Abstract:  Cereal grains can contribute to maintain health and prevent chronic diseases by supplying biologically active components. The exact mechanism of action of these components is not completely understood,but extensive evidence suggests the antioxidants that are present in the grains are the likely source of benefits. These activities or properties might protect against coronary heart disease and diabetes. The relationships of complex carbohydrates,whole grain products and the prevention of diseases,including type2 diabetes mellitus and coronary heart disease continue to challenge the scientific community. Though cereal grains contribute to a healthy diet there are some people that can not tolerate the proteins present in the grain. This can lead to food allergies and when severe can be diagnosed as celiac disease.