Why Do We Need Dietary Fiber?

By: Dr. Magdy Badran

CAIRO, March.1(SEE) - Dietary fiber, also known as roughage or bulk, is the indigestible part of plant foods. It is a type of carbohydrate but, unlike other carbohydrates, it cannot be broken down into digestible sugar molecules.

Dietary fiber travels through the digestive system, absorbing water along the way and easing bowel movements. It is commonly classified as soluble, which dissolves in water, or insoluble, which doesn't dissolve.

Soluble fiber is soft and sticky; it dissolves in water to form a gel-like material inside the digestive system. It helps soften stool, so it can slide through the gastrointestinal tract more easily. It tends to regulate the speed of digestion, and permit better absorption of nutrients.

Soluble fiber slows the conversion of carbohydrates to glucose and delays glucose absorption into the bloodstream. This helps prevent dramatic increases in blood sugar levels, which then helps insulin work better.

Soluble fiber lowers cholesterol by binding to it in the small intestine and cholesterol will exit the body through the feces.

Soluble fiber boosts the population of good bacteria in the gut, which is linked to improved immunity, anti-inflammatory effects, and even enhanced mood.There are four types of soluble fiber: pectin, beta-glucan, naturally-occurring gums and inulin.

Pectin is a viscous soluble fiber, present in fruits, vegetables, legumes, and nuts. It is a complex sugar (polysaccharide) found in plant cell walls that helps maintain their structure by binding plant cells together.

Pectin may aid in weight management, lower total cholesterol and block the formation of blood clots, which are a risk factor for heart disease.

Pectin may reduce diarrhea, constipation, vomiting, acid reflux and lead toxicity. Pectin is prebiotic, that increases good bacteria in the colon and block the growth of harmful colon bacteria. The fruits containing the most pectin are citrus fruits, especially grapefruits, lemons, and oranges. The majority of the pectin resides in the citrus peel, but the pulp also contains some.

Beta-glucan is a soluble fiber that helps make your immune system smarter. It is present in grains like oats, rye, and barley. Inulin is a soluble fiber, not digested or absorbed in the stomach. It goes to the bowels where good bacteria are able to use it to grow. Good bacteria improve bowel function and general health. Inulin is found in a wide variety of fruits, vegetables, and herbs, including wheat, onions, bananas, artichokes, and asparagus.

Good sources of soluble fiber include kidney beans, broccoli, spinach, zucchini, apples, oranges, grapefruit, grapes, prunes, oatmeal, and whole-wheat bread.

Insoluble fiber does not dissolve in water or gastrointestinal fluids and remains more or less unchanged as it moves through the digestive tract. Because it is not digested at all, insoluble fiber is not a source of calories.

Insoluble fiber promotes the movement of material through the digestive system and increases stool bulk, so it can be of benefit to those who struggle with constipation.

Insoluble fiber is literally a sponge. It speeds up the elimination of waste through the colon. When you eat insoluble fiber it sits in your colon and soaks up all of the excess cholesterol, carcinogens, toxins, and waste, several times more than its own size. Insoluble fiber is like a scrub brush; it scours the intestinal tract and colon clean.

Whole-wheat flour, wheat bran, nuts, beans and vegetables, such as cauliflower, green beans, and potatoes, are good sources of insoluble fiber.

A lack of fiber in our diets could be causing the deadly rise in allergies seen in recent decades. High fiber diet protects against allergies by changing gut microbes, changing the way some immune cells are produced in the bone marrow and lowering leaky gut.

Leaky gut is a condition that occurs due to the development of gaps between the cells that make up the membrane lining the intestinal wall. These tiny gaps allow substances such as undigested food, bacteria, and metabolic wastes, that should be confined to the digestive tract, to "leak" through the intestines and flood the bloodstream.

The foreign substances entering the blood can cause an autoimmune response in the body including inflammatory and allergic reactions such as migraines, irritable bowel, eczema, celiac disease, chronic fatigue, food allergies, and rheumatoid arthritis.

Eating a high-fiber diet protects health through the intake of fiber, antioxidants and other essential nutrients. Both forms of fiber have major health benefits. As most high-fiber containing foods usually have insoluble and soluble fiber, it is not necessary to be too careful about piding them up.

The recommended daily amount of fiber for women is 25 grams and, for men, it is 38 grams. Dietary fiber recommendations for children: age of the child in years + 5 g; or 0.5 g fiber/kg body weight/day, up to 35 g/day.