Grains have often been called the "staff of life" due to the significant role they've played in human diets through the millennia. Grains and grain flours are full of nutrients important for good health, but they're even better for you if left whole or unprocessed. Research has discovered that whole grains may even help prevent or treat certain chronic diseases.
Identification
Grains are the seeds of grasses and range in size from large popcorn kernels to small quinoa seeds. Other examples include barley, brown rice, buckwheat, bulgur, millet, oatmeal, whole-wheat and wild rice. Whole grains consist of a tough fibrous outer layer called bran that protects the inside of the kernel, where the starchy endosperm resides. The endosperm provides energy for the germ, the seed's reproductive kernel, full of vitamins, minerals and unsaturated oils.
Significance
Mills in the 19th century changed the way we eat grains, removing the bran and germ and along with them, more than half of B vitamins, 90 percent of the vitamin E, 25 percent of protein, at least 17 key nutrients and virtually all of the fiber, according to the Harvard School of Public Health and the Whole Grain Council. Consumer demand for more whole-grain products has led to the introduction of more such products into the marketplace, including 86 new whole-wheat products in 2007 alone, although that still constitutes only 4 percent of all wheat products, reports the World's Healthiest Foods website.
Misconceptions
White whole-wheat breads may not look like they contain whole grains, but they're actually made with an albino variety of wheat and retain the same nutritional benefits as regular whole-grain bread. Some highly processed grain-flour products are colored brown with an ingredient such as molasses and made to look like whole grain, although they aren't. If you see words like "wheat," "durum," or "multigrain" on a product, it doesn't guarantee that the product is whole grain. If there are two grain ingredients and only the second is listed as whole grain, the product may contain as little as 1 percent or up to 49 percent whole grain. The words "enriched flour," "degerminated," "bran," or "wheat germ" do not refer to whole grain flours.
Nutrition
Walter Willett, chairman of the nutrition department at the Harvard School of Public Health, says that whole grains contain micronutrients like fiber, folic acid, magnesium and vitamin E. Other nutritional benefits include antioxidants, lignans, phenolic acids, phytoestrogens and phytochemicals. The Mayo Clinic adds that a slice of commercially prepared white bread averages 66 calories, 1.9 g protein and 0.6 g of fiber, whereas a slice of bread made from whole-grain flour has 69 calories, 3.6 g protein and 1.9 g of fiber.
Benefits
Whole grains contain high levels of fiber that can help prevent constipation and diverticular disease. The antioxidants in whole grains prevent LDL cholesterol from reacting with oxygen, a step that leads to cholesterol-clogged arteries. Plant estrogens and minerals in whole grains may help protect against some cancers and diabetes.
Expert Insight
The 17-year Iowa Women's Health Study published in the 2007 "American Journal of Clinical Nutrition" found that women who ate the most servings of foods made from whole grains and whole grain flours were 30 percent less likely to have died from an inflammation-related condition. The long-term Framingham Offspring Study discovered that increased intakes of whole grains can reduce your risk for metabolic disorders including type 2 diabetes. Research extracted from the Harvard-based Nurses' Health Study and published in 1999 in the "American Journal of Clinical Nutrition" determined that women who ate two to three servings of whole-grain products daily were 30 percent less likely to have a heart attack or die from heart disease over a 10-year period than women who ate less than one serving per week. Although studies are mixed on the effects of whole grains in preventing cancer, the large five-year NIH-AARP Diet and Health Study suggests that eating whole grains offers some protection against colorectal cancer.
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