Testing for Gluten Contamination (Page 2)

Must Read Study Courtesy of Quaker on Testing Oats for Gluten

Gluten-containing grains skew gluten assessment in oats due to sample grind non-homogeneity. Fritz RD, Chen Y, Contreras V. Food Chemistry. February 2017;216:170-175. Published online ahead of print August 12, 2016.

Disclosure: The authors declare that they have no competing interests. Ronald D. Fritz, Yumin Chen, and Veronica Contreras are salaried employees of PepsiCo Inc. or Quaker Foods and Snacks (QFS), a subsidiary of PepsiCo, Inc., which funded this research. QFS has a commercial interest in gluten-free foods.


What follows is a […]

Nima, the Portable Food Testing Device

Published 8/5/2016

Gluten Free Watchdog receives at least one question each week about Nima asking our opinion on the testing device. Included below is the email sent to subscribers to GFWD in June. You also may be interested in listening to a GFWD video about some of the complexities associated with testing food for gluten. It is available HERE.

Nima: Many of you continue to have questions about Nima, the portable food testing device in development by 6 Sensor Labs. GFWD […]

Gluten Content of Gluten Digestive Enzyme Supplements: A Very Brief Summary

This is not a commentary about whether individuals with gluten-related disorders should use gluten digestive aids or whether there is any benefit to these supplements. For an excellent article on enzymes and current medical thinking, please see the interview conducted by NFCA available HERE. 

As many of you know Gluten Free Watchdog has been sending various “glutenase” enzyme supplements to the lab for gluten testing. Initial results were very troublesome. But based on additional testing following a modified testing protocol, […]

Green Tea & Possible Gluten Contamination

Many of you may have heard about an FDA study published in June entitled, “Survey of Tea for the Presence of Gluten.” Scientists at the Food and Drug Administration conducted this study. What follows is a brief summary of the situation.

Background: A health care professional recently sent out a mass email with a link to the aforementioned study abstract on PubMed. The email suggested (in my opinion) that gluten contamination found in the study was coming from the tea […]

Gluten Contamination in Labeled Gluten-Free Foods

Gluten Contamination in Labeled Gluten-Free Foods

The good news: Three studies on gluten contamination in labeled gluten-free foods have been published in the past few weeks.

The bad news: The findings are wildly different.


Study One:

Girdhari M. Sharma, Marion Pereira, Kristina M. Williams. Gluten detection in foods available in the United States – A market Survey. Food Chemistry 169 (2015) 120–126. (Published online ahead of print)

Note: Study authors are from the Food and Drug Administration.

Number of labeled gluten-free foods tested: 275; Food […]

Five Percent of Tested Foods Making Gluten-Free Claims are not Gluten-Free Study Finds

For Immediate Release

Five Percent of Tested Foods Making Gluten-Free Claims are not Gluten-Free Study Finds

Three years of testing data from Gluten Free Watchdog Published

Thompson T, Simpson, S. A comparison of gluten levels in labeled gluten-free and certified gluten-free foods sold in the United States. European Journal of Clinical Nutrition advance online publication, 1 October 2014; doi:10.1038/ejcn.2014.211



October 1, 2014 Under the Food and Drug Administration’s gluten-free labeling rule, food labeled gluten-free must contain less than 20 parts per million of gluten. In […]

Update on the gluten-free status of yeast extract

Update July 29, 2014 : Based on testing done by Gluten Free Watchdog, I would like to reiterate that it is my recommendation that individuals with gluten-related disorders avoid products NOT labeled gluten-free containing the ingredients yeast extract or autolyzed yeast extract unless the source is confirmed. Please note that if you live in Canada, ALL gluten sources must be declared in the ingredients list. In addition Coeliac UK recently modified their position on yeast extract specifically as it […]

Gluten Contamination of Gluten-Free Foods Sold in the US

Thomas Grace and I recently published two years worth of testing data from Gluten Free Watchdog in the journal Practical Gastroenterology. The pdf is available here.

Excerpt: The Food and Drug Administration (FDA) recently released the long awaited rule
on the labeling of food as gluten-free. Labeled gluten-free food regulated by the FDA
and sold in the United States must contain less than 20 parts per million (ppm) of
gluten. The objective of this evaluation is to assess the actual gluten content of labeled
gluten-free […]