathy (Celiac Disease). Controversies in Diagnosis and Classification. Arch Pathol Lab Med. 2010;134:826–836.

[13]  Katri Kaukinen, Pekka Collin, Markku Mäki. Latent coeliac disease or coeliac disease beyond villous atrophy? Gut. 2007 October; 56(10): 1339–340.

[14] Ibid.

[15] Anderson J. Mon-Celiac Gluten Sensitivity Research. New Research Explains How Gluten Sensitivity Differs From Celiac Disease. CeliacDisease.About.Com

[16] Petersen V and Petersen R. The Gluten Effect. How “Innocent Wheat is Ruining Your Health. True Health Publishing. 2009. 403 pp.

[17] Chartrand, L. Russo PA, Duhaime AG, Seidmain EG. Wheat starch intolerance in patients with celiac disease. J Am Diet Assoc 97(6): 612-618. 1997.

[18] Ciclitira PJ, Ellis HJ, Fagg, NLK. Evaluation of gluten free product containing wheat gliadin in patients with celiac disease. Br Med J 289: 83, 1984.

[19] Biagi F, Campanella J, Martucci S, Pezzimenti D, Ciclitira PJ, Ellis HJ, Corazza GR: A milligram of gluten a day keeps the mucosal recovery away: a case report. Nutr Rev 2004;62:360-363.

[20] Auricchio S, Troncone R. Effects of small amounts of gluten in the diet of celiac patients. Panminerva Med 33: 83-85, 1991.

[21] Food & Drug Administration, Office of Food Safety, Center of Food Safety and Applied Nutrition. Health Hazard Assessment for Gluten Exposure in Individuals with Celiac Disease: Determination of Tolerable Daily Intake Levels and Levels of Concern for Gluten. May 2011. p. 32.

[22] J Braly and R Hoggan. Dangerous Grains. Why Gluten Cereal Grains May Be Hazardous to Your Health. 2002. Avery. New York. 244 pp.

[23] Hollon J, Cureton P, Martin M, Puppa E and Fasano, A. Trace gluten contamination may play a role in mucosal and clinical recovery in a subgroup of diet-adherent non-responsive celiac disease patients. BMC Gastroenterology 2013, 13:40.

[24] Gluten Free is Still Going Gang Busters.

[25] “In Defense of 20 Parts Per Million” A Letter from Alessio Fasano, M.D., and The University of Maryland Center for Celiac Research. August 2011.

Heather Jacobsen

Using my MSc to unravel the health & science behind grains, gluten & the gluten-free/paleo lifestyle. Foodie, photographer, mommy.