Courtesy National Newsletter
Members have asked a number of questions recently about low gluten beer. A number of vendors offer these beers that are made with malt but are treated to reduce the gluten content using enzymes that break down the barley proteins into small pieces. Various companies claim that their beer tests to less than 20 ppm, less than 10 ppm, and less than 3 ppm gluten. Is it really safe for someone with celiac disease to drink?
The CCA does not have a formal position on these beers, but we do have concerns about the accuracy of the test results. Hordeins, the gluten proteins in barley, are complicated to detect, especially when these proteins are partially hydrolyzed or broken down into pieces as they are in beer.
The most common test for hordeins (the R5 Sandwich ELISA) looks for two specific sites on the protein. When many of the proteins are broken, the test may miss finding the hordein if the protein breaks near the binding site [Note 1]. Some of the fragments of proteins may still cause damage in someone with celiac disease.
Researchers in Australia [Note 2] tested a number of low-gluten beers using a different tool, mass spectrometry, and they found significant amounts of gluten protein and gluten protein fragments in all of the low gluten beers they tested. With a sample size of 60 beers selected from the international market, underestimating the amount of gluten in low-gluten beer is probably a significant issue worldwide.
Good news? The researchers did not find gluten in any of the gluten-free beers made without barley malt. Cheers!
Note 1: For more information about testing for barley, check http://www.glutenfreedietitian.com/newsletter/barley-malt-ingredients-in-labeled-gluten-free-foods/.
Note 2: Colgrave ML, Goswami H, Howitt CA, Tanner GJ. What is in a beer? Proteomic characterization and relative quantification of hordein (gluten) in beer. J Proteome Research. October 2011. The study is available at: http://pubs.acs.org/doi/suppl/10.1021/pr2008434