Along with fruits and vegetables, dairy and protein, grains constitute one of the four major food groups. According the the U.S. Department of Agriculture's MyPlate dietary guideline, grains should make up approximately one-quarter of your daily meals. Of these grains, the USDA recommends that at least half are whole grains, or those that have not been through a refining process. By following these guidelines and eating plenty of whole grains, you can improve your cardiovascular, digestive and overall health.
Cereal Grains
In the 2010 "Dietary Guidelines for Americans," the USDA and U.S. Department of Health and Human Services define "grains" as the edible fruit seeds of grass crops or foods primarily consisting of these seeds. Among the most common, they list barley, buckwheat, bulgur, corn, popcorn, millet, quinoa, rice, rye, oats, wheat and wild rice. According to the Food and Agriculture Association of the United Nations, other common grains include amaranth, maize, sorghum, teff, triticale, fonio and a variety of wheat relatives, including durum, einkorn, spelt and emmer.
Whole Grains
Whole grains are either unrefined cereals or foods primarily consisting of unrefined cereals. Not having been through the refining process, whole grains have their husks intact. Made up of the germ and bran layers, the husk is traditionally stripped from grains in the milling process. Removing these layers lowers a grain's fiber content, thus reducing its cardiovascular and digestive benefits. In addition, the milling process removes much of the mineral content of whole grains. This includes selenium, magnesium and potassium, all of which are vital to digestive, muscular, cardiovascular and overall health.
Refined Grains
In contrast with whole grains, refined grains are the remnants of cereals after the milling process. Without their outer husk, these grains have a longer shelf life and smoother, softer texture. This makes these grains ideal for use in baking and bread-making, with white flour and refined cornflour common in pastries, breads, tortillas and other baked goods. While whole grains are commonly eaten on their own, refined grains are more common as ingredients in other foods. A notable exception to this is white rice, a staple food throughout the world that is the product of refining brown rice.
Enriched Grains
To replace some of the nutrients missing in refined grains, food processors commonly add vitamins and minerals to grain after the refining process. According to the Mayo Clinic, most grains go through enrichment after refining, and some countries require this by law. Enrichment involves replacing nutrients that naturally occur in the husk, such as B vitamins, potassium, selenium and magnesium. Despite the addition of these vitamins and minerals, however, the enrichment process does not replace the fiber lost in the milling process. As whole grains are naturally high in vitamins, minerals and fiber, you should always try to choose whole grains over enriched or other refined grains.
References
- U.S. Department of Agriculture: Choose My Plate
- MayoClinic.com: Whole Grains: Hearty Options for a Healthy Diet
- "Dietary Guidelines for Americans: Seventh Edition"; U.S. Department of Agriculture and U.S. Department of Health and Human Services; 2010
- "Cereals, Pulses, Legumes and Vegetable Proteins: First Edition"; Food and Agriculture Organization of the United Nations; 2007
- American Heart Association; Whole Grains and Fiber; January 2011
- University of Maryland Medical Center: Potassium
