The Importance of Dietary Fiber
If You Want To Be Healthy, You've Got To Eat Healthy

What is dietary fiber?
Food is fuel. When you eat, your digestive system uses enzymes to break down nutrients like proteins, carbohydrates and vitamins so they can be used by your body. These nutrients become energy and the physical building blocks of the body.

Some parts of the food we eat are indigestible and can't be broken down by the human body. Called dietary fiber, these indigestible portions are non-nutritive, supply zero calories and are found only in plant foods. However, they play a critical role in keeping the digestive system running smoothly, and in the prevention of many diseases.

The five different kinds if dietary fiber can be divided into two classes. Insoluble fibers, of those that won't dissolve in water, include cellulose, lignin and hemicellulose (though hemicellulose is somewhat soluble). When eaten, these dietary fibers absorb water, adding bulk to waste and speeding its journey through the intestines.

Pectin (like that used to make jam), along with sticky plant secretion called gums, make the water soluble fiber category. They bind with other food substances, delay absorption of carbohydrates and help keep cholesterol levels in check. Current research with oat bran and psyllium husk, which have soluble fiber, shows this effect.

Why is it important?
Fiber intake in North America is only one-fifth what it was a hundred years ago. The backlash of our so-called modern diet is now being seen. Current research shows that many serious diseases common in North America are virtually non-existent in places like rural Africa where high fiber intake is routine.

For example, diverticular diseases is unheard of among populations that eat high-fiber diets. In North America, diverticular diseases affects about one in 10 persons over 40 and about half the population over age 65.

Colon cancer is one of the greatest cancer killers of non-smokers. Research indicates high fat diets promote the development of this disease while high dietary fiber intake inhibits it.

Some dietary fiber is actually broken down by bacteria living in the digestive tract. Researcher believe these healthy bacteria bind cancer causing agents and render them harmless. It is thought a diet high in fiber encourages the proliferation of these anti-cancer bacteria which in turn reduces the risk of cancer. Other researchers believe that fiber's bulk dilutes cancer causing substances and sweeps them from the digestive tract, giving them less time to do their deadly work.

It's fact that people who eat high fiber diets, like vegetarians, have lower blood pressure and less heart disease then the general population. Diets high in soluble fibers (pectins and gums) lower the "bad" (low density) cholesterol - a major cause of heart disease - and raise the level of "good" cholesterol and related substances, dietary fiber reduces the risk of heart disease and other cardiovascular disease.

Increased fiber intake may also be beneficial in the treatment of certain kinds of diabetes.

After you eat, the breakdown of carbohydrate boosts your blood glucose (sugar) level. In people with a normal capacity to produce insulin this sugar "peak" drops in about an hour. In insulin deficient diabetics, the peak can stay dangerously high for longer periods. By accelerating food through the digestive system and slowing down carbohydrate absorption, dietary fiber reduces the need for the insulin surge usually needed to keep blood sugar levels. (Warning diabetics should consult a doctor before any diet change.)

A high fiber diet benefits the blood sugar level of those without diabetes, too. Certain fibers help regulate blood sugar by controlling the rate and site of nutrient absorption. This helps you have sustained energy over a longer period of time, rather than a blood sugar rush followed by lack of energy.

Recent medical evidence has illustrated that people with high fiber diets show a reduced risk of various types of cancer including colon cancer, breast cancer, and prostate cancer.

Half the population of North America takes laxatives. Although laxatives can help constipation and hemorrhoids, they can cause serious side effects especially if you become dependent on them. Dietary fiber is a safe, natural laxative that can be taken long-term without danger.

High-fiber diets tend to be lower in calories than other diets. Dietary fiber also absorbs water and takes up more room in the stomach. You feel fuller longer because fiber slows down your digestion.

How much fiber do I need?
Most North Americans eat about 8 to 11 grams of fiber per day. That's less than half the recommend daily amount of 20 to 35 grams. It's also less than 20 percent of the dietary fiber intake of many individuals in developing countries.

You probably need to increase your fiber intake, but be careful and do it slowly. The signals to watch for are the frequency, comfort and bulk of bowl movements.

But start slowly. Gas, bloating, abdominal pain and diarrhea can result from too much fiber too fast. Over consumption of fiber can work against you by blocking the absorption of many valuable nutrients.

Pregnant or nursing women and people who are chronically sick, undernourished, over the age 65 should consult with a physician before making any radical change in diet.

Which foods are high in fiber?
Dietary fiber is found only in plant foods - fruits, nuts, grains, and vegetables. It doesn't exist in meat, fish, and dairy products. Eating a balanced diet requires you eat a variety of foods. And eating a balanced diet means you must eat foods containing both soluble and insoluble fiber.

The highest foods are whole grains cereals, followed by legumes, root vegetables and then fruits. Different fibers initiate different physiological responses, so you need to eat from all these fiber rich food groups to get the various types of fiber your body needs. With a diet rich in several types of fiber you can eat your way to better health!

Some hints

• When you eat fiber you must also increase your fluid intake. Drink at least eight glasses of water each day.
• Don't be fooled by appearance. Some foods that appear fibrous, such as lettuce and celery, actually have little dietary fiber. In the other hand, soluble fibers may not appear fibrous - a potato baked in its skin is high in dietary fiber.
• Over processed and refined food contain less fiber than food in its natural state. When cooking with apples, leave the skin on, substitute an orange for orange juice in the morning and use brown rice instead of white. Use whole grain cereal products for snacks along with raw fruits and vegetables.
• Exercise regularly.

Advantages of a high fiber diet
Reduces the risk of heart disease - Lowers blood pressure - Lowers serum cholesterol - Reduces the risk of certain cancers - Helps prevent digestive diseases - Regulates blood sugar - Aids digestion - Promotes regularity - Contributes to bowel cleansing.

Sources: Dietary fibre, published by British Columbia Medical Association; Nutrition Recommendation (1990), published by Health and Welfare Canada.

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