Fiber is necessary for a healthy bowel as it is an important substance for elimination of toxic and byproduct as they bind to the fiber. It also controls the rate at which elimination takes place, as it is stimulating bowel movement. Fiber is made up of different combinations of cellulose, hemicelluloses, pectin, beta-glucan, chitin, gums, lignin and resistant starches.
The dietary fibers are either soluble or insoluble, and they are both promoting a healthy bowel. Soluble fibers are slowing down the digestion while insoluble fibers are making the food pass quicker through the body. Both soluble and insoluble fiber absorbs water, but only the soluble creates a gel-like substance that is promoting a healthy bowel. The gel is the reason digestion slows down as it prolongs the digestion. It is therefore used to stabilize the blood sugar as absorption of carbohydrates is prolonged.
One reason fibers from vegetables are more preferred then the fibers from breakfast cereals is because it is more natural in the vegetables. The breakfast cereals have most of the time been exposed to both heat and pressure during production/formation. In the making of cereals a lot of chemicals (unnatural process) might have been used and chemical agents can be added to make it look, smell, taste or feel a specific way. Crazy, I know! It is also normal that the fibers are added after the substances have been treated with all different sorts of techniques, products that from the beginning contained fiber, minerals and vitamins. Now long gone! The added fibers are not as natural as it was from the beginning and as natural as in vegetables and fruits.
If the companies are using the whole grain and are not removing the outer cover/bran, there is a risk that mineral deficiency develops. This because there is a substance called phytic acid in the outer cover, that are preventing absorption of minerals by getting attached to mineral such as zinc, calcium, magnesium and iron. We know that fibers are not absorbed and if the minerals bind to the fiber, they won’t be absorbed either. Most fibers are located in the outer layer of a grain and not much inside the layer/covering/membrane. But as we are comparing fibers from “green” kingdom and cereals with bran, we know that the cereal product contain fiber (as most of the fiber are in the bran) and also that mineral deficiency can develop if too high amount are taken.
Most vegetables contain soluble fiber and are therefore lengthening the digestion time and controlling bowel movement. But it is not possible to draw a line and say “Grains are insoluble and vegetables are not”, as they contain both. It depends on the build-up of that particular fiber. As mention at the beginning, fibers are build up of different combinations of cellulose (insoluble), hemicelluloses (insoluble and soluble), pectin (soluble), beta-glucan (insoluble and soluble) , chitin, gums, lignin (insoluble) and resistant starches, and all of these building blocks react differently. As fruit and vegetables contain soluble fiber it is also good for detoxification and elimination of byproducts, one example is bile that can bind to the fiber and therefore be eliminated from the body. Grains are most of the time insoluble, but exceptions exist.
The vegetables and fruits are also rich in minerals and vitamins that are important for detoxification (from within) as it can support the liver (the main cleaning station of the test tube). Potassium, sulfur (union and Brussels sprouts), chlorine (celery) are some that are helping detoxification. But this brings up another important difference of fiber from vegetables & fruit, and grains. Fruits and vegetables contain much more mineral and vitamins then grains do, and this is an important part as well. Grains mainly give energy in the form of carbohydrates, instead of giving nutrients.
If we are cooking the vegetables slightly before eating we are softening the cellulose, which makes it easier to get hold of the nutrients buried in the vegetable. This is one of the reasons we are recommended to eat both cooked and uncooked vegetables.
Another problem with cereal is the amount of gluten it may contain, if gluten free grains have not been used. The gluten can be harmful if the person are sensitive or allergic, which is more a norm/rule than an exception it this community.
Good sources of fiber include a number of grains used in breakfast cereals: barley, oats, corn, millet, wheat, wild rice, brown rice, kashi and bulgur are some grains commonly found in breakfast cereals and porridges.