by Sue Becker
Much is being said today about adding “fiber” to the diet. Articles on improving health and eating habits are appearing in all types of publications stressing the importance of fiber. Despite its publicity, most of us, however, don’t understand what fiber really is, what its food sources are, nor the significant role it plays in our body’s system.
Technically, fiber is a group of non-digestible carbohydrates. Since we don’t digest fiber, it is passed through the stomach and small intestines, and dumped as waste into the colon (large intestine). The bacteria of the colon begin to feed on some of this undigested fiber producing as by-products many of the B vitamins and vitamin K. The rest of the undigested fiber is actually excreted. Despite its transit through the body, this undigested fiber performs many vital health functions along the way, depending on the type of fiber it is.
SOLUBLE OR INSOLUBLE
Nutrition experts classify fiber as either soluble or insoluble in water. Insoluble fiber, commonly known as roughage, acts as a cleansing agent in the digestive system. It is this coarse fiber that is the outer, protective layer of seeds, known as bran. Insoluble fiber also gives plants and vegetables their firmness.
Once food is digested in the stomach and the nutrients are absorbed through the walls of the small intestine, the “waste” with the undigested fiber is passed into the colon. The colon’s function, then, is to create a solid material to be eliminated by the bowels. The insoluble fiber acts much like a sponge in this process, absorbing water drawn into the colon and thereby increasing the bulk, while softening the stool. The increased bulk of the stool applies pressure to the walls of the colon, stimulating gentle, rhythmic contractions of the colon, known as peristalsis, which then in turn produces the urge to eliminate. The roughage of insoluble fiber, such as the bran portion of grain, is also mildly abrasive and serves to gently scrub the walls of the colon clean during elimination.
Since bulkier stools fill the colon more quickly and the urge to eliminate comes only when the colon is full and pressure exerted, insoluble fiber “shortens the transit time”, meaning we will eliminate more frequently and regularly. Do not, however, mistake these more regular, bulky movements with the frequent, yet very loose watery bowel movements of some people. This chronic, diarrhea type of elimination is caused by the abnormal peristalsis contractions of the colon trying to eliminate old built up waste not completely removed before. The watery, loose stool is due to the lack of fiber in the colon to absorb the excess water drawn in by the increased contractions. In actuality, these symptoms are nothing more than advanced complications of constipation.
One should now see that the true cause of constipation, which so readily plagues our nation, is food that is so very completely digested (i.e. lacking fiber) that it leaves no residue, such as fiber, to hold water. To the extent that the fiber can hold or absorb water affects its ability to produce bulk and function as a cleaning agent.
SOURCES OF FIBER
The most effective and abundant source of insoluble fiber comes from the bran portion of whole grains. Insoluble fiber is also found in beans, vegetable skins, and firm fruits and vegetable such as broccoli, carrots and apples. No significant fiber of any kind is in lettuce.
Another important aspect of insoluble fiber is that it readily absorbs toxins in the digestive tract. Many researches believe that by speeding the elimination of toxins from the intestinal tract, insoluble fibers lower the risk of developing colon cancer.
Soluble fiber, on the other hand, is the non-structural compound of plants, such as gums and pectin, which gelatinizes as it dissolves in water. In the digestive tract, soluble fiber binds with critical compounds and speeds their elimination from the body.
Pectin for instance, binds with fats and speeds its excretion from the body. Apples, bananas, cabbage, citrus fruits dried peas, and okra are good sources of pectin. Gums, found in oats and beans, are helpful in reducing cholesterol by binding with bile acids (a cholesterol raw material) and carrying them through the intestines to be eliminated.
Soluble fiber also appears to help regulate blood sugar levels by delaying sugar absorption in the lower intestinal tract, thereby keeping levels more constant. This reduction in the numerous rapid rises and falls of blood sugar levels helps to prevent such complications as hypoglycemia and diabetes.
FIBER AT EVERY MEAL
Breakfast provides an optimum opportunity to indulge in fiber. Freshly rolled oatmeal, freshly ground grits, barley pudding (recipe included this issue), or muffins, coffeecake, or pancakes made with freshly ground flour all can be served to compliment your family’s favorite breakfast foods.
For lunch, a sandwich on bread made from freshly milled whole grain increases you insoluble fiber intake. Add a piece of fresh fruit or raw carrots to supply the soluble fiber. (We’ve discovered baby carrots. They are kid friendly in that they are ready to eat (no scrubbing) and travel well.)
At dinner, dishes with brown rice (rice with the bran intact), whole grain pasta, or peas and beans and always some type of bread or roll supplies a variety of fibers. Beans provide a particularly high dose of fiber plus are a wonderful source of protein. Side dishes of fruits and vegetables not only compliment your favorite main dish but also increase your fiber intake even more. High fiber vegetables include broccoli, brussel sprouts, baked potato (with skin), sweet potato, and spinach. Apples, pears, plums, and bananas are just few of the high fiber fruits.
Increasing your fiber intake without increasing water consumption may cause constipation and bloating. As explained earlier, fiber absorbs water in the digestive tract, therefor you must drink extra water. It is important to drink water-other fluids won’t bring the same results. I begin each day with a large glass (16 oz.) of water before I eat anything. It is very stimulating to both the colon and the salivary glands in your mouth. I call it priming the pump!
Do not be fooled by store bought “wheat” breads, dark in color that appear to be whole grain. Read the label! It is very difficult, however, if not impossible to buy commercially prepared bread or flour that is not stripped of its fiber and therefor will not give the same beneficial effects as bread made from grains you have milled yourself. Even flour labeled “whole wheat” has had some of the bran and nearly all of the oil-containing germ removed to prevent spoilage.
Many experts recommend consuming at least 20-35 grams of fiber per day. Unfortunately, the average American consumes only about 12 grams per day. If you change your breads to those made with fresh ground grains and make grains a part of every meal, then consciously increase your fruits and vegetables, you will find it easy to eat the required amount of fiber without worrying about counting every gram.
As you can see, a few simple dietary changes can make getting the benefits of high fiber and whole grains easy and doable. Changes such as these increases not only your fiber intake, but also adds many other essential nutrients greatly lacking in the American diet today.
The Physiology Coloring Book, by Kapit, Macey and Meisami; Harper Collins
DISCLAIMER: Nothing in this article should be construed as medical advice. Consult you health care provider for your individual nutritional and medical needs. The opinions are strictly those of the author and are not necessarily those of any professional group or other individual.