The question has been raised as to whether naturally gluten-free grains and flours labeled organic but not gluten-free are likely, because of their organic status, to contain less than 20 parts per million of gluten. In my experience the answer is NO. In other words, you can not rely on an organic label (in lieu of a gluten-free label) to determine whether a naturally gluten-free grain or flour is contaminated with gluten.

I have been involved in 2 studies that assessed gluten contamination of naturally gluten-free grains NOT labeled gluten-free. The first study assessed oats and the most recent study assessed a wide variety of gluten-free grains, seeds, and flours.

In the oat study (Thompson, T. Gluten Contamination of Oat Products in the United States. New England Journal of Medicine 2004;351:2021-2022), 4 lots of 3 brands of oats not labeled gluten-free were tested for gluten contamination. The 3 brands were Quaker, Country Choice, and McCann’s. Country Choice was the only product labeled organic. The mean gluten content per lot in parts per million was 210, 131, 120, and less than 3 (the limit of detection for the assay used).

In the grain study (Thompson T, Lee AR, Grace T. Gluten Contamination of Grains, Seeds, and Flours in the United States: A Pilot Study. J Am Diet Assoc. 2010;110:937-940), 7 of 22 naturally gluten-free grains and flours not labeled gluten-free were contaminated with gluten in excess of 20 parts per million. Of these 7 products, 6 were labeled organic (data not previously published). These products were:

Millet flour, organic, mean ppm gluten 305

Millet flour, organic, mean ppm gluten 327

Millet grain, organic, mean ppm gluten 25

Buckwheat flour, not labeled organic, mean ppm gluten 65

Sorghum flour, organic, mean ppm gluten 234

Soy flour, organic, mean ppm gluten 2925

Soy flour, organic, mean ppm gluten 92

Looking at this data in another way, of the 22 products tested, 11 products were labeled organic; 11 products were not. Of the 11 products labeled organic, 6 contained gluten above 20 parts per million. Of the 11 products not labeled organic, 1 contained gluten above 20 parts per million.

Bottom Line: There are specific rules governing the use of the term “organic” on a food label but testing for gluten is not one of them.

The following information has been published previously in one of my posts, but it is worth reprinting here. This is what one manufacturer of gluten-free oats does to ensure their product is gluten-free…

“Cream Hill contracts directly with seed growers who are certified by the Canadian Seed Growers Association and who are steadfast in protecting the oats from cross-contamination with other grains during planting, growth, harvest, transport and storage. (Purity is the name of the game in the seed-growing industry). Their fields have been wheat-, barley- and rye-free for at least three years before our oats are planted. Seed to be planted is checked for contaminating grains by a certified seed laboratory. The Canadian Food Inspection Agency inspects the crop during growth for the possible presence of contaminating grains. Only dedicated or thoroughly-cleaned equipment is used. At harvest, the seed that will be used for rolled oats and oat flour is checked by the seed lab for the presence of contaminating grains.”

“Our processor’s dedicated mill is certified gluten-free (as is Cream Hill’s packaging facility) by the Gluten-Free Certification Organization (GFCO) in Seattle. Finally, after milling into rolled oats and oat flour our products are tested for gluten using the state-of-the-art R5-ELISA method (the validated Ridascreen Gliadin R-7001 test kit not to be confused with the Ridascreen Fast Gliadin R-7002 test kit). All testing is done by outside independent laboratories. Between November 2005 and May 210, we have tested 248 lot numbers. 215 lot numbers (86.7%) have tested below the limit of quantification of 5 ppm gluten; 21 lot numbers (8.5%) tested between 5 and 9.9 ppm gluten; 11 lot numbers (4.4%) tested between 10 and 19.9 ppm; and 1 lot number tested at or above 20 ppm gluten and was donated to a food bank for use as regular oats.”

This very careful, tedious, and necessary process is why we all pay more for labeled gluten-free oats and other labeled gluten-free products that undergo a similar process.

Copyright © by Tricia Thompson, MS, RD

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Organic grain and gluten contamination