High Fiber Diet


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High Fiber Diet

Purpose Dietary fiber only comes from plants and grains, never from animal foods. it helps to maintain a plant structure. Cellulose, hemicellulose, polysaccharides,...


Lactose-Free Diet

Purpose Lactose is the simple sugar found in milk and milk products. It can also be found in a variety of other foods and even as a filler in some pills and capsules....



Dietary fiber only comes from plants and grains, never from animal foods. it helps to maintain a plant structure. Cellulose, hemicellulose, polysaccharides, pectins, gums, mucilages and lignans are all dietary fibers, mostly of interest to the plant chemist. More broadly, most fiber can be broken down into insoluble and soluble fiber. Neither of these, nor in fact any fiber, is digested by the body in the small intestine. Rather, they arrive in the colon, where they exert a profound function for the body and, indeed, our very health.


Function of the Colon

Every field of medicine has progressed enormously over the past 10-15 years. Our understanding of the colon and how if functions is no exception. What we now know about the colon and how it functions is simply staggering to us gastroenterologists who, in medical school, thought we knew all there was to know about the colon. Back then, it was viewed as a container that dehydrated liquid stool that entered it, stored it and then evacuated the stool when convenient.

But this is only a small part of what the colon does even though it is the only one that the average person will see and feel. Do I have a soft, regular bowel movement every day? If so, my colon must be functioning okay. Well, not so fast. Now we know that the colon is a hot bed of thriving community of densely-packed bacteria. We know that most of these bacteria are our friends and when they are fed purposely with the right foods and plant fibers that they need, some truly spectacular health benefits occur.

The Importance of Dietary Fiber

There are now at least 13 known, medically researched health benefits when the right types of fiber are ingested. These benefits can and do occur in the otherwise healthy person when adequate amounts of fresh vegetables, fruits, whole grains or fiber supplements are used. More specifically, most of these benefits occur when significant amounts of the newly discovered prebiotic fibers are consumed.


Prebiotic Fiber Health Benefits

  • Increase probiotic growth
  • Improve bowel regularity
  • Increase calcium absorption
  • Increase bone density
  • Enhance immune system
  • Reduce colon polyp/cancer factors
  • Reduce triglyceride level
  • Reduce cholesterol level (only psyllium fiber)
  • Reduce allergies and asthma
  • Control appetite and weight
  • Increase good colon bacteria
  • Decrease bad colon bacteria
  • Decrease flatus smell


Nutrition Facts

Fiber is not digested as a calorie as it moves through the small intestine. However in the colon, under the influence of the bacteria that live there, some beneficial energy and calories are produced. However, this is a very small amount and the health benefits of dietary fiber far outweigh the few extra calories produced in the colon.

Fiber can best be understood as insoluble and soluble. Insoluble fiber does not dissolve in water and is not used by colon bacteria as a food or fuel. However, it does hand onto water avidly and so promotes regularity and a soft bowel movement.

Soluble fiber, on the other hand, does dissolve in water, and to varying degrees, is the fuel that promotes the best growth of the best colon bacteria. The soluble fibers, which by far have the most science behind them, are called prebiotics. These prebiotics, especially the ones known as inulin and oligofructose (FOS) have the most research.

You are referred to Prebiotics for further details on this key part of the fiber picture. To get a list of any foods and of the insoluble and soluble content.


Fiber in the Healthy

Eating fresh vegetables, fruits and whole grains is a mantra we have all heard forever – from our mothers, friends and the media. In the past, we didn’t know why. Now we do. All plant material is a mix of soluble and insoluble fibers of many types and different percentages. When a variety of these foods are eaten on a regular basis, you are almost certain to get the right combination of insoluble, soluble and prebiotic fibers. 25-35 grams a day is the goal. When this happens and when other health parameters are followed – i.e. no smoking, adequate exercise, no stress, etc., then the best outcome and health benefits can be expected. Studies on people who consume this type of a high fiber diet as part of their overall health care plan simply live better and longer than those who do not.

Fiber in Irritable Bowel Syndrome (IBS)

IBS is a chronic disorder of the bowel, principally the colon. It is now known that there are numerous factors that contribute to IBS and its symptoms, such as genetics, diet and stress. Recent research has shown that the bacterial makeup within the colon is different in IBS people than it is in others. This means that there are different bacterial species and numbers of bacteria in the colon. We still do not know what this means. However, we do know that the bacteria within the colon rely on the foods we eat and especially the food fibers for their own health. So, changing the colon bacterial makeup may make sense for some IBS patients. This needs to be done carefully so as to avoid gas build-up.

Fiber and Colon Polyps/Cancer

A significant factor leading to colon polyps and cancer is in your genes. You can not change your genes so if anyone in your family or blood relatives has had colon polyps or cancer, you need to see your physician and get surveyed for this preventable cancer. Colon cancer can be prevented if polyps are removed before they get big. It can be cured if a colon cancer is found early. Diet is next. The regular ingestion of 25-35 grams of fresh vegetables, fruits and whole grains is the key. When significant amounts of plant fibers are ingested, particularly the newly discovered prebiotic fibers, it seems to lead to a reduction in certain carcinogenic (cancer causing) factors in the colon. This has been shown in animal and some early human studies.

Fiber, Cholesterol and Triglyceride

We have known for many years that a diet low in saturated and trans-fats, as well as high in fresh vegetables, fruits and whole grains is critical to maintaining a good cholesterol and triglyceride blood level. Other health factors such as not smoking, exercise, normal weight and lack of stress are equally important. Regarding fiber, we know that two fibers are helpful in managing and preventing heart disease and atherosclerosis.

Psyllium is a plant fiber that has long been used as a bulking agent. It comes in many dietary supplements over the counter. It has been found that when 7 grams of psyllium is ingested each day, the blood cholesterol can fall. So, if the cholesterol benefit is what you want, then you need to increase the dose. Triglyceride levels generally fall when weight is reduced and simple carbohydrates and sugar are restricted in the diet. Prebiotics can contribute to triglyceride control.



Fiber Gas and Flatus

Most colon gas and flatus comes from the bacteria that grow in the bowel. The normal passage of flatus is 15-20 times a day, less in females and in those who just eat less food. However, there is now a great deal known about which bacteria produce the gases. Some make the odorless hydrogen and methane gases. Others make the smelly sulfide gases. Fiber can be a factor here.

Fiber and Diverticulosis

Prolonged, vigorous contractions of the colon, especially in the left side of the abdomen, may result in diverticulosis. This increased pressure causes small and eventually large ballooning pockets to form. When these pockets become infected, diverticulitis occurs, a nasty infection. In the past, physicians thought that seeds, nuts and popcorn could rattle around inside these pockets and cause damage. I, personally, never bought into this idea and had always recommended these foods because of their high fiber content. Now, science has shown that seeds, nuts and popcorn not only do not cause diverticulosis and its problems but also are good for you as a fiber source. The important consideration for patients with diverticulosis to know is that food and fiber supplements increase stool bulk and thereby reduce the colon pressure and development of diverticulitis.


Fiber and Inflammatory Bowel Disease (Crohn’s Disease and Ulcerative Colitis)

In the past, there was not too much we could tell these patients about their diet. We would recommend trying almost any food and then evaluate the individual response. If the symptoms did not worsen, then it was okay to use that particular food. Now, there is considerably more known about diet in dealing with Crohn’s disease and ulcerative colitis. In particular, plant type foods such as fruits, vegetables, and whole grains, seem to be helpful. The newly discovered prebiotic plant fibers, especially, have come under scrutiny by medical researchers. In some instances, these prebiotic fibers may show benefits for patients with inflammatory bowel disease conditions.


Fiber Supplement

Most people take fiber supplements for one reason only. They want to have bowel regularity including a soft, easy-to-pass bowel movement. Beyond this, they simply don’t think too much about their lower bowel or colon. Soft regularity is a goal that every gastroenterologist wants for their patients. This occurs when enough fiber, especially the insoluble type, is ingested. This includes the fiber, psyllium, which is not available as a food but only as the fiber supplement. Psyllium contains mucilage and, along with most insoluble fibers, retains water and so promotes soft regularity. However, the soluble fibers play a role here as well. These fibers, including the newly discovered prebiotic soluble fibers, promote regularity by dramatically stimulating the growth of good colon bacteria. You add the bulk provided by the growth of good colon bacteria to that of water retaining insoluble fiber and you get the full fiber benefit.

The prebiotic soluble fibers provide a host of health benefits you cannot feel but are occurring nevertheless. These act very much like vitamins in the sense that you cannot feel them working in your body, but you know that science has shown their good health value.


Special Considerations

Select these foods for maximal fiber benefit.

  • Whole grain breads and rolls so as to get the fiber along with its vitamins and minerals.
  • Fresh fruits, including skin and pulp. Wash fruits thoroughly to remove any residual pesticides or buy organic.
  • Dried or stewed fruits, such as prunes and apricots.
  • Root vegetables such as carrots, turnips and yams, which are also rich in antioxidants.
  • Cruciferous fresh vegetables such as broccoli, Brussels sprouts and cabbage. These high fiber foods also contain sulforaphone , a strong anti-cancer agent.
  • Cereals – Many cold cereals will contain sugar, evaporated cane juice, which is nothing but sugar, or high fructose corn syrup (HFCS). These are added calories that are used simply because the public will usually not buy a non-sweetened cereal. Read the labels. I would recommend avoiding cereals with these sugary sweeteners or other ingredients you do not recognize.
  • Finally, when 25-35 grams of total fiber a day is hard to reach, you can always use a fiber supplements for significant amounts of fiber with both health benefits as well as soft bowel regularity.



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