Gluten peptides in gluten-reduced barley beer
What it found
Barley-based beers treated to remove gluten can still contain gluten peptides that may trigger immune reactions in people with coeliac disease.
It is not yet clear whether these peptides cause harm when drunk, because they may break down during digestion.
What they found
Studies in people
Clinical gluten limits
A study in adults with coeliac disease found that some had worsening of small intestinal damage after 10 mg gluten per day for 90 days, while others improved on 50 mg per day. The authors of that study said gluten intake should stay below 50 mg per day.
Animal and lab studies
Digestion may reduce peptides
One study found that polypeptides from gluten-reduced beers that could trigger an immune response were greatly reduced after simulated stomach and duodenal digestion.
Other findings
Peptides in treated beer
Beers made from barley and treated with enzymes to remove gluten can still contain gluten peptides. Some of these peptides may be immunotoxic to people with coeliac disease.
Detection methods vary
Different test kits for gluten give different results for the same beer sample. No antibody test covers all gluten epitopes that matter for coeliac disease.
Mass spectrometry findings
In 12 commercial beers marketed as reduced gluten or gluten free, mass spectrometry found gluten fragments. In several, levels were similar to untreated control beers.
Unknown epitopes
The known list of 38 gluten T-cell epitopes can only account for the reactivity of 50% of gluten-specific T cells from coeliac patients. Many epitopes remain unidentified.
What the authors conclude
“Based on current knowledge it is difficult to assess whether barley-based gluten-free beer is safe for consumers with coeliac disease.”
Also in their conclusions
- They say it is difficult to assess whether barley-based gluten-free beer is safe for consumers with coeliac disease based on current knowledge.
- They recommend future progress requires in vivo toxicity assessments of the degraded proteins in coeliac disease patients, development of standardised gluten-free production strategies, and appropriate reference materials and calibrators.
- They state that clinical feeding studies with small-bowel histology are the best approach to establish adverse clinical effects.
How it was done
People with coeliac disease must avoid gluten for life, so accurate labelling matters. Recent reports suggest that beers labelled gluten-free may still contain peptides that could be immunotoxic.
The authors reviewed published studies on the presence, levels and immune effects of gluten peptides in barley beers treated to reduce gluten. They also examined how these beers are made, how gluten is measured, and what current limits mean.
What it can’t tell you
- This is a review of published studies, not a new experiment. It cannot show what happens in people who drink these beers.
- The immune effects of gluten peptides in beer have mostly been studied in lab tests, not in people with coeliac disease.
- It is not known whether the gluten peptides found in beer actually reach the gut immune system and cause harm when consumed.
Who paid
- Conflicts
- Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
- Authors work at
- Joint Research Centre (JRC), Belgium; Technical University of Denmark, Denmark; Leibniz Institute for Food Systems Biology at the Technical University of Munich, Germany
The paper
- Title
- Barley based gluten free beer - A blessing or an uncontrollable risk?
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Cubero-Leon E, Madsen CB, Scherf KA, et al (2024). Barley based gluten free beer - A blessing or an uncontrollable risk?. Food and chemical toxicology. doi:10.1016/j.fct.2024.115019Free full textPubMed 39307344DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error