Natural fibers include those produced by plants, animals, and geological processes and can be classified according to their origin. Vegetable fibers are generally based on arrangements of cellulose, often with lignin: examples include cotton, hemp, jute,flax, ramie, sisal, bagasse, and banana. Plant fibers are employed in the manufacture of paper and textile (cloth), and dietary fiber is an important component of human nutrition. We will discuss about dietary fibers.
Dietary fiber or roughage is the indigestible portion of food derived from plants. It has two main components; Soluble and Insoluble.
Soluble fiber, which dissolves in water, is readily fermented in the colon into gases and physiologically active byproducts, and can be prebiotic and viscous. 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.
These are a few example forms of fiber that have been sold as supplements or food additives. These may be marketed to consumers for nutritional purposes, treatment of various gastrointestinal disorders, and for such possible health benefits as lowering cholesterol levels, reducing risk of colon cancer, and losing weight.
Soluble fiber supplements may be beneficial for alleviating symptoms of irritable bowel syndrome, such as diarrhea or constipation and abdominal discomfort. Prebiotic soluble fiber products, like those containing inulin or oligosaccharides, may contribute to relief from inflammatory bowel disease, as in Crohn’s disease, ulcerative colitis, and Clostridium difficile, due in part to the short-chain fatty acids produced with subsequent anti-inflammatory actions upon the bowel. Fiber supplements may be effective in an overall dietary plan for managing irritable bowel syndrome by modification of food choices.
One insoluble fiber, resistant starch from high amylose corn, has been used as a supplement and may contribute to improving insulin sensitivity and glycemic management as well as promoting regularity and possibly relief of diarrhea. One preliminary finding indicates that resistant corn starch may reduce symptoms of ulcerative colitis.
Dietary fiber types
Soluble fiber is found in varying quantities in all plant foods, including:
- legumes (peas, soybeans, lupins and other beans)
- oats, rye, chia, and barley
- some fruits (including figs, avocados, plums, prunes, berries, ripe bananas, and the skin of apples, quinces and pears)
- certain vegetables such as broccoli, carrots, and Jerusalem artichokes
- root tubers and root vegetables such as sweet potatoes and onions (skins of these are sources of insoluble fiber also)
- psyllium seed husks (a mucilage soluble fiber) and flax seeds
- nuts, with almonds being the highest in dietary fiber
Sources of insoluble fiber include:
- whole grain foods
- wheat and corn bran
- legumes such as beans and peas
- nuts and seeds
- potato skins
- vegetables such as green beans, cauliflower, zucchini (courgette), celery, and nopal
- some fruits including avocado, and unripe bananas
- the skins of some fruits, including kiwifruit, grapes and tomatoes
Fiber is able to reduce blood sugar and cholesterol, can help you avoid hemorrhoids, even prevent colon cancer. Furthermore, they normalize bowel’s function. It’s good for women to consume about 25 grams fiber per day, men between 35 and 40 grams.
Find dietary fiber in common foods
Here is a list of some of the best foods containing fibers:
It offers a great combination of antioxidants and nutrients. Half a cup of corn grains contains about 2 gr. fibers. Popcorn also contain lots of antioxidants – almost twice more than many fruits.They also contain plenty of fiber. Three large bowls of popcorn contain 3-5 gr. of fibers.
It is rich in protein, iron and fiber, as well it is a very good source of potassium. One cup of beans covers 25% of the daily requirements of the body.
One cup contains 15 gr. fibers and about 15 gr.protein. These small grains are powerful antioxidant with a high content of flavonoids and plant pigments. When you eat foods high in fiber, it is good to drink more water, at least two liters a day. This allows fibers to pass through the digestive tract without difficulty, while cleansing it.
It is rich in fiber and antioxidants. One cup of chickpeas contains about 8 gr. fibers.
A great source of fibers- 2 tablespoons contain about 2 grams of fiber, and the whole fruit contain about 10 grams. Avocado is also an excellent source of mono and polyunsaturated fats. It lowers cholesterol and reduce risk of heart disease.
It is very useful for heart, stabilizes blood sugar, strengthens immunity and can protect you from breast cancer in menopause.
A cup of it contains approximately 3-5 gr. fibers. Consuming several portions of brown rice weekly, reduces the risk of type 2 diabetes by 17%.
Whole grain bread
It is interesting that wheat preserves its nutrients and it is rich in high fiber, as opposed to white bread, where the outer shell of the grain with the germ is removed, which is the most valuable part.
In a glass of lentils are contained 15.6 gr. fibers. Moreover, it is a great source of protein, vitamins, iron and other minerals.
Pears are rich source of fiber, but only if eaten with the peel. One medium pear contains 5.5 gr. of fibers.
One cup of raspberries can provide one-third of your daily fiber requirement. They are also a powerful antioxidant.
One cup of peas contains 16.3 gr. of fibers, but if it frozen – 8.8 grams.
It is known for its anti-cancer properties, one cup contains about 5 gramsf fibres.
You should not deny yourself of this precious fruit. Furthermore, it contains many fibers (one medium-sized apple contains about n4.4 gr. of fibers). It has many beneficial phytochemicals.
Take a quarter cup of almonds daily, because they contain about 170 calories and 3 gr. of fibers.