- Many grains, flours, and starches are naturally gluten-free including (but not limited to):
- Wild rice
- Naturally gluten-free grains, flours, and starches may become contaminated with wheat, barley, and rye while being:
- Grown if wheat, barley, or rye is grown in a field next to a gluten-free grain or if a gluten-free grain is grown in rotation with wheat, barley, or rye.
- Harvested if the same equipment is also used to harvest wheat, barley, or rye.
- Transported if the railcar, truck, etc was previously used to transport wheat, barley, or rye.
- Processed if the same equipment is also used to process wheat, barley, or rye.
- Stored if gluten-free grain is kept in close proximity to gluten-containing grain.
- To decrease your chances of eating gluten-free grains and flours contaminated with wheat, barley, or rye it is recommended that you:
- Buy grains, flours, and starches that are labeled gluten-free.
- Buy products made with gluten-free grains, flours, and starches that are labeled gluten-free.
- As you can see from this table, labeled gluten-free flours may contain less gluten contamination than gluten-free flours not labeled gluten- free. 2,3
GLUTEN CONTENT LABELED/UNLABELED GLUTEN-FREE FLOURS:
||MEAN PPM GLUTEN LABELED GLUTEN FREE
||MEAN PPM GLUTEN NOT LABELED GLUTEN FREE
||305 ppm, 327 ppm
||< 5 ppm
||< 5 ppm
||< 5 ppm
||92 ppm, 2925 ppm
References: Thompson, Lee, Grace. JADA 2010: 110; 937-940; Gluten Free Watchdog, LLC www.glutenfreewatchdog.org
TAKE HOME MESSAGES:
- Naturally gluten-free grains, flours, and products made from them may be contaminated with wheat, barley, or rye.
- Buy labeled gluten-free products whenever possible to decrease your risk of consuming contaminated products.
RESOURCES FOR YOU:
Gluten-Free Dietitian. Contamination of Naturally Gluten-Free Grains. http://www.glutenfreedietitian.com/newsletter/contamination-of-naturally-guten-free-grains/ . Accessed November 3, 2011.
Gluten-Free Dietitian. Contamination of Naturally Gluten-Free Grains: Part 2.http://www.glutenfreedietitian.com/newsletter/contamination-of-naturally-gluten-free-grains-part-2/ . Accessed November 3, 2011.
- Celiac Disease Toolkit. American Dietetic Association. Chicago, IL, 2011.
- Thompson T, Lee AR, Grace T. Contamination of naturally gluten-free grains, seeds, and flours in the United States: A pilot study. J Am Diet Assoc. 2010;110:937-940.
- Gluten Free Watchdog. www.glutenfreewatchdog.org . Accessed November 3, 2011.
Revision Date: 8-29-12
Author: Tricia Thompson, MS, RD
Editors: Melinda Dennis, MS, RD, LDN and Daniel Leffler, MD, MS