A whole grain is comprised of three layers. In the center lies the starchy white, nutritionally-void endosperm. This is surrounded by the germ; which is rich in B vitamins, vitamin E and protein. The outer shell is the bran, containing many vitamins, minerals and proteins. This also contains most of the dietary fiber that helps move toxins and other substances through and out of your digestive tract.
Unfortunately, many products on supermarket shelves today are highly processed to remove the bran and germ from the grain to give them a higher shelf life. Some products are then "enriched" with things like thiamin, riboflavin, niacin, iron, folic acid and maybe calcium, but these are replaced in unnatural proportions leaving products significantly less nutritious compared to unprocessed whole grain products.
Products like white bread, pasta and other bakery goods are often made with processed flour. So, if you want to ensure you are consuming enough dietary fiber, consider adding bran sources to your diet.
Oat bran, the outer layer of the oat grain, is a good source of soluble fiber. It can help absorb cholesterol; which may help ward off heat disease and control diabetes.
Wheat bran, the outer layer of the wheat grain, is a good source of insoluble fiber. It's a good stool binder and softener; which can help relieve constipation and other digestive disorders.
Rice bran oil, extracted from the outer layer of the rice grain, is rich in vitamins, antioxidants and other nutrients that can help lower cholesterol, enhance immunity and fight damaging free radicals. It's a light, versatile cooking oil that's free of trans fats.