The whole grain kernel is composed of three main parts—the starchy endosperm, outer bran, and germ. The outer bran and germ, rich in nutrients, insoluble fibers, and antioxidants, are removed during the milling process to create the refined flours and grains that are the basis of many baked and processed foods. Thus, individuals should replace refined grains in their diet with whole grains as much as possible. The 2015 Dietary Guidelines for Americans recommend that at least half of all grains eaten are whole grains. It is well established that whole grains are linked to many health benefits, including decreased risk of mortality, heart disease, stroke, type 2 diabetes, and cancer. In addition to eating more whole grains, it is important to eat a variety of different whole grains, as different grains are linked with different health benefits. For example, wheat is rich in the nutrients magnesium and potassium. Rye, while rich in potassium, is also rich in the nutrient manganese. Wheat and rye are both rich in arabinoxylan, known for high antioxidant activity. Oats are rich in the soluble fiber β-glucan. The greater the variety in nutrients, fibers, and antioxidants, the greater the health benefits!
Nicola M. McKeown, Ph.D.
Scientist I, Nutrition Epidemiology Program – Jean Mayer USDA HNRCA
Associate Professor – Friedman School of Nutrition Science and Policy, Tufts University