A high fiber diet is good for you. Everyone knows that. But in recent years the flurry of claims and counterclaims about insoluble fibre, soluble fibre, oat bran versus oat bran and fresh fruit versus whole wheat bread have thrown what once seemed a simple recipe for health into a bit of a mess. It is no longer clear what the word”fiber” method.
For example, most people think that fiber is indigestible. It is true that fiber, the structural part of plants, cannot be broken down by the normal digestive juices in the stomach and small intestine. But it can be broken down, at least in part, in the large intestine, by the millions of bacteria that colonize other parts of our bodies. Most of the poop actually consists of these bacterial corpses.
Fiber is not a single unit. There are several types of fiber in the diet, and each has a different effect on the body as it travels through the digestive tract.
Insoluble fiber is cellulose. It is sometimes called crude fiber and makes up only a small portion of the total fiber in the average diet. That soluble fiberlike the gums in oats and dried beans, and pectin, completely digested by bacteria in the large intestine, leaving acids behind that stimulate the intestinal walls to contract.
One type of dietary fiber, lignin, is nearly indigestible, but there is evidence that it helps the body get rid of it cholesterol by eliminating bile acids (one of the main functions of cholesterol in the body is to make these acids).
A high-fiber diet is useful in treating and preventing constipation. The acid produced during the digestion of fiber stimulates and accelerates the movement of food throughout the body, and the fiber itself absorbs water, giving it a large amount of waste.
There is also evidence that fiber can help prevent hemorrhoids, intestinal wall hernias, colon cancer, and possibly cardiovascular disease.
It is believed that by speeding the passage of food through the body, fiber can help remove bad toxins before they have a chance to cause disease, but there is also some evidence that the acids produced during digestion of fiber may act as a anti-cancer agent.
The picture is somewhat clouded by the fact that high-fiber diets are usually quite low in fat as well. Because high fat consumption is known to increase a person’s risk of developing cancer, it is unclear how much of the benefit from a high-fiber, low-fat diet is due to fiber and how much of it is from the low fat content.
There is some evidence that a high-fiber diet, along with low fat and sugar intake, can help diabetics control their disease. Fiber, which is found in some foods, such as oats and legumes, forms a gel on the surface of the stomach that helps slow the rate at which sugar enters the bloodstream.
Most people consume around 15g of dietary fiber a day. Nutritionists recommend that 30 to 40g would be a better target.
But there are dangers in eating too much fiber. Fiber absorbs iron and zinc as they pass through the digestive system, potentially depriving the body of these important nutrients. Bran by itself will not cure constipation. It needs water to make it swell and do its job and, in fact, if the bran is eaten without enough liquid to complete its healing, constipation can actually get worse. Unprocessed bran in large quantities can cause the cells lining the intestines to become damaged.
Anyone planning to start a high-fiber diet should do so gradually. A sudden shift to a high-fiber diet can cause the digestive system to rebel, resulting in wind, nausea, and even vomiting.
ideally, food fiber must be obtained from various sources. Foods especially high in fiber include baked beans (13g of fiber for a cup of beans), pumpernickel bread (5.6ga slices, compared to 2g for a slice of whole wheat bread), dried dates and figs, peas, pumpkin and raspberries. . Foods with very little fiber include cherries (0.4g in 10 cherries) and grapes (0.3g for the same amount).
Flour is relatively high in fiber, which means that most white bread contains about 0.8 g of fiber per slice (about the same as a tablespoon of sultanas). That’s not great, but it does mean that white bread isn’t actually the evil food it’s sometimes made out to be.
Variety is key when it comes to fiber. It’s much more enjoyable to get your daily requirement from a selection of fresh, unpeeled fruit and vegetables, along with some whole-grain bread, than to grind up a few tablespoons of unprocessed bran at breakfast. Look at it this way: one tablespoon of oat bran has 2.2g of fiber. An unpeeled apple has 2.5g. Which do you prefer to eat?
Reference:
http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/fiber/art-20043983
Nataliaa passionate health researcher and blogger who loves to learn, discover, and share tips on Lifestyle & Health.
