Image Caption : Soluble Fiber Helps Eliminate Cholesterol : This image shows a woman eating an apple - which contains soluble fiber. She has visible anatomy which focuses on the digestive tract. Soluble fiber acts like a cholesterol "sponge" by soaking up cholesterol-laden bile salts in the small intestine and eliminating these salts along with waste. Removing harmful cholesterol from the body decreases the amount of bad cholesterol collecting on the walls of the arteries, where it could increase the risk of heart attack and stroke. Soluble fiber can be found in a variety of grains, fruits, and vegetables.
Also called: Bulk, Roughage
Fiber is a substance in plants. Dietary fiber is the kind you eat. It's a type of carbohydrate. You may also see it listed on a food label as soluble fiber or insoluble fiber. Both types have important health benefits.
Good sources of dietary fiber include
- Whole grains
- Nuts and seeds
- Fruit and vegetables
Dietary fiber adds bulk to your diet and makes you feel full faster, helping you control your weight. It helps digestion and helps prevent constipation. Most Americans don't eat enough dietary fiber. But add it to your diet slowly. Increasing dietary fiber too quickly can lead to gas, bloating, and cramps.
Centers for Disease Control and Prevention
Dietary fiber or roughage is the indigestible portion of food derived from plants. It has two main components:
- Soluble fiber, which dissolves in water, is readily fermented in the colon into gases and physiologically active byproducts, and can be prebiotic and viscous. It delays gastric emptying which in turn can cause an extended feeling of fullness.
- Insoluble fiber, which does not dissolve in water, is metabolically inert and provides bulking, or it can be prebiotic and metabolically ferment in the large intestine. Bulking fibers absorb water as they move through the digestive system, easing defecation.
Dietary fibers can act by changing the nature of the contents of the gastrointestinal tract and by changing how other nutrients and chemicals are absorbed. Some types of soluble fiber absorb water to become a gelatinous, viscous substance which is fermented by bacteria in the digestive tract. Some types of insoluble fiber have bulking action and are not fermented. Lignin, a major dietary insoluble fiber source, may alter the rate and metabolism of soluble fibers. Other types of insoluble fiber, notably resistant starch, are fully fermented. Some but not all soluble plant fibers block intestinal mucosal adherence and translocation of potentially pathogenic bacteria and may therefore modulate intestinal inflammation, an effect that has been termed contrabiotic.
Chemically, dietary fiber consists of non-starch polysaccharides such as arabinoxylans, cellulose, and many other plant components such as resistant starch, resistant dextrins, inulin, lignin, chitins, pectins, beta-glucans, and oligosaccharides. A novel position has been adopted by the US Department of Agriculture to include functional fibers as isolated fiber sources that may be included in the diet. The term "fiber" is something of a misnomer, since many types of so-called dietary fiber are not actually fibrous.
Food sources of dietary fiber are often divided according to whether they provide (predominantly) soluble or insoluble fiber. Plant foods contain both types of fiber in varying degrees, according to the plant's characteristics.
Advantages of consuming fiber are the production of healthful compounds during the fermentation of soluble fiber, and insoluble fiber's ability (via its passive hygroscopic properties) to increase bulk, soften stool, and shorten transit time through the intestinal tract. A disadvantage of a diet high in fiber is the potential for significant intestinal gas production and bloating.
The material on this site is for informational purposes only and is not intended as medical advice. It should not be used to diagnose or treat any medical condition. Consult a licensed medical professional for the diagnosis and treatment of all medical conditions and before starting a new diet or exercise program. If you have a medical emergency, call 911 immediately.