What is whole grain?
A kernel of grain consists of four parts: the inedible outer covering or husk, the bran, the endosperm and the germ. When these last three are present after milling, the resulting flour or meal is called “whole grain.” Whole grains are the least processed grains and contain a wealth of functional, biologically active compounds. This combination of complex carbohydrates, dietary fiber, plant protein, phytonutrients, antioxidants, vitamins and minerals offers significant health benefits.
1. What's in a whole grain?
The three parts of a whole grain — the bran, endosperm, and germ — each contain different nutrients. The layers of bran around the endosperm are rich in dietary fiber and contain between 50% to 80% of the minerals. The endosperm is high in starch and protein. The germ contains oils, vitamins, and minerals. Among this parcel of nutrients can be found: vitamin E, vitamin B6, magnesium, manganese, zinc, potassium, copper, selenium, folate, insoluble fiber, phytosterols, stanols, phytates, sphingolipids, lignans, phenolic acids, and more.(1) Many of these compounds have an antioxidant function — thus the surprising fact that a single serving of whole grain cereal has more antioxidant activity than a serving of vegetables.(2)
2. Whole grain usage and recommended intake:
USDA's Food Guide Pyramid recommends six to 11 servings of grains per day. In a 1997 Gallup national survey, Americans claimed to eat an average of only 3.2 grain servings per day — and less than one of those was a whole grain, according to researchers.(3) Several organizations, including the American Dietetic Association, the U.S. Department of Health and Human Services, and the USDA have recommended a minimum of three whole grain servings per day.
3. Whole grains as a strategy for health:
The wealth and variety of nutrients in whole grains seem to apply a unique catalyst to human health. It is now believed that the combination of these various compounds, rather than one "magic bullet" nutrient, accounts for the many health benefits associated with increased usage of whole grains.(4)
4. Whole grains and diabetes:
Results from Harvard’s Women’s Health Study showed that the incidence of diabetes was related to the consumption of whole grain. Specifically, there was a 27% reduction in risk for developing type 2 diabetes when subjects ate three daily servings of whole grain foods.(5) These findings were echoed by the Iowa Women’s Health Study which charted a 22% decline in the risk of developing type 2 diabetes amongst women who had the highest consumption of whole grains.
5. Whole grains and coronary disease (CHD):
The risk of heart disease amongst those participants in Harvard’s Nurses Study was inversely related to their consumption of whole grains — a 25% reduction in risk for those with the highest consumption of whole grains. Interestingly, the women in this group were only eating 2.7 whole grain servings per day, suggesting a big benefit for a modest dietary change.(6) A body of research has developed that supports these findings. A meta-analysis of 12 studies indicates a 26% reduction in CHD with the regular intake of whole grains.(7)
6. Whole grains and certain cancers:
There appears to be a favorable cancer connection linked to whole grain usage. A 40 study meta-analysis involving 20 cancers showed a strong relationship between eating higher levels of whole grains and lower numbers of gastrointestinal cancers. The results included a 21% lower risk for cancers of the colon, a 30% lower risk for pancreatic cancer, and a 43% lower risk for gastric cancer. The mechanism for these significant results is not known. Researchers have theorized that the protective action of whole grains is an amalgam of their antioxidant properties, carbohydrate fermentation in the bowel, decreased transit time and increased fecal bulk — these last two are due to dietary fiber which is prevalent in whole grains.8
7. Whole grains and intestinal health:
Whole grains are a particularly good source of fiber. The symptoms of constipation and diverticulitis can be reduced with a high fiber diet. Interestingly, one campaign in Australia encouraged the consumption of whole grain breads. They found that the sales of whole grain bread rose 58% and the sales of laxatives fell by 48% in the one community where the campaign was launched.(9)
8. Whole Grains Made Easy
Look closely at the shelves in your local health food or grocery store and you will notice grains such as amaranth, barley, corn (yes, popcorn is a whole grain!), millet, oats, quinoa, sorghum, triticale, brown or colored rice, wild rice, rye — and wheat, in a multitude of varieties like bulgur, Kamut®, spelt, farro and grano. All of these are considered whole grains if all three parts of the grain — the bran, the germ and the endosperm — are included.
Although whole grains may be included in foods, they also need to be in sufficient quantities to provide the desired health benefits. Health professionals now recommend that all adults eat at least half their grains as whole grains, making sure to consume at least three servings of whole grains every day.
The Whole Grains Council, a consortium of scientists, chefs and food industry executives, has introduced a new packaging symbol to help consumers find healthy whole grain foods. Shaped like a postage stamp, in eye-catching black and gold, this symbol has three versions.
The ‘Good Source’ stamp identifies foods containing a half serving of whole grains. The ‘Excellent Source’ stamp appears on foods containing a full serving of whole grains, and the ‘100% Excellent Source’ stamp denotes foods with a full serving of whole grains and no refined grains.
Whole Grain Stamps make getting three servings a day simple. Just look for three foods with an Excellent stamp, or six foods with a Good stamp, and you can be sure you’re getting at least three servings worth of whole grains. You can learn more about the delicious taste and health benefits of whole grains at the Council’s website at
www.wholegrainscouncil.org
.
Sources
1. Jones JM, et al. “The Importance of Promoting a Whole Grain Foods Message.” Journal of American College of Nutrition, 2002;21:4:293-297.
2. Miller HE, Rigelhof F, Marquart L, Prakash A, Kanter M. “Whole grain products and antioxidants.” Cereal Foods World, 2000;45:59-63.
3. Miller HE, Rigelhof F, Marquart L, Prakash A, Kanter M. “Antioxidant content of whole grain breakfast cereals, fruits, and vegetables.” Journal of American College of Nutrition, 2000;19:312S-319S
4. Slavin JL, Martini PC, Jacobs D, Marquart, L. “Plausible mechanisms for protectiveness of whole grains.” American Journal of Clinical Nutrition, 1999;70:459S-463S.
5. Liu S, Manson JE, Stampfer MJ, et al. “A prospective study of whole grain intake and risk of type 2 diabetes mellitus in U.S. women.” American Journal of Public Health. 2000;90:1409-1415.
6. Liu S, Stampfer MJ, et al. “Whole grain consumption and risk of coronary heart disease: results from the Nurses Health Study.” American Journal of Clinical Nutrition. 1999;70:412-419.
7. Anderson JW, Hannah TJ, Peng X, Kryscio RJ. “Whole grain foods and heart disease risk.” Journal of American College of Nutrition, 2000;19:291S-299S.
8. Jacobs DR, Marquart L, Slavin J, Kushi L. “Whole grain intake and cancer: An expanded review and meta-analysis.” Nutr Cancer, 1998;130:85-96.
9. Liebman B. “The Whole Grain Guide.” Nutrition Action Health Letter, Mar. 1997
10. Brandt LA. “Prebiotics enhance gut health.” Prepared Foods, 2001, Sept.
11. Quinoa Corporation,
www.quinoa.net
12. The Mayo Clinic, University of California Los Angeles, Dole Co. Encyclopedia of Foods: A Guide to Healthy Nutrition,
Academic Press, San Diego, 2002.
13. Baltensperger DD, Drew JL, Lenis AN, Corr A. Amaranth Grain Production in Nebraska. University of Nebraska-Lincoln, 1991
14. Crops Gallery — Finger Millet
