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.


  1. Way to put yourself out there Heather. I've been intentionally quiet about the ruling. I know how hard some people worked for years to get the FDA to do SOMETHING. And I am beyond appreciative of their efforts. But like you, I feel it falls short and it puts the needs of the inflicted a bit below the needs of the food companies.

    • Heather Jacobsen

      Yes, I know, GD. There are some people who have worked hard on this, and I appreciate all they've done to draw attention to the issue. I hope that I don't offend them. But I just haven't been able to rest easy on this issue for the past month, so I had to air my opinion. Thanks for your comment.

  2. Thanks for writing this. I know this was a victory for the advocates who worked for years to make this happen & it is good that the FDA legitimizes gluten free. But the ruling was weak. The 20ppm standard was disappointing (I agree on all your points) but it was expected. More disappointing to me were the details. A gluten free claim is voluntary and the FDA allows products derived from  gluten-containing grain  – so a product made from wheat or barley is ok if "processed" to eliminate gluten & tests low. NOT FOR MY FAMILY! They even acknowledge that testing for these processed grains is not accurate – but they allow it anyway. Of course, oats do not have to be certified gluten free. Scary!  As for compliance, manufacturers will be self regulated. Testing is technically not required, testing methods are up to the manufacturer, records do not need to be kept, the FDA "may" check up & violators will be "investigate". So, Christmas came early to manufacturers who have been interested in a piece of the gf pie but feared high standards. It is what it is but that doesn't mean we just deal with it, companies need to know that us guys with the wallets, our standards are higher.

    • Heather Jacobsen

      Thanks so much for elucidiating, this Jeanne. I missed the NFCA webinar, which I heard was happening just about the same time that I finished writing this post. But I'm hoping to get a copy of it.

      Each of these points you bring up are alarming to say the least. Its almost angering.


  3. Ann

    Hi – Just returned from the International Celiac Disease Conference in Chicago.  They did a presentation on this topic and Dr. Fasano and the woman from the FDA were there.  Without getting into too much of the science, I am convinced the 20ppm is without a doubt safe.  You would have to consume alot of gluten free replacement products to make any changes in your antibody tests and even more to make changes in your biopsy.  Dr. Fasano did another study of people who remain with symptoms.  Of 1200 patients, 2.3% had symptoms on a GFD.  He placed them on a whole foods diet (no GF replacement foods).  Their symptoms improved and then they were able to tolerate GF foods again.  Not sure how long they were on the whole foods diet.  I try to limit our replacement foods to the bare necessities to make life manageable with teenagers and mostly eat a paleo diet with rice and potatoes and so far so good.Another presenter presented a study about wheat starch – randomized trials with no ill effects to CD patients.  Too bad though on the ruling for oats – I guess you need to check with manufacturers and only buy trusted sources and not buy other GF products with oats as an ingredient.  They are also working on guidelines for fermented and hydrolyzed foods such as yoghurt – that will be coming so in the meantime none of those foods are regulated.

    • Heather Jacobsen

      Thank you for sharing your opinion. Yes, I cited that study that you mention (#11) . They were eating whole foods for 3 to 6 months.

      What is confusing to me is that he says 2.3% of patients "had symptoms", whereas studies #1 and #2 that I cited, say pretty much the opposite. So why does he believe the standard GFD is fine for most people, and yet two other independent researchers say that the standard GFD is not helping 74 – 92% of CD Patients?!

      Just curious, how did the wheat starch presenter define "ill effects to CD patients?"


      • Ann

        I am typing up my notes now and will send you info when I get organized – it was a bit overwhelming, each speaker only had about 10 minutes so, lots of info in a short amount of time.  I did get a booklet of summaries of studies – I can find that reference for you in the next day or two.  Lots of talk about FODMAPs as a potential reason for continuing symptoms.  Age at diagnosis is also a factor as well as dysbiosis, SIBO being the main culprit.  The field is really exploding – lots of people looking at the great mysterious microbiome so I think we will have more answers in the coming years.  They were all quick to admit that there are still so many unanswered questions especially in the areas of non-celiac gluten sensitivity and why so many adults in particular still have symptoms after a GFD.  I was just treated for SIBO – will be curious to see if I can tolerate FODMAPs again and and the occasional restaurant meal.  I know I have been trying to figure things out on my own because I have had no luck with GI docs, but now I am thinking I need to go to a celiac center and try to have them figure out what is wrong and also to raise awareness among the docs that GFD isn't the end of the story.    Its a journey! 

        • Heather Jacobsen

          It is most definitely a journey! Yes, there is still so much to learn. I look forward to us unraveling the mystery.  I did see that FODMAP/GS study, although I haven't had a chance to dig deeply into it yet.

  4. Pat Minnigh

    I appreciate all all of the comments on this. Interestingly enough, I did help advocate for it with Jules Shepard when she made the 2 story GF cake in DC to spur the politicians to make a decision. This may not be the best threshold of acceptable gluten for several of us, but studies have shown that it is acceptable for the majority of celiacs. Not having a standard, as we have had for a long time, has allowed anyone and everyone to claim their product is gluten free even though it isn’t! One fellow in our group purchased a bag of GF pretzels that were not GF at all and he was very sick! If you are sensitive, as I am, you look for the certified seals on you favorite GF products from CSA or GIG. They test at 5 to 10 ppm. Our purchasing habits will dictate how the manufacturers decide the gluten content. I have a question, have any of you reacted to Bob’s Red Mill products?

    • Heather Jacobsen

      Thank you for your comment, Pat. I can't say for sure if I've reacted to Bob's Red Mill. I can say that I'm mostly on a paleo diet now, because eating meals made with GF flour and GF grains, did not help me to feel better. 12 years ago, when I  went GF, there were not a lot of GF products on the market, so I did not eat a lot of baked goods, and especially no processed foods. And I felt fine back then! But in the past couple of years, as I started experimenting with GF baking, snacking on GF crackers, etc. I started feeling ill again.  I'm assuming this is because of gluten cross-contamination but I don't know for sure. I do know that I am very sensitive to gluten, though.

  5. It’s important to note that wheat, rye, barley & oats (not gluten free) can be in a product and if a test doesn’t show gluten at 20ppm or more then the product can be labelled as gluten free. Additionally, the molecules of gluten can be broken and if the product tests below 20ppm then it can be labelled gluten free. Just because the test shows gluten free at 20 ppm, doesn’t mean the right measurement tool is being used and it doesn’t mean that it is safe for celiacs or the allergic. I recommend keeping in touch with Tricia Thompson’s work at

    • You are absolutely right, Melanie. And thanks for your comment. It reminded me to update this post with more research that I have uncovered. Namely, several more articles in the medical research showing that even trace amounts of gluten are unsafe, including a comprehensive study done by the FDA itself, which for some reason was not considered when they decided on these labeling laws! Please see above for those references.


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