Dietary fiber comes from the indigestible portions of the plant; foods are categorized based on their water solubility. Soluble fiber, such as non-starch polysaccharides, cellulose, dextrins and inulins, is fermented by the bacteria in your colon into gases and metabolic byproducts. Insoluble fiber has the ability to extract water throughout your digestive system into your food bolus and is not fermented.
Importance of Fiber
Having enough dietary fiber is an important aspect of healthy living, for the following reasons:
- Appetite control: Both soluble and insoluble fiber add bulk to your food so you feel fuller, and they make you less likely to overeat.
- Stabilize blood sugar level: Soluble fiber attracts water during digestion and becomes gelatinous. This traps the sugar molecules so your body is not as responsive to the sudden rise of sugar levels after a meal, and in turn, slows down the absorption of glucose. This sugar control ability of soluble fiber makes it particularly beneficial for diabetics.
- Lowers cholesterol level: Soluble fiber has been proved to help reduce your risks of cardiovascular diseases such as atherosclerosis. During digestion, soluble fiber binds to bile acids so that they are less prone to enter your system. This inhibits your liver from synthesizing plaque causing triglycerides and LDL.
- Promotes digestive health: Fermentation of soluble fiber in your gut produces short chain fatty acids. These anti-inflammatory compounds have been shown to effectively reduce the symptoms of irritable bowel disease, diarrhea and or constipation. Short chain fatty acids can reduce the pH of your colon. A more acidic condition better protects your colon lining from the formation of polyps and tumor cells.
- Reduces food transit time: Insoluble fiber continuously absorbs water into your intestines during digestion. This not only increases the bulk of food, but also speeds up the movement of food in your intestines and softens your stools. These benefits make insoluble fiber effective in maintaining bowel regularity, as well as in the prevention and treatment of constipation.
Daily Fiber Needs
Surveys have shown that most Americans are not taking enough fiber to meet the standard for healthy living. On average, your daily recommended intake of dietary fiber is 25 grams, but some studies have shown that you should take as much as 35 grams of fiber everyday for better health.
Taking too much dietary fiber can also be problematic. Over time, taking in too soluble fiber can lead to a buildup of gases in your colon, and can cause bloating and flatulence. Insoluble fiber overdoses can cause diarrhea.
Sources of Dietary Fiber
Both soluble and insoluble fiber are plant-based in nature. All fruits, vegetables, whole grains, nuts and seeds are rich sources of fiber. Soluble fibers are especially high in legumes, oats, barley and berries, while insoluble fibers are more abundant in nuts and seeds, wheat and corn bran and skins of fruits.
In addition, manufactures such as Yoplait, Activia and Fiber One have extracted fiber from chicory and incorporated it into yogurts, cottage cheese and fortified cereals. Some Fiber One cereals can contain as much as 57% of dietary fiber in just ½ cup of cereal.
Keep fiber in mind when you plan your diet. It helps to give you a better heart, better bowel and an overall better body.