What is Dietary Fiber?

There are two main types of fiber – insoluble and soluble.

Insoluble fiber

Insoluble fiber, also known as roughage and bulk, does not dissolve in water but paradoxically hangs onto water in the large bowel. This creates a large, soft and bulky stool. It promotes regularity and seems to be associated with a reduced chance of colon polyps and perhaps even cancer, as cancer inciting agents are swept through the bowel in a more regular manner. In addition, it may promote weight loss and enhance diabetic control. Foods that are high in insoluble fiber are:

• whole wheat bread and baked good
• wheat bran
• whole grain breads
• fruits and vegetables, especially the skins
• peanuts
• Brazil nuts
• popcorn
• brown rice

Soluble Fiber

Soluble fiber does dissolve in water. In the colon, it provides food for the enormous number of bacteria that thrive there and, in so doing, provides many health benefits. These fibers also promote regularity by increasing the growth of colon bacteria.  Foods that are high in soluble fibers are:

• oats in any form – cereal, muffins, etc
• apples, oranges, grapefruit, peaches, concord grapes
• prunes, pears, cranberries
• beans
• beets
• carrots
• sesame seeds
• psyllium (found in supplements and some cereals)

Importance of Dietary Fiber

In the distant past, we humans had only irregular access to wild animals and fish for protein. Instead, we relied on plants for most of our sustenance. Fossil studies have shown that our fiber intake was on the order of 50-100 grams a day. Even today in rural Africa, the average intake of plant fiber and coarse grains is 50 grams or more per day. Now, in our modern world with ready access to cheap animal protein and processed food, our fiber intake has dropped dramatically to 5-10 grams a day. Well, one might say, so what? The answers to that question are now coming in, like a tidal wave one might say.

For starters, consider this. Many of the diseases of the colon – diverticulosis, polyps, cancer, ulcerative colitis, and Crohn’s disease – are modern disorders, which have occurred coincident with a tremendous drop in our fiber intake. These same rural Africans, even to this day, seldom have these disorders, but they do when they consume our Western diet. Hmm, that is food for thought, isn’t it? More importantly, the science of how the colon functions, especially the incredible mix of bacteria within it, is now being uncovered. What has become increasingly clear is that:

• 5-10 grams of fiber a day is not healthy
• 20-30 grams is healthy in many ways
• both soluble and insoluble fibers are necessary for this well being

The Prebiotic Fibers

The soluble prebiotic fibers are latecomers in the science of fiber. It was scarcely 20 years ago that they were first discovered in the plant world. Now, we know a great deal about them. The best known prebiotics are inulin and oligofructose. These two are part of the soluble fiber group meaning they dissolve in water and are used by colon bacteria as nourishment. In a relatively short period of time, medical science has found that these prebiotics fibers likely: increase the growth of good colon bacteria decrease the growth of bad colon bacteria increase absorption of calcium and magnesium reduce blood triglyceride increase bone density improve blood sugar control enhance the colon’s own robust immune system decrease or stop the malodorous sulfide smell of flatus and, of course, improve bowel regularity Europeans eat 2-3 times the amount of inulin and oligofructose as North Americans do. These two plant fibers have been found in over 36,000 plants in the world so our ancestors likely got a healthy dose. We find these two fibers in: wheat onions garlic bananas artichokes leeks Jerusalem artichokes dandelions Commercially, they come from chicory root. We at Jackson GI Medical provide them in our products. For a full essay on prebiotics please click here.

The Top 12 Benefits of Prebiotics 1. Increase Probiotic Growth 2. Improved Bowel Regularity 3. Increase Calcium Absorption 4. Increase Bone Density 5. Enhance Immune System 6. Reduces Colon Polyp and Cancer Factors 7. Reduce Triglycerides Level 8. Reduce Allergies and Asthma 9. Control Appetite and Weight 10. Increase Good Colon Bacteria 11. Decrease Bad Colon Bacteria 12. Decrease Flatus Smell Sources of Prebiotics wheat onions garlic bananas artichokes leeks Read More About Prebiotics >

Fiber and Colon Diseases

Those of us who study the fiber field are quite convinced that our modern diet, with its extremely low fiber intake, is strongly related to many of the modern diseases of the colon. After all, these diseases have occurred over the same time as our fiber intake has fallen dramatically. The medical research on many of the following disorders is very suggestive as it relates to fiber. In the end, increasing fiber intake is like insurance. You can’t get insurance the day before you die. The same can be said for fiber. There is so much research to support increased fiber in the diet that you just don’t want to wait for the 100% sure, definitive proof, which may never come. You may select the disorder below in which you have an interest. One click will give you my description of the disease. The other will give the standard and, in some cases, my own additional slant on the recommended diet. 

Good Fiber Advice

 < Back to Top > 

According to all the expert fiber gurus, the basic recommendation for fiber intake is between 25-35 grams a day, depending on your age, sex, weight and the total calories you eat each day. Count the grams of fiber periodically to see where you stand. Check out the Fiber Content of Foods. Be sure to count both insoluble and soluble fiber. 

More is usually better. Your colon loves fiber. If I can convince you to love your colon, you will do the right thing and feed it enough fiber. Do it gradually. Too much soluble fiber initially may give you bloating and excessive flatus. Your gut usually accommodates a gradual increase. 

Eat the recommended five servings of fruits and vegetables each day. Make different choices during the week, being sure to select the colored veggies for their antioxidant content.

Select whole grains in breads, cereal and baked goods – whole wheat, wheat bran, oats, barley, brown rice, rye and bulgar. Amaranth is a little known but delicious grain with a huge amount of fiber. You can get cereals with amaranth at health food stores or perhaps the “organic” section of the standard food stores. Avoid white bread and baked goods.

Legumes are luscious. These include most beans, peas, soybeans, nuts, even peanuts (which are not really nuts). There is lots of good fiber in these. 

Fiber supplement. Some rely on these supplements to keep regular. There is nothing wrong with this. We think our products fit in very well with a high fiber diet.

For Jackson GI Medical products, click here.