Whole grains receive much attention for their health benefits, but what exactly are whole grains, and why are they so nutritious?
A whole grain is a grain kernel that contains the entire seed of the plant as it exists in nature. The seed is made up of the bran, germ and endosperm. When a grain is refined (e.g. white bread) some of the germ and most of the bran is removed, resulting in a loss of healthful components such as fiber, B vitamins, vitamin E, trace minerals and unsaturated fat.
A whole grain can be a complete food, such as oatmeal, brown rice or popcorn, or used as an ingredient in food, such as whole-wheat flour in bread or cereal. Types of whole grains include whole wheat, whole oats/oatmeal, whole grain corn, brown rice, buckwheat, millet and quinoa.
To confirm that a product contains whole grains, check the ingredient list. Be sure that specific whole grains are listed, such as whole-wheat flour or whole oats. Although the ingredient list does not include the amount of whole grain in the food, the earlier it is listed, the greater the amount.
Whole Grains and Health Benefits
Research has shown that a diet rich in whole grains is linked to a decreased risk of heart disease, type 2 diabetes, obesity, cancer and mortality.1-4 For this reason, the World Health Organization and many other health organizations recommend including whole grains as part of a balanced diet.
Although whole grains are often a good source of dietary fiber, it is not the fiber alone that provides health benefits. It is the combination of everything, including the fiber, vitamins, minerals, phytonutrients and antioxidants.
Whole Grains and Weight
Research also suggests that a balanced diet rich in whole grains can help with weight loss and maintaining a healthy body weight. In a review of observational studies, both BMI and waist circumference were found to be lower among people who consume high levels of whole grain.5 In addition, people who eat whole grains have a lower risk of gaining weight over time. For example, results from a study performed in over 27,000 men found that an increased intake of whole grains—the equivalent of less than two slices of bread per day—was inversely related to weight gain.6 These results are not only seen in men. In a 12-year study following nearly 75,000 female nurses, weight was consistently lower in the women who consumed more whole grains.7
Why might whole grains be helpful for weight management? One reason is that whole-grain products are often high in fiber which can promote fullness, allowing for a decreased intake at meals and a longer period of time between meals.8
|The Weight Watchers Approach|
The role of whole grains and their health benefits are recognized in the Good Health Guidelines. Weight Watchers recommends choosing whole-grain foods whenever possible and trying to make at least half of the grains consumed whole grains.
Other Science Library Topics
1 Ye EQ, Chacko SA, Chou EL, et al. Greater whole-grain intake is associated with lower risk of type 2 diabetes, cardiovascular disease, and weight gain. J Nutr. 2012 Jul;142(7):1304-13.
2 NM, Hruby A, Saltzman E, et al. Weighing in on whole grains: Evidence linking whole grains to body weight. Cereal Foods World. 2012;57:20-7.
3 Jacobs DRJ, Andersen LF, Blomhoff R. Whole-grain consumption is associated with a reduced risk of noncardiovascular, noncancer death attributed to inflammatory diseases in the Iowa Women's Health Study. Am J Clin Nutr. 2007 Jun;85(6):1606-14.
4 Jonnalagadda SS, Harnack L, Liu RH, et al. Putting the whole grain puzzle together: health benefits associated with whole grains—Summary of American Society for Nutrition 2010 Satellite Symposium. The Journal of nutrition." J Nutr. 2011 May;141(5):1011S-22S.
5 Harland JI, Garton LE. Whole-grain intake as a marker of healthy body weight and adiposity. Public Health Nutr. 2008 Jun;11(6):554-63.
6 Koh-Banerjee P, Franz M, Sampson L, Liu S, Jacobs DR Jr, Spiegelman D, Willent W, Rimm E. Changes in whole-grain, bran, and cereal fiber consumption in relation to 8-y weight gain among men. Am J Clin Nutr. 2004 Nov;80(5):1237-1245.
7 Liu S, Willet WC, Manson JE, Hu FB, Rosner B, Colditz G. Relation between changes in intakes of dietary fiber and grain products and changes in weight and development of obesity among middle-aged women. Am J Clin Nutr. 2003 Nov;78(5)920-927.
8 Whole grain consumption and weight gain: a review of the epidemiological evidence, potential mechanisms and opportunities for future research. The Proceedings of the Nutrition Society." Proc Nutr Soc. 2003 Feb;62(1):25-9.