The High Fiber Diet

Dietary fiber is the part of a plant that cannot be digested by the body. Just as there are many types of plants, there are also many types of fiber. Some fibers, such as bran, are soluble in water and form a gelatinous bulk that can lower cholesterol. Other fibers, such as wheat bran, are insoluble and add bulk to the stool. Both are important and provide benefits.

The Function of the Large Intestine

The principal function of the large intestine (colon) is to remove excess water from food wastes passing into it from the small intestine. When food passes through the large intestine too quickly, not enough water is absorbed by the intestine, and diarrhea results. In contrast, if waste material is passed too slowly, too much water is absorbed. This results in hard stools and constipation, often leading to straining.

The Importance of Dietary Fiber

Fiber, also called roughage or bulk, is necessary to promote the wavelike contractions that move food through the intestine. High fiber foods expand the inside walls of the colon, easing the passage of waste. As fiber passes through the intestine undigested, it absorbs large amounts of water, resulting in softer and bulkier stools.

Rural Africans digest and eliminate the foods they eat in one-third the time it takes people who live in Western cultures. The rural African diet is rich in fiber. This speeds up the time required to digest food and expel wastes. It is believed that this helps sweep out harmful substances before they can cause problems in the body. In fact, these rural peoples suffer less from many of the digestive tract diseases that plague Western man, and it is thought that this may be related to the nature of their diet.

A high-fiber diet causes a large, soft, bulky stool that passes through the bowel more easily and quickly. This helps to prevent, stop or even reverse some digestive tract disorders. A softer, larger stool helps prevent constipation and straining, which can help avoid or relieve hemorrhoids. More bulk means less pressure in the colon, and this is important in treating irritable bowel syndrome and diverticulosis.

Most Americans eat only 10 to 15 grams of fiber a day. The recommended intake is 20 to 35 grams a day. High fiber foods, such as fruits and vegetables, also tend to be low in calories, so they should not cause weight gain. Fiber pills generally should be avoided. They contain relatively little fiber and are expensive. Fiber containing food and powdered fiber supplements are better sources.

Fiber and Irritable Bowel Syndrome

Irritable Bowel Syndrome, sometimes called IBS, is one of the most common disorders of the lower digestive tract. There is no disease present in IBS. However, its symptoms can resemble other disorders. The symptoms of IBS are constipation, diarrhea (or both alternately), abdominal pain, cramping and spasms. Acute episodes can be triggered by emotional tension and anxiety, poor dietary habits and certain medications. Increased amounts of fiber in the diet can help relieve symptoms of IBS by producing soft, bulky stools and by helping to normalize the time the stool takes to pass through the colon. The increased bulk also reduces the pressure necessary to push food waste through the colon. This results in less discomfort. If IBS is not treated it may lead to diverticulosis of the colon.

Fiber and Diverticulosis

Colon diverticulosis occurs when pockets or sacks bulge out from the bowel wall. It is known that these diverticula occur gradually over time and are due to excessive pressure or spasms within the bowel. These pockets usually cause no problem, but sometimes they can become infected (diverticulitis) or even break open, causing abscess or peritonitis. A high-fiber diet may act to increase the bulk in the stool, which reduces the pressure within the colon. By doing so, diverticula formation may be reduced or even stopped.

Fiber and Cholesterol

As noted above, fiber generally is divided into two categories. Insoluble fiber is found in wheat bran and in celluloses from vegetables and fruits. Soluble fiber is commonly found in oatmeal, oat bran (the best source), guar gum, psyllium seed, fruit pectin and gum Arabic. When mixed with water, it produces a gelatinous mucous gel. It, too, has bowel-regulating effects. It also acts to lower blood cholesterol by binding with cholesterol in the intestine and carrying it away in the stool. So, a high fiber diet should contain both types of fiber.

Fiber and Cancer

Recent evidence seems to indicate that fiber, by itself, even up to 25 grams a day, does not reduce the risk of colon or other cancers. However, many high fiber foods are also very rich in chemicals called antioxidants. These substances attack other chemicals known as free radicals. Free radicals occur in the body as a natural byproduct of metabolism. Yet, they can damage surrounding cells and seem to be related to increased risk of heart disease, macular degeneration (eye problems), and some cancers such as prostate cancer. Hundreds of very potent antioxidants occur in many fruits and vegetables that are also high in fiber. Nature seems to have naturally put these two substances together. Five portions of fruit and/or vegetables are recommended each day. Select those that are rich in color such as dark green, yellow, red or orange.

Fiber and Whatever

What else may high fiber help? In many instances the medical evidence is soft or fragmentary. Yet the preponderance of evidence is so overwhelming that high fiber foods can be recommended for just about everyone. Other diseases that are or may be benefited by high fiber foods are:

• Diabetes
• Bowel Irregularity
• Constipation or Diarrhea
• Macular Degeneration
• Hiatal Hernia

High Fiber Foods

High Fiber foods can be found in most food groups. Different types of food should be selected to get the benefits of them all.

• Legumes: including kidney, pinto, navy, lima and baked beans. The bean family excels in fibers, especially the soluble, cholesterol-lowering type;
• Whole Grains: Wheat bran and oat bran are present in a variety of cereals and breads. The label should say that the bread contains whole wheat or whole grain. Plain wheat bread may lack the fiber. One cannot always tell by the color. Some manufacturers artificially color bread brown to make it look more wholesome;
• Whole Fresh Fruits: The valuable pectin fiber is found in the skin and pulp. Figs, prunes and raspberries have the highest fiber content;
• Cooked or Stewed Fruits: Prunes and applesauce are good choices.
• Green Leafy Vegetables: Lettuce, spinach, celery and broccoli are good examples;
• Root Vegetables: Potatoes, turnips and carrots are all excellent sources.

Since bran can cause rumbling intestinal gas and even some mild cramping, it should be started in small amounts initially. The amount can be increased as tolerance is acquired. The goal should be 20 to 35 grams of fiber a day, which will usually produce 1 to 2 soft, formed stools a day.

The following are good general rules:

• Drink plenty of liquids, including fruit or vegetable juices and water.
• Eat slowly and chew food thoroughly to allow the upper digestive tract (esophagus, stomach and small intestine) to work well. This may prevent problems from developing in the lower digestive tract.
• Eat meals at regular intervals.

A Dietary Fiber Supplement May Be Helpful

Some people have trouble tolerating too many high fiber foods in the diet. Stool softening and bulking agents are available over the counter. These products are usually plant fibers that absorb water and produce the bulk necessary for the digestive tract to perform naturally. Psyllium fiber is found in many commercial products such as Metamucil, Per Diem and Konsyl. The regular product contains a fair amount of sugar, so it may be preferable to use the sugar-free products. Most pharmacies carry a generic brand at significant cost savings. Citrucel (hemicellulose) and Equilactin (polycarboxisal) are other bulking agents that can be used. These fiber supplements, in conjunction with foods, offer an easy way to reach the fiber goal of 20 to 35 grams per day.

Prevention of Colon Polyps - Cancer

The colon is the large intestine (bowel). It begins where the small intestine ends, near the appendix inside the right lower abdomen. The colon extends in a wide loop, up the right side to the bottom surface of the liver, and across to the left side of the abdomen where it turns down connecting finally to the rectum. Its main function is to solidify stool by reabsorbing as much of the water from the liquid stool that enters it. And, of course, it stores formed stool until it can be evacuated through the rectum.

Polyps And Cancer

Polyps are growths that form on the inside lining of the colon. They are usually shaped like mushrooms or dome-like buttons, and vary in size from a tiny pea to larger than a plum. While colon polyps start out as benign tumors, certain types of polyps (called adenomas or adenomatous polyps) may turn into cancer. The risk is greater as the polyp gets larger, however polyps are rather slow growing. It may take five years or more for a polyp to reach ½ inch in size. If an adenomatous polyp does turn into cancer, it may take five to ten years or more to reach that stage.

Colon cancer is very common, occurring in over 150,000 people in the United States each year. More than 90% of the patients can be cured if the cancer is detected and removed at an early stage. Adenomatous polyps can be removed before they become cancerous with a procedure called colonoscopy. A lighted flexible tube is inserted into the colon, allowing the physician to see the inside of the colon. Various accessories can also be passed through the tube to remove any polyps that may have formed. This procedure is usually done in an outpatient setting, with light sedation.

Causes And Risks

The complete cause of polyp formation and colon cancer is unknown, but it is known that heredity plays a role. Certain genes seem to prevent colon cancer from developing. Some people may lose these protective genes. This genetic deficiency can be inherited. A person whose parents, brothers or sisters have colon cancer is at greater risk of developing it. There is a also risk (but to a lesser degree) if uncles, aunts and grandparents have had the disease. Therefore, everyone with a family history of polyps and colon cancer should be evaluated by there physician and examined regularly.

Lifestyle and some medical conditions can increase the odds of developing colon polyps and cancer. A low fiber diet appears to contribute to the development of colon cancer. The rate of colon cancer increases in people after the age of fifty, as well as in people who have ulcerative colitis for a long period of time. Also, females who have a genital or breast cancer are at increased risk of developing colon cancer.

Prevention

Diet seems to be important in preventing colon cancer. Rural residents in Africa and India rarely develop colon polyps or cancer. Their diets are high in unprocessed grains (the bran or fiber is not removed) and low in meat. However, when these people move to westernized societies and adopt the typical western diet, over time they develop the same incidence of colon polyps and cancer. It appears that adopting a diet with less meat and at least 20 to 30 grams of fiber a day could play an important role in reducing the risk of developing polyps and colon cancer.

Too much meat in the diet is harmful because the fat, when broken down by the body's digestive juices, changes into compounds called carcinogens. These compounds are known to cause colon cancer in some animals. Diets high in fiber and roughage produce bulky stools. It is likely that large, bulky stools help to sweep the colon of carcinogens and harmful bacteria.

Fiber is the indigestible part of plants. Insoluble fiber does not dissolve in water. It adds bulk to the stool and regulates movement of the stool through the bowel. Wheat bran is a good source of insoluble fiber. Soluble fiber absorbs great quantities of water in digestion, and becomes gelatinous. Soluble fiber is found in such foods as oats, barley, brown rice, legumes, apples, strawberries and carrots.

There is also stool bulking agents available in drugstores which contain a soluble fiber called psyllium mucilloid, from a plant commonly grown in India. These products go by trade names such as Metamucil and Konsyl. There are also generic forms available. They are useful in treating irregularity, some diseases involving the intestinal tract (such as irritable bowel syndrome and diverticulosis), and probably in preventing polyps and colon cancer.

If there is a problem including enough fiber in the diet, use the following recipe for a low-calorie fiber supplement. Buy miller's wheat bran from a health food store and a Nutrasweet® psyllium mucilloid product from the drugstore. Take a heaping tablespoon of each in 6 to 8 oz of water or juice, twice a day. This formula contains 20 grams of soluble and insoluble fiber.

Calcium is one of the most common minerals in the body. It is necessary for bone strength and for many of the body's important chemical processes. For example, it is important in regulating the growth of cells. Animal studies have found that a lack of calcium leads to excessive cell growth in the colon. It is not clear if calcium has cancer preventive benefit for humans. Still, since it is important to the body in so many ways, everyone should get enough calcium in the diet. All adults should have 1000 mg per day. After menopause, females have a greater risk of osteoporosis (loss of calcium causing bones to weaken), and they should have 1500 mg of calcium a day.

A quart of milk a day does a good job of providing adequate calcium. Most people do not drink a quart of milk everyday, but there are other sources of calcium. Remember that some foods, such as puddings and custards, are prepared with milk. All dairy products (such as cheeses and yogurt), shellfish, seafood and many leafy green vegetables also contain calcium. However, the calcium in leafy vegetables is not as available for use by the body as calcium in milk. Some people on low calorie or special diets may not be able to get enough calcium in their diets. In these cases, the physician can recommend a calcium supplement. Calcium carbonate or calcium citrates are the best because they provide the most available calcium.

Aspirin is a miraculous drug. It relieves pain and fever and is good for heart patients because it things the blood. Now, medical studies show that the incidence of cancer of the esophagus, stomach, colon and rectum are less in those people who take aspirin regularly. It is known that prostaglandin (a hormone-like substance produced by the body) may promote excessive or abnormal cell growth in the intestine. Aspirin appears to interfere with prostaglandin, which may account for its role in preventing colon cancer.

How much aspirin is enough? A regular adult aspirin contains 325 mg. The effective dose for blood thinning or colon cancer prevention is probably in the range of 150 mg a day. One children's aspirin contains 80 mg. Some manufacturers are now making 150 to 180 mg tablets. There is one caution; aspirin can cause stomach ulcers in some people. Therefore, even in low doses, it should be taken with the approval of a physician.

In Summary…

Each person is unique and should be evaluated by a physician for the treatment of any medical condition or disease. In general, however, the following are important actions to follow in preventing the development of colon polyps and cancer:

• Fiber - 20 to 30 grams a day in the diet and/or as supplements.
• Calcium - 1,000 to 1,500 mg of calcium and/or as supplements.
• Aspirin - at least 150 mg of aspirin a day, or a 325 mg tablet every other day.
• Colonoscopy - for those with close relatives who have had colon polyps or cancer.
• Colon polyp removal - to prevent development of colon cancer.