Oats: Beyond Cross Contamination
Until fairly recently, the gluten-free diet consisted of "no wheat, rye, barley or oats". Now specially-grown "gluten-free" oats are routinely recommended even though they are not safe for everyone with CD! With no easy way to determine who will react to oats, this is an area where extreme caution should be used to prevent continued illness.
There is a thorough discussion of oats, including many cautions, in this 2016 document by the Celiac Center at Beth Israel Deaconess Medical Center: See pages 11-14 of Following a Gluten Free Diet
Interestingly, some cultivars of oats have been shown to be safer than others and research in this area may eventually result in the availability of completely safe oats. (This variation in the level of oat toxicity may account for some of the inconsistency in study results over the years, where oat variety was not taken into consideration).
2015: Ingestion of oats and barley in patients with celiac disease mobilizes cross-reactive T cells activated by avenin peptides and immuno-dominant hordein peptides and another article about this research conclude 8% of CD patients studied had an immune reaction to oats. A quote from one of the authors: "Our study highlights that eating oats can have immune-activating effects similar to barley".
2015: Gliadin and avenin toxicity studies of duodenal biopsy tissue in organ culture experiments (see page 100 of the Proceedings of the 29th meeting of the Working Group on Prolamin Analysis and Toxicity)
"In this study, we attempted to develop an in vitro assay which would examine the question of whether a prolamin fraction from oats caused damage to coeliac biopsy tissue in culture. Since enterocyte damage is an early feature of gliadin mediated damage, we employed E-caderin and cytokeratin 20 staining of enterocytes with confocal microscopy to investigate this question. In the case of tissue from normal controls, there appeared to be no evidence of damage caused by the prolamin fractions. Gliadin caused changes in E-cadherin staining in four of the five coeliac subjects. However, avenin appeared to cause similar changes in three of the five coeliac biopsy experiments. Unfortunately, cytokeratin 20 staining was too unreliable to add meaningful information to the studies.
2014: The Spectrum of Major Seed Storage Genes and Proteins in Oats (Avena sativa)
From the conclusions: Although oats are purported to be safe for celiac patients, lacking has been a complete description of the oat seed proteins in at least one specific germplasm, and then available for epitope analysis and to serve as a baseline for comparing different oat cultivars.
2014: Noncontaminated dietary oats may hamper normalization of the intestinal immune status in childhood celiac disease
This study found that a substantial fraction of pediatric CD patients seem to not tolerate oats (it looks like about 30% - ed.). This table summarizes the results.
2013: Diversity of oat varieties in eliciting the early inflammatory events in celiac disease
2011: Diversity in oat potential immunogenicity: basis for the selection of oat varieties with no toxicity in coeliac disease
2011: Immunogenicity of two oat varieties, in relation to their safety for celiac patients.
2009: Introduction of oats in the diet of individuals with celiac disease: a systematic review.
2007: Avenins from different cultivars of oats elicit response by coeliac peripheral lymphocytes.
2007: In vitro tests indicate that certain varieties of oats may be harmful to patients with coeliac disease
2004: The Molecular Basis for Oat Intolerance in Patients with Celiac Disease
This study demonstrated that some people with celiac disease do react to pure oats. The people who participated in this study were selected specifically because they believed they had reacted to oats in the past. Some of them were shown to be truly having damage from oats, while others in the study were not. (You can also read a news article about this study).
Six potentially reactive portions of the oat gluten protein were found in "Identification and Analysis of Multivalent, Proteolytically Resistant Peptides from Gluten". T cells reacted to oat gluten in a study by Kilmartin.
There is a thorough discussion of oats, including many cautions, in this 2016 document by the Celiac Center at Beth Israel Deaconess Medical Center: See pages 11-14 of Following a Gluten Free Diet
Interestingly, some cultivars of oats have been shown to be safer than others and research in this area may eventually result in the availability of completely safe oats. (This variation in the level of oat toxicity may account for some of the inconsistency in study results over the years, where oat variety was not taken into consideration).
2015: Ingestion of oats and barley in patients with celiac disease mobilizes cross-reactive T cells activated by avenin peptides and immuno-dominant hordein peptides and another article about this research conclude 8% of CD patients studied had an immune reaction to oats. A quote from one of the authors: "Our study highlights that eating oats can have immune-activating effects similar to barley".
2015: Gliadin and avenin toxicity studies of duodenal biopsy tissue in organ culture experiments (see page 100 of the Proceedings of the 29th meeting of the Working Group on Prolamin Analysis and Toxicity)
"In this study, we attempted to develop an in vitro assay which would examine the question of whether a prolamin fraction from oats caused damage to coeliac biopsy tissue in culture. Since enterocyte damage is an early feature of gliadin mediated damage, we employed E-caderin and cytokeratin 20 staining of enterocytes with confocal microscopy to investigate this question. In the case of tissue from normal controls, there appeared to be no evidence of damage caused by the prolamin fractions. Gliadin caused changes in E-cadherin staining in four of the five coeliac subjects. However, avenin appeared to cause similar changes in three of the five coeliac biopsy experiments. Unfortunately, cytokeratin 20 staining was too unreliable to add meaningful information to the studies.
2014: The Spectrum of Major Seed Storage Genes and Proteins in Oats (Avena sativa)
From the conclusions: Although oats are purported to be safe for celiac patients, lacking has been a complete description of the oat seed proteins in at least one specific germplasm, and then available for epitope analysis and to serve as a baseline for comparing different oat cultivars.
2014: Noncontaminated dietary oats may hamper normalization of the intestinal immune status in childhood celiac disease
This study found that a substantial fraction of pediatric CD patients seem to not tolerate oats (it looks like about 30% - ed.). This table summarizes the results.
2013: Diversity of oat varieties in eliciting the early inflammatory events in celiac disease
2011: Diversity in oat potential immunogenicity: basis for the selection of oat varieties with no toxicity in coeliac disease
2011: Immunogenicity of two oat varieties, in relation to their safety for celiac patients.
2009: Introduction of oats in the diet of individuals with celiac disease: a systematic review.
2007: Avenins from different cultivars of oats elicit response by coeliac peripheral lymphocytes.
2007: In vitro tests indicate that certain varieties of oats may be harmful to patients with coeliac disease
2004: The Molecular Basis for Oat Intolerance in Patients with Celiac Disease
This study demonstrated that some people with celiac disease do react to pure oats. The people who participated in this study were selected specifically because they believed they had reacted to oats in the past. Some of them were shown to be truly having damage from oats, while others in the study were not. (You can also read a news article about this study).
Six potentially reactive portions of the oat gluten protein were found in "Identification and Analysis of Multivalent, Proteolytically Resistant Peptides from Gluten". T cells reacted to oat gluten in a study by Kilmartin.