The grain group provides many important nutrients, such as thiamin, riboflavin, niacin, dietary fiber, magnesium, and iron.  When a whole grain goes through a refining process, the germ and bran layer is removed and many of the nutrients are lost. An enriched grain has four vitamins (thiamin, riboflavin, niacin, and folic acid) and one mineral (iron) added back in. However, several of the lost nutrients such as fiber, magnesium, and zinc) are not replaced.  Many refined grain products, such as commercial muffins and cookies, have additional refined added sugars, and unhealthy fats added that decreased their nutrient density. Excessive consumption of these types of products is associated with increased risk of disease such as obesity, diabetes, and cardiovascular.

A large meta-analysis published in the British Medical Journal in 2016 reported the consumption of whole grains was associated with a reduction in cardiovascular disease, respiratory disease, infectious disease, diabetes, and mortality from all causes.1 Both the American Heart Association and the American Cancer Society support the consumption of whole grains for disease prevention.