Are Oats Safe to Eat on a Gluten Free Diet?
Oats are commonly recommended for those going on a gluten free diet as a safe substitute food. The classic or traditional definition of gluten includes only wheat, barley, rye (sometimes oats, sometimes not). So the big question is – Are Oats Safe to Eat on a Gluten Free Diet?
Why All the Confusion?
The common response I hear back from people is – “Dr. Osborne, I don’t feel bad when I eat oatmeal.” or “My other doctor says that oatmeal is safe.” or “The package of oatmeal claims to be gluten free.”
Keep in mind the following: It is not how bad you feel after consumption that tells you whether or not you are having an inflammatory immune reaction. This type of damage can take years to manifest into symptoms. That is one of the primary reasons that most people diagnosed with gluten problems don’t get their diagnosis until later in life. The inflammatory damage builds over time, and is typically not an immediate response. The food labeling laws don’t include oatmeal because there is not a firm scientific consensus. Many claim that celiac patients react to oats only because they are cross contaminated with wheat. And although it is true that many packaged grain products are cross contaminated, non cross contaminated oats have also been shown to cause an inflammatory reaction in patients diagnosed with gluten intolerance. The bigger problem here is that doctors and the gluten free food industry completely ignore the research on this topic, and continue to claim that oats are a safe substitute food. But before you make a decision to include oat cereal products into your diet, consider the research studies below:
Current Research on Oats
There have been a number of research studies performed to evaluate the safety of oat consumption. Many of them report that components in oat proteins cause inflammation and elicit damage in patients with gluten sensitivity. Most recently, a study published in the European Journal of Nutrition found that some forms of oat protein triggered and antibody reaction. Another study published in the Scandinavian Journal of Gastroenterology found two varieties of oat proteins were responsible for increased intraepithelial T-cell density and IFN-γ production (both of these are signs of increased inflammation).
In 2012 a research study was published identifying a…
direct correlation of the immunogenicity of the different oat varieties with the toxicity of peptides present in their avenin sequences.
In plain English please – Proteins in oat cereal stimulated an immune response similar to what is seen from wheat.
The studies above were all published after Jan. of 2011. In medicine, it can take 20-30 years for new information to become common knowledge among doctors. So I don’t expect that many physicians will be talking about the potential for oat to be a problem for those with gluten sensitivity. That being said, let’s take a look at a comprehensive review of the medical literature that was published in 2011 compiling 75 studies published on the topic since 1953. The summary from the authors are quoted below:
Oats in a gluten-free diet increase the diet’s nutritional value, but their use remains controversial. Contamination with prolamins of other cereals is frequent, and some clinical and experimental studies support the view that a subgroup of celiac patients may be intolerant to pure oats. Thus, this issue is more complex than previously suggested. In order to produce oats that are safe for all celiac patients, the following topics should be addressed: selection of oat cultivars with low avenin content, research on such recombinant varieties of oats, development of assay methods to detect avenins in oat products, guidelines for the agricultural processing of oats and the manufacture of oat products, as well as guidelines for following up with celiac patients who consume oats.
- Silano M, et al. Diversity of oat varieties in eliciting the early inflammatory events in celiac disease. Eur J Nutr
- Maglio M, Mazzarella G, Barone MV, et al. Immunogenicity of two oat varieties, in relation to their safety for celiac patients.Scand J Gastroenterol. 2011 Oct;46(10):1194-205.
- Real A, Comino I, de Lorenzo L, et al. Molecular and immunological characterization of gluten proteins isolated from oat cultivars that differ in toxicity for celiac disease. PLoS One. 2012;7(12).
- Fric P, Gabrovska D, Nevoral J. Celiac disease, gluten-free diet, and oats. Nutr Rev. 2011 Feb;69(2):107-15.
Oat Safety Summary
Oats contain a form of gluten often times referred to as avenin, and this protein represents 12-16% of the total protein found in oats. This in and of itself makes it virtually impossible for oats to be gluten free. This number is low compared to the 69% gluten protein composition of wheat, and it may in part account for the fact that people report less negative reactions when consuming oats. It is well established the 20 ppm (parts per million) – roughly the size of a bread crumb is enough gluten to create and inflammatory reaction in patients with gluten sensitivity. It has also been shown that many patient embarking on a traditional gluten free diet (avoiding wheat, barley, and rye, but not other grains) continue to remain ill. The diagram below compares the gluten protein content of different grains:
The bulk of scientific literature investigating oat safety is in agreement that more research is needed before making a blanket statement that oats are safe for everyone. Some laboratories now offer limited testing for oat allergy. These labs are not accurate enough and do not investigate the inflammatory response to oats in a comprehensive manor, and therefor should not be the basis to include oats in the diet. Because it is currently not possible to extract the forms of oat gluten known to cause damage out of the cereal, avoidance of oats as a substitute food for a gluten free diet is strongly recommended.
- There is no such thing as a “gluten free” oat.
- As many as 41% of processed packaged foods labeled gluten free contain enough gluten to cause damage (oats included)
- 20 ppm exposure can allow for persistent damage
- Several types of gluten protein in oats have been shown to cause inflammation
- Although often times labeled gluten free, oats contain gluten.