Wheat: the Whole (Grain) Story

Gerald F. Combs, Jr.

We live in a virtual sea of wheat.  North Dakota leads the nation in growing it.  Around the world wheat is grown on more land area than any other crop.  It has been cultivated for some 8000 years, and its availability as a staple is thought to have been a major contributor to the development of civilizations in Europe and parts of Asia and Africa.  Indeed, wheat is an important food grain in our diets. 

Of course, we don't eat wheat in the form it comes from the field.  We make the grain into a seemingly endless variety of breads, cakes and pastas.  We eat it in the morning hot from the griddle or flaked and covered with milk or yogurt, as snacks at work breaks, for lunch as tortillas or sandwiches spread with meat or cheese or peanut butter, for dinner as pizza or pasta dressed with tomato sauce or cheese and vegetables, and sweetened for desert.  We eat wheat foods to celebrate birthdays and weddings, when we have guests and also just to feel good.

To make these many foods, the whole wheat kernel must be broken into tiny particles that can be readily hydrated to release the proteins and carbohydrates that give cohesion to the final products.  This process of milling goes back as far as wheat cultivation itself.  Originally, it involved pounding the dry kernels with a wooden hammer; this evolved into the use of mill stones that were turned by the power of humans or animals or falling water.

It was the availability of water power that attracted in the 1850's New England millers, the Washburns and Pillsburys, to what is now Minneapolis where they established water-powered flour mills at St. Anthony Falls on the Mississippi River.  There, mills had ready access to the superior bread wheat abundant in the upper Midwest.  However, the millers found it difficult to separate the dark bran particles from the wheat kernel's white, starchy center; so their stone-milled product had grayish color.  The problem was solved by installing European steel roller mills and other machinery to grind finely and sift out the dark bran components.  With a location that allowed shipping by rail to the east and down river to New Orleans and abroad, Minneapolis became the milling capital of the world for the latter half of the nineteenth century.   All of this was made possible by the ability to produce a pure, fluffy, white flour of unmatched quality.

White flour is white largely because other parts of the grain, the darker bran and the germ, have been removed.  That makes it easier to chew, easier to digest and easier to keep without refrigeration.  Removal of those parts leaves the kernel's starchy center, the endosperm, and yields a fluffy, white flour that makes light and airy breads and pastries. 

Most white flours represent only 72 percent of the original whole grain.  The milling away of those other portions of the grain results in the removal of valuable nutrients that the wheat plant puts into the bran and germ.  Those nutrients include iron, several vitamins and fiber.  For this reason, the U.S. Food and Drug Administration permits refined flour to be "enriched" with several nutrients that are lost in milling (iron, and the vitamins thiamin, niacin and riboflavin) and mandates that most enriched wheat flours, breads, noodles and macaroni also be fortified with the vitamin folic acid. 

Whole wheat flour is made by milling 100 percent of the kernel into a powder.  Very similar whole grain products are made by recombining the separated milling fractions in the proportions originally present in the whole kernel.  These are similar in appearance.  Both are good sources of dietary fiber.

The Dietary Guidelines for Americans suggest a daily intake of 2-3 servings of grain-based foods, or about half of the present national average.  They specifically call for half of that intake being whole grain products, and for limiting daily intake of refined grain products, particularly those high in solid fats and/or added sugars such as cakes, cookies, donuts and other desserts.

Whole grain flours can be used in most cases instead of refined flours.  Whole wheat breads are made with whole grain flour comprising at least a portion of the dough.   Studies in the Minneapolis public schools found that groups of bona fide pizza experts - middle schoolers - eagerly accepted pizzas made with dough made from as much as 70 percent whole grain wheat flour.  The development of white wheat varieties has allowed bakers to produce whole grain products that are virtually indistinguishable from breads made using refined, white flour.

It pays to choose whole grain foods.  They give you what your grandma might have called "roughage" but what health professionals call dietary fiber.  Americans consume about half the recommended amounts of dietary fiber (25 grams for women, 38 grams for men).  Studies show that that consumption of 2-3 daily servings of whole grain products was associated with 20-30 percent reductions in risks to cardiovascular disease and type 2 diabetes, and also to reduce risks to colorectal cancer or inflammation-related conditions. 

More information about the Dietary Guidelines can be found at:  www.health.gov/dietaryguidelines/2010.