Oat vary among oat varieties. Also, oats products are frequently cross-contaminated with other gluten-containing cereals during grain harvesting, transport, storage or processing. Pure oats contain less than 20 parts per million of gluten from wheat, barley, rye, or any of their hybrids. Use of pure oats in a gluten-free diet offers improved nutritional value from the rich content of oat protein, vitamins, minerals, fiber, and lipids, but remains controversial because a small proportion of people with celiac disease react to pure oats. Some cultivars of pure oat could be a safe part of a gluten-free diet, requiring knowledge of the oat
Rye a serious medical condition known as ergotism. Ergotism can cause both physical and mental harm, including convulsions, miscarriage, necrosis of digits, hallucinations and death. Historically, damp northern countries that have depended on rye as a staple crop were subject to periodic epidemics of this condition. Such epidemics have been found to correlate with periods of frequent witch trials, such as the Salem witch trials in Massachusetts in 1692. Rye grain is refined into a flour. Rye flour is high in gliadin but low in glutenin. It therefore has a lower gluten content than wheat flour. It also contains a higher