Naturally gluten free foods not always gluten free
Reuters Health (Jul 2010 - "Gluten-free" foods may be contaminated: study) have reported that in a small study testing natually gluten free foods 41% of those tested may be contaminated with gluten.
The foods chosen were not specifically labelled as gluten free and were chosen from naturally gluten free grains, seeds and flours freely available on grocery store shelves. While only 22 samples were tested 41% were found that may have been contaminated with gluten. The products were tested for the amount of gluten they contained against a proposed Food and Drug Administration limit for any product labeled gluten-free, 20 parts contaminant per million parts product.
Seven of the 22 products wouldn't pass the FDA's gluten free test with one product, a type of soy flour, having a gluten content of almost 3,000 parts per million. Other products containing gluten included millet flour, millet grain, buckwheat flour and sorghum flour.
Cynthia Kupper, Executive Director of the Gluten Intolerance Group of North America is quoted as saying this is "a red flag" for patients. People with wheat allergy or intolerance as well as people with coeliac disease could suffer reactions as a result of eating these naturally gluten free foods. Even companies that do explicitly label their products as gluten-free, she said, might not always test products they assume won't contain any gluten.
Although this study is very small in size it does mean that people requiring a wheat free or gluten free diet cannot automatically assume that a product is wheat or gluten free unless it is marked "wheat free" or "gluten free" on the packaging.