Benefits of Fiber and its importance in the human body
Fiber properties depend on the type of fiber. Soluble and insoluble fiber properties are set out below.
Soluble and insoluble fiber
- It can decrease appetite by increasing the food volume without any corresponding increase in the calorific value (indigestible fiber) , thus leading to a feeling of fullness.
- Limits the changes in blood sugar levels by absorbing water and turning into a jelly-like, viscous substance during digestion, stopping the carbohydrates and slowing down the glucose absorption.1
- Decreases the risk of heart disease by lowering the level of cholesterol, including LDL.
- It regulates the blood sugar level and and thus can diminish the risk of developing diabetes and metabolic syndrome or can ameliorate their symptoms.
- May lessen the risk of colon cancer2 as it aids the maintenance of optimal intestinal pH3 and stimulates the production of short chain fatty acids in the intestines.
- Helps regular bowel habits, increasing the speed of passage of food through the digestive track.
- Helps with constipation problems by increasing the volume of ingesta.
- Increases the amount of toxins removed from the digestive track.4
Benefits of dietary fiber in detail
Regular consumption of fermenting fiber in products such as fruits and berries, vegetables, whole food products, nuts and seeds, decreases the risk of some of the most common world diseases such as obesity, diabetes, high cholesterol, circulatory diseases and ailments of the digestive system.5,6,7,8
The main action of fiber is to change the character of the contents of the digestive track and to change the absorption of the main nutrients and chemical substances.9,10 Fermenting fiber is of highest importance to human health, as it produces short-chain fatty acids when fermenting in the colon.
Soluble fiber binds bile acids in the small intestines which in turn lessens the chance of their absorption by the body and lowers the level of blood cholesterol.11 Soluble fiber weakens sugar absorption, prevents sudden changes of blood sugar level, and stabilises the blood lipids level. Consumption of insoluble fiber corresponds with a lower risk of diabetes although the precise mechanism causing this decrease is yet unknown.12
Clinical tests have shown that fiber helps in lowering the level of blood cholesterol, which is of great importance to a healthy circulatory system.13 It also decreases the risk of development of some cancers.14 Lignin, and most probably other similar products resistant to enzymatic degradation decrease the calorific value of food15 which is helpful in fighting obesity.
Vitamins and minerals
Fiber does not bind with minerals and vitamins and therefore does not affect their absorption. There is some evidence though that fermenting fiber aids the absorption of minerals, especially calcium.16,17,18 Some plant food products depress the absorption of minerals and vitamins, e.g. calcium, zinc, vitamin C and magnesium, but this is due to the presence of phytic acid and not fiber.16
Fiber in relation to digestive system diseases
Consumption of soluble fiber supplements helps ease the symptoms of Irritable Bowel Syndrome, such as diarrhoea or constipation as well as stomach pains.19 Probiotic soluble fiber such as inulin or oligosaccharides can help Inflammatory Bowel Diseases20, such as a Chrone’s disease,21 Ulcerative Colitis,22,23 and Clostridium difficile.24
Constipation and haemorrhoids
Insufficient fiber in the diet may interfere with bowel emptying. Faeces containing small amounts of fiber are dehydrated and hard which make passing difficult. This causes constipation and may lead to haemorrhoids or fissures25.
Fiber may help longevity
A study on 388 thousand of adults aged between 50 and 71 over nine years has shown that the death rate amongst people consuming the highest amounts of fiber was lower by 22%.26 Apart from a lower rate of heart disease related death, a fiber rich diet, especially a cereal diet, appeared to diminish the frequency of infectious diseases, respiratory tract infections and the risk of cancer death, especially amongst men.
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