Testing for Gluten Contamination (Page 4)

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 […]

Standards for testing food for gluten: Issues that need addressing

We all know that food labeled gluten-free should be tested for gluten. Some of us are familiar with the tests that should be used to assess gluten content. But most of us don’t know how tricky it actually is to test for gluten. This blog is meant to start a conversation by pointing out the lack of standards when it comes to gluten assessment.


There are a lot of “shoulds” when it comes to testing food for gluten. Unfortunately just […]