How can gluten, a protein from a naturally occurring foodstuff, be harmful?
First, it must be understood that the gluten-containing grains we eat today are actually domesticated and now genetically hybridized versions of what originally were wild grasses endemic to the Tigris-Euphrates river basin. Presumably, due to pressures from shortages of other foods, or ingenuity of ancient peoples, these grasses became a source of food and calories. Learning how to cultivate and farm these and other plants alleviated the pressures of the hunting/gathering lifestyle, paving the way for more abundant and readily available food, which in turn, paved the way for the more stable and populated Agrarian societies that followed. It is believed and seems sensible, that this shift to agriculture-based societies was responsible for the flourishing (note the word flour in flourishing) civilizations of Mesopotamia and Egypt that followed.
