Differences Between Whole Grains and Refined Grains


Verywell / Alexandra Shytsman

Nutritional guidelines say to choose whole grains rather than refined grains, but what exactly is the difference between the two? Whole grains contain most of the original grain intact, as grown by the grain plant. Refined grains are processed—refined—to remove some of the outer casing or inner seed.

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.

What Exactly Is a Grain?

Grains include wheat, corn, rice, sorghum, barley, millet, rye, oats, and others. 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
  • Contains all three parts of the grain kernel

  • Slightly denser texture

  • Higher in fiber and B vitamins

  • Shorter shelf life

Refined Flour
  • Contains only the endosperm

  • Finer texture

  • Lower in fiber and B vitamins, but often higher in folate

  • Longer shelf life

Many manufacturers add in vitamins and minerals (specifically, folic acid and iron) that were lost due to processing 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.

What About Gluten-Free Grains?

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

Refined-Grain Gluten-Free Flour

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 look for other sources of these nutrients if you avoid gluten.

Whole-Grain Gluten-Free Flour

It is 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 (technically a seed) and buckwheat (actually a grass) fall into this category, and both can make healthy whole-grain substitutes.

5 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. U.S. Department of Agriculture. What foods are in the grains group?.

  2. Khalua RK, Tewari A, Mondal R. Nutritional comparison between brown rice and white rice. Pharma Innovation. 2019;8(6):997-998.

  3. American Heart Association. Whole grains, refined grains, and dietary fiber.

  4. Lindfors K, Ciacci C, Kurppa K, et al. Coeliac disease. Nat Rev Dis Primers. 2019;5(1):3. doi:10.1038/s41572-018-0054-z.

  5. Vici G, Belli L, Biondi M, Polzonetti V. Gluten free diet and nutrient deficiencies: A reviewClin Nutr. 2016;35(6):1236-1241. doi:10.1016/j.clnu.2016.05.002.

By Nancy Lapid
Nancy Ehrlich Lapid is an expert on celiac disease and serves as the Editor-in-Charge at Reuters Health.