Healthy Diet: Whole grains

By: Alere Staff

You may have heard a lot about whole grains lately, and that you should be eating more as part of a healthy diet. But, what exactly are whole grains? How much should you eat? And what makes them healthy?

All types of grains, especially whole grains, are part of a healthy diet. Grains are good sources of complex carbohydrates and key vitamins and minerals. Grains are also naturally low in fat. The 2010 Dietary Guidelines for Americans recommends that at least half of the grains you consume be whole grains.1 You may already be consuming grains as part of your daily diet, but are they whole grains?

Whole, Refined, and Enriched Grains: What’s the difference?2

Whole grains include the entire grain seed, called the kernel. This consists of the bran, the germ and the endosperm. The grain can be cracked, ground, or flaked, but to be considered a whole grain, it must retain the same proportions of bran, germ, and endosperm. Some examples include wheat, oatmeal, whole-grain cornmeal, brown rice, whole-grain barley, whole rye, and buckwheat.

Refined grains have been milled to remove the bran and germ from the grain to give grains a finer texture and improve their shelf life. This process removes dietary fiber, iron, and many B vitamins. Some examples include white flour, found in some breads and pastas.

Enriched grains are grain products with B vitamins (thiamin, riboflavin, niacin, folic acid) and iron added after the milling process. Most refined-grain products are enriched.

Why are whole grains considered part of a healthy diet?

Whole grains are good sources of fiber and other important nutrients, such as vitamin B, vitamin E, selenium, potassium and magnesium. As researchers look more closely at the types of foods people consume, they are learning that the quality of the food is as important as the quantity.

Eating more whole grains lowers total cholesterol, low-density lipoprotein (LDL, or bad) cholesterol, triglycerides, and insulin levels. Reducing any of these would be expected to reduce the risk for cardiovascular disease.3 In a recent study, women who ate 2 to 3 servings of whole-grains each day 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 1 serving per week.4 Consuming the recommended amount of whole grains has also been shown to reduce the risk of stroke.5, 6

Daily Intake of Whole Grains

According to the 2010 Dietary Guidelines for Americans, less than 5 percent of Americans consume the minimum recommended amount of whole grains. The recommended daily amount is about 3 ounce-equivalents per day. In general, 1 slice of bread, 1 cup of ready-to-eat cereal, or ½ cup of cooked rice, cooked pasta, or cooked cereal can be considered as 1 ounce equivalent. These guidelines are published every 5 years by the U.S. Department of Health and Human Services and the U.S. Department of Agriculture.1

The recommendation to consume at least half of total grains as whole grains can be met in a number of ways. Talk to your doctor about your diet and ways to increase your whole grain consumption.

Do whole grains interact with warfarin?

There has been little research done on eating whole grains while taking warfarin. You may want to be pay attention to the amount of vitamin K in specific whole grain products. Depending on the type of whole grain product you choose, there may be added ingredients, like vegetables, spices, etc., that may affect the amount of vitamin K. Like anything else you eat, when you are on warfarin, you need to have a consistent diet. For additional information about the vitamin K content in foods and beverages, visit our Vitamin K Finder.

  1. Dietary Guidelines for Americans, 2010 (Released 1/31/11).
  2. Dole Food Company, et al. Encyclopedia of Foods: A Guide to Healthy Nutrition. San Diego, Calif. Academic Press; 2002.
  3. Mellen PB, Walsh TF, Herrington DM. Whole grain intake and cardiovascular disease: A meta-analysis. Nutr Metab Cardiovasc Dis. 2007.
  4. Liu S, Stampfer MJ, Hu FB, et al. Whole-grain consumption and risk of coronary heart disease: results from the Nurses’ Health Study. American Journal of Clinical Nutrition. 1999; 70:412-9.
  5. Simin Liu, et al. Whole Grain Consumption and Risk of Ischemic Stroke in Women: A Prospective Study. JAMA. 2000;284(12):1534-1540.
  6. Jeerakathi, T.J., Wolf, P.A. Prevention of strokes. Current Atherosclerosis Reports. 2001, Volume 3, Issue 4, pp 321-327.