Rye flour is a popular baking ingredient due to its nutritional value and variety of historic and culinary uses. Rye flour was the staple diet for ancient civilizations; today it is used for several cooking traditions. During ancient times, bread and other wheat products were the major source of sustenance for humankind. Archaeological evidence attests to the fact that man started cultivating and growing cereals at least 9 thousand years ago. The development of barley and wheat, which came later, was an agricultural revolution triggered by new livestock production technologies.
Though rye flour lacks the protein and vitamin E of whole-grain wheat, it does contain significant amounts of B vitamins, iron, and zinc. Unlike whole grains, rye flour does not contain complex carbohydrates but does contain some carbohydrates that come from starches.
Another reason why rye flour is a popular ingredient in bread recipes is that it contains less gluten than wheat flour, which helps decrease the risk of developing celiac disease, a common affliction suffered by people with gluten allergies.