Health Enhancement Services

Why should I eat more fiber? Can you eat too much fiber? What is the best source of fiber? How important is it to my health? This column should answer these questions and give you information about fiber and ways to increase your fiber intake.

Fiber is not a single substance. Fiber is contained in plants and is that part of the plant material that, when eaten, does not get digested. It is an enormous group of widely different substances which, for simplicity, can be divided into two basic groups.

Type I fiber comes from wheat bran and whole-grain breads and cereals. This fiber acts as a sponge, absorbing water. It also speeds passage of wastes, aids elimination and cleanses the bowel. Type II fiber comes from fruits, vegetables, nuts, brown rice, barley and oats. This fiber reduces serum cholesterol and the entry of glucose into the bloodsteam.

In the early 1970s, researchers first linked the high-fiber diets of rural Africans with a low incidence of the diseases all too common in industrialized Western countries. While not all of the findings have been confirmed, a number of subsequent studies have indicated that various types of fiber may help to prevent or improve the following conditions and diseases.

Constipation: whole-grain fiber inevitably halts common constipation when taken with adequate amounts of fluid.

Cancer: Colon cancer is rare among people with a diet low in meat and rich in high fiber foods. It is the second most common form of cancer in the United States.

Heart disease: It is known that elevated cholesterol levels are one of the chief risk factors in heart disease. Type II fiber has the effect of lowering the LDL (bad cholesterol) without decreasing the HDL (good cholesterol).

Diabetes: Elevated blood sugar levels are a major problem in diabetes. Some researchers have shown that the gums in Type II fibers may reduce blood sugar levels. This effect has only worked with adult-onset diabetes, not juvenile diabetes.

Obesity: People who eat high fiber diets are seldom obese because fiber is filling without adding calories. Fibrous foods also take longer to chew, which slows eating time. But fiber itself does not lower the number of calories absorbed.

The National Cancer Institute recommends eating foods that provide 25 to 35 grams of fiber daily. While it is beyond the limitations of this column to provide a comprehensive list of fiber sourcs, some good sources of fiber include: peas (1/2 c. = 6.7 gms), peanuts (3 oz. = 8 gms), All Bran cereal (1/2 c. = 12.6 gms), lima beans (1/2 c. = 8.3 gms), raspberries (1/2 c. = 4.6 gms), bran muffin (one med. = 4.2 gms), baked potato (one med. = 3.9 gms), broccoli (1/2 c. = 3.8 gms), banana (one med. = 3 gms), wholewheat bread (one slice = 1.3 gms) and celery (one stalk = 1.1 gms).

You can ensure an adequate fiber intake by adopting these steps:

1. Eat a variety of foods; the less processed, the better.

2. Eat more fruits and vegetables, as many raw as possible. Fiber is more useful raw than when peeled, cooked or processed. Potato skins are high in fiber.

3. Drink plenty of liquids (especially water and juices), otherwise fiber can slow down or even block digestion.

4. Spread out your fiber intake. Try to have some of each type of fiber at each meal. Getting it all in one sitting may cut the benefits and increase the chance of unpleasant side effects.

It is difficult for the average person to get too much fiber. But taking too much too soon can cause intestinal gas due to fermentation in the colon. This isn’t serious and subsides once the bacteria in your system adjusts to the fiber increase. Another potential adverse effect is the tendency of fiber to bind trace minerals, such as zinc and iron, and to lessen their absorption. This should only be a problem for someone whose diet is nutritionally poor. For more information on fiber visit the Wellness Resource Center in the Holmes Student Center, or call 753-1435.