Fiber is a hot topic these days. Most Americans are not getting the recommended amount of daily fiber. Increasing dietary intake to 20-35 grams per day may have health benefits. Eating the recommended amounts of fruits, vegetables and whole grain can easily meet your nutritional needs for fiber.
Fiber provides structure to all plant food sources. Most fiber is composed of polysaccarhides. The bonds in polysaccarhides can not broken by human enzymes are therefore are not digested. Dietary fibers can be broken down into two main groups:
Soluable fibers and Insoluable fibers.
Soluable fibers are not digestable food components. Soluable fibers when mixed with water will form a gel. Soluable fibers can be digested by normal bacteria found in the colon. The bacteria breaks down the soluable fiber into fragments which can be absorbed and metabolized by cells in the lower gastrointestinal tract. Soluable fibers are commonly found in oats, barley, legumes, and citrus fruits. Soluable fibers have been found to protect against heart disease and diabetes. A diet high in soluable fibers will aid in lowering cholesterol levels. Delayed digestion attributed to soluable fibers will also lower blood glucose levels.
Insoluable fibers do not dissolve in water and they do not form gels. Insoluable fibers are mainly found in whole grains and vegetables. Individuals suffering from constipation can find relief by incorporating more insoluable fiber (and water) into their diet. Adequate amounts of insoluable fibers may help lower the risk of diverticulous, colon cancer and appendicitis.
Functional fibers are fibers that have been extracted from plants or manufactured and then added to foods or nutritional supplements. Functional fibers have beneficial health benefits and provide an added function in the food product. You may wonder what xanthan gum is on your food label. Xanthan gum is often added to food items such as salad dressings, refrigerated dough and dry mixes. In salad dressings, xanthan gum is added as an emulsifier to prevent the fats and oils from separating. Other examples include: cellulose gum, agar-agar, carob, and gum Arabic. Functional fibers can stabilize foams, thicken, improve texture and much more. The term total fiber on nutritional labels refers to the total of dietary fibers and functional fibers.
Resistant starch is classified as a dietary fiber. Like insoluable fibers and soluable fibers, resistant starch can not be digested. Resistent starch is commonly found in whole legumes, raw potatoes and unripe bananas.
Common fibers found in foods.
The most common fibers found in foods are cellulose, hemicellulose and pectic substances. Fibers found in foods are usually a mixture of both soluable and insoluable fibers.
Health benefits of fiber may include:
- Lowering cholesterol
- Improving the glycemic response
- Better blood sugar management
- Better feeling of fullness after meals
- Promoting weight loss or weight management
- Relieve from constipation
- Lower risk for heart disease, cancer, diverticulous, appendicitis, obesity and diabetes
- Stimulates bacterial fermentation in the colon
Getting too much Fiber.
As you have seen fiber getting adequate fiber in your diet can be benefits. Getting too much fiber in your diet can cause gas, bloating, abdominal and/or diarrhea. Excessive intakes of fiber may also lower the absorption of certain minerals.
Ask your doctor or a registered dietitian how much fiber is right for you.