Whole wheat and wheat bran with a lot of insoluble fiber are great bowel activators. Wheat bran seems able to suppress colon polyps that tend to develop into cancer, while in women it reduces estrogens and helps prevent breast cancer. But even the soluble fiber of wheat has beneficial effects for our cardiovascular system.
Caution: Wheat is one of two of the greatest causes of allergies and food intolerances in the world. The other is milk.