Whole grains are composed of bran, germ and endosperm. When a grain is refined, such as in white bread or white rice, the bran and germ are removed, leaving only the endosperm. The beneficial vitamins, minerals, fiber and phytonutrients are contained within the bran and the germ, which is why whole grains are healthier than refined grains. Bran and germ products are also available separately, as in the case of wheat and oat bran, and are concentrated sources of many nutrients. While both oat and wheat bran are very healthy foods, they each offer distinct nutrient profiles.
Macronutrients
The fat, protein and carbohydrate composition of oat and wheat bran differ only slightly. According to NutritionData, oat bran contains one gram more of each macronutrient on a per-ounce basis. One ounce of wheat bran contains one gram of fat, 18 grams of carbohydrates and four grams of protein. One ounce of oat bran contains two grams of fat, 19 grams of carbohydrates and five grams of protein.
Vitamins
Wheat bran and oat bran are both good sources of vitamins, particularly B vitamins. According to NutritionData's nutrient analysis, wheat bran contains 10 percent or more of the daily value of four B vitamins---thiamin, riboflavin, niacin and vitamin B6. Oat bran, on the other hand, only contains that much of one vitamin, thiamin. The amount of thiamin in oat bran is actually three times greater than in wheat bran.
Minerals
Oat bran and wheat bran are also good sources of multiple essential minerals. Both are great sources of magnesium, phosphorus, manganese and selenium. In fact, one ounce of wheat bran contains 3.2 milligrams of manganese, which is 161 percent of the daily value. They also are both good sources of potassium, zinc, iron and copper. Wheat bran contains more of all these minerals than does oat bran, when compared on an ounce-for-ounce basis, according to NutritionData.
Fiber
Both oat and wheat bran are good sources of fiber, though the type of fiber they contain differs. One ounce of wheat bran contains 12 grams of fiber, while one ounce of oat bran contains four grams. According to the American Heart Association, oat bran is a good source of soluble fiber, while wheat bran is a good source of insoluble fiber. Both types of fiber are important for health. Soluble fiber may help to decrease cholesterol levels, and insoluble fiber promotes healthy bowel functioning.
Cancer Prevention
According to WHFoods, wheat bran has been show to have specific cancer-preventing properties that oat bran cannot match. Wheat bran may promote increases in the metabolism of estrogen in the body, which may help decrease the risk of developing breast cancer. Wheat bran has also been shown to decrease the amount of cancer-promoting substances in the colon, making it a potential protector against colon cancer as well.
