Fiber is probably one of the most misunderstood dietary components. Many people, even physicians, are confused about the different types of ﬁber, the beneﬁts, and how much fiber should be consumed. This article should help you better understand the role of ﬁber and its importance to your health.
What is Fiber?
Fiber is a polysaccharide, sugar-like substance that comes in hundreds of forms. Dietary ﬁber is the indigestible portion of plant foods found mainly in its outer layers. Fiber passes through the human digestive tract virtually unchanged, without being broken down into nutrients. Most people know the importance of ﬁber, but few really understand how to best integrate ﬁber into a diet.
Over a hundred years ago, a change in the way wheat was processed substantially removed the dietary ﬁber in ﬂour. Because of this, most of us only consume a small fraction of the amount of recommended daily ﬁber. In fact, the average American consumes only about 10% of the ﬁber that was part of a normal diet 100 years ago. The human body is well designed to accommodate many of the different types of ﬁber found naturally in foods. In fact, the National Academy of Sciences Institute of Medicine recommends 30-38 grams of ﬁber for men and 21-25 grams of ﬁber for women, each day.
Dietary ﬁbers are mostly soluble or insoluble. Fibers that dissolve in water (soluble) make a gel-like substance that may soften stools, hold cholesterol and fats, and lower blood sugar. Soluble ﬁbers promote increased growth of essential bacteria in the colon thereby increasing bulk. Some examples are fruits, wheat, leafy vegetables, oats, beans and substances such as celluloses, pectin, psyllium and gums. Fibers that do not dissolve in water (insoluble), bind water in the colon. This sponge-like effect bulks stools and binds materials such as bile and potential carcinogens. Examples of insoluble ﬁbers include whole grains, cereals, vegetables corn, rice, and bran. Both soluble and insoluble ﬁbers may help patients with irritable bowel syndrome, diverticular disease, heart disease, and obesity. They may also potentially reduce the risk of colorectal cancer.
How to take ﬁber:
High ﬁber foods are good for your health, but adding too much too quickly can promote intestinal gas, bloating and cramps. Increase ﬁber in your diet gradually over a few weeks including plenty of ﬂuids (6-8 glasses a day). This will allow your digestive system the appropriate time to adjust. The best sources of ﬁber are those found in foods. Eating a diet rich in ﬁber will incorporate varieties of ﬁber, both soluble and insoluble, that’s healthier than ﬁber supplements as they contain essential vitamins and minerals not found in supplements. However, some people may need supplements for certain medical problems if dietary changes do not supply enough daily ﬁber.
Many everyday low-ﬁber foods do have high-ﬁber alternatives, so make smart food choices. Also, it’s important to know that freezing, drying, and normal cooking do not signiﬁcantly alter the ﬁber content of most foods.