Differences Between Whole Grain and Refined Grain

Sack of flour with various grains surrounding it
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Nutritional guidelines say to choose whole grains rather than refined grains, but what is the difference between the two? As you might suspect, whole grains contain the original grain parts, as grown by the grain plant. Refined grains are processed—refined—to remove some of those parts.

Those original grain parts contain fiber plus other nutrients, and they're good for you, which is why health experts urge people to include whole grains in their diets. But whole grains and the flour produced from them don't make light, fluffy baked goods, which is why food product manufacturers might tend to avoid them for some products.

Parts of Grain Kernels

Grains include wheat, corn, rice, sorghum, barley, millet, rye, and oats. The seed of the grain plant, also called the kernel, is what is harvested. It contains three parts:

  • Bran: The fibrous shell covering the entire kernel
  • Endosperm: The starchy part of the grain directly below the bran
  • Germ: The part of the seed that can grow into another grain plant

The endosperm is the largest part of the kernel and the germ is the smallest. All parts of the kernel contain nutrients. The germ is the only part that contains healthy fats. The bran contains the bulk of the kernel's fiber.

Whole Grain vs. Refined Grain

Whole grain flour—from any type of grain, gluten-free or not—contains all three parts of the grain kernel, ground together. Refined grain flour contains only the endosperm—the process of refining flour removes the germ and the bran. Refining grain flour provides for a longer shelf life and a finer texture.

Whole grain flour has some real health advantages. It includes the fibrous bran and the nutrient-filled germ of the kernel. It also includes significantly more B vitamins, minerals, and fiber than does refined flour.

In fact, manufacturers add vitamins and minerals (specifically, folic acid and iron) back into refined wheat flour to make it a healthier food. However, there's no way to add fiber to refined flour without destroying its fine texture and potentially reducing its shelf life.

Gluten-Free Grain Flour: Mostly Refined

If you have celiac disease or non-celiac gluten sensitivity, you need to avoid the three gluten grains (wheat, barley, and rye) and possibly oats. The other grains are fine for you, as long as they haven't been cross-contaminated with gluten grains.

Although some gluten-free product manufacturers are using whole gluten-free grains to make healthier bread, the vast majority of gluten-free products on the market are made with refined gluten-free flour. For this reason, many people who follow the gluten-free diet don't get enough fiber, and some don't get enough B vitamins, either. You may need to boost several nutrients if you're eating gluten-free.

It's possible to find whole grain gluten-free flour. For example, King Arthur Flour makes a certified gluten-free flour blend. But most cup-for-cup gluten-free flours you'll see include refined grains, with white rice being the most common ingredient.

Also, when you're talking about gluten-free whole grains, you should know that some of what we think of as "grains" are really different types of plants entirely. Quinoa and buckwheat fall into this category, and both can make healthy whole grain substitutes.

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Article Sources
  • All About the Grains Group. United States Department of Agriculture ChooseMyPlate.gov.

  • Whole Grains and Fiber. American Heart Association.