Functional Foods – Grains

Another food group composed of functional foods is whole, intact grains that are high in potassium. Many whole grains are high potassium foods and thus contribute to lower blood pressure, less osteoporosis and fewer kidney stones. Many of the beneficial qualities of whole grains are because of their high potassium content. But there are other aspects of the whole grains that also contribute to health. These aspects can slow insulin secretion, reduce unfavorable LDL cholesterol and reduce inflammation throughout the body.

Differences Between Intact And Refined Grain

What are the differences between intact grains and refined grains that contribute to these effects? Whole grains include more nutrients, have less sodium and if the grains are intact (not simply the ground up whole grain) they are more slowly digested. They contribute to lower mortality.

Many of the processes involved in refining grains destroy nutrients in the grain. Heating destroys the heat labile nutrients. Chemicals added to preserve or change texture have other effects beyond the preservation or texture change. By adding sodium for longer shelf life, the favorable potassium to sodium ratio of intact grains is destroyed.

Functional Metabolic Effects

By grinding the grain into a fine powder, the carbohydrates in the food are more quickly absorbed than in the intact grain. Thus, blood sugar rises more quickly and insulin spikes, leading to a rapid fall in blood sugar and a tired feeling. When blood sugar rises and falls quickly, hunger returns within 2 hours and people eat more often leading to more calories absorbed in a day and thus more obesity and insulin sensitivity (1).

By including the whole grain, the insoluble and soluble fiber are retained. The soluble fiber contributes to lower LDL cholesterol and thus lower amounts of plaque buildup in the blood vessels and heart vessels. The insoluble fiber speeds passage of food through the intestines, giving less time for harmful waste products to buildup in the intestines. The fiber from intact grain, but not refined grain is associated with reduced mortality (2).

Several studies have shown lower amounts of inflammatory markers in the body after meals composed of whole grains (3). This may be related to the slower rise in blood glucose, since there is a higher amount of reactive oxygen generation with a high blood glucose level. Another possible explanation is the phytochemicals present that may be able to blunt the free radicals.

Tables Of High Potassium Foods

A table of high potassium grains with macronutrient, fiber, potassium and sodium content can be found here. For a list containing tables of other food groups, click here.
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1. N. M. McKeown, J. B. Meigs, S. Liu, P. W. F. Wilson, and P. F. Jacques, “Whole-grain intake is favorably associated with metabolic risk factors for type 2 diabetes and cardiovascular disease in the Framingham Offspring Study,” American Journal of Clinical Nutrition, vol. 76, no. 2, pp. 390–398, 2002.
http://ajcn.nutrition.org/content/76/2/390.long

2. D. R. Jacobs, M. A. Pereira, K. A. Meyer, and L. H. Kushi, “Fiber from whole grains, but not refined grains, is inversely associated with all-cause mortality in older women: the Iowa Women’s Health Study,” Journal of the American College of Nutrition, vol. 19, no. 3, pp. 326S–330S, 2000.
http://www.jacn.org/content/19/suppl_3/326S.long

3. P. L. Lutsey, D. R. Jacobs, S. Kori et al., “Whole grain intake and its cross-sectional association with obesity, insulin resistance, inflammation, diabetes and subclinical CVD: the MESA Study,” British Journal of Nutrition, vol. 98, no. 2, pp. 397–405, 2007.
https://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=1208272