"A study that measured contamination by gluten tested 22 single-ingredient inherently gluten-free grains, seeds and flours, and found 32% of these products contained >20 ppm gluten and one product contained 2,925 ppm of gluten. The products tested that were positive for gluten included soy, millet, buckwheat, rice and sorghum flour. This is sufficient gluten to cause on-going symptoms in many celiac disease individuals.[1]"
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