What fiber is needed for the body – 7 facts about the benefits and harms
Fiber or dietary fiber is a coarse food that is practically not digested under the action of digestive enzymes and is excreted unchanged from the body. A person cannot extract valuable nutrients from it, but it is necessary for the smooth functioning of the gastrointestinal tract.
Exists two main types of fiber :
- Soluble. Such fiber is able to quickly absorb free liquid and increase in volume several times. It causes a feeling of satiety and has an effect on many types of metabolism.
- Insoluble. Does not interact with water, accelerates the movement of feces through the digestive tract and cleanses the body.
Both types of fiber are a "nutrient medium" for most representatives of the beneficial human microflora.
7 useful properties
Dietary fiber has a lot of useful properties for the human body, and especially for the work of the gastrointestinal tract. Below we will describe 7 proven facts about the benefits of fiber, as well as consider possible harm with links to official studies.
1. It is a food for beneficial bacteria
The human digestive system is constantly inhabited by about 100 trillion microorganisms, most of which are concentrated in the large intestine. Like any other living creatures, representatives of the microflora must also receive nutrients and energy.
Almost all proteins, fats and carbohydrates from food are absorbed before they reach the lower parts of the digestive tube.
But fiber is able, unchanged, to reach the habitats of &171;useful &187; microorganisms and become a source of nutrients for them. That's actually what fiber is needed by the human body for – it is food for beneficial bacteria.
According to Canadian research, dietary fiber increases the number of lactobacilli and bifidobacteria. There is also a positive effect on the number of representatives of the kingdom of bacteria such as Fermicutes.
According to scientists, the consumption of dietary fiber is one of the most effective and cheapest ways (compared with medical drugs and other therapies) to restore adequate microbiocenosis of the intestine .
An increase in the number of noble microorganisms has a positive effect on the work of the entire body. There is a decrease in blood glucose levels (especially on an empty stomach), maintaining the lipid profile at the proper level, improving the functioning of the immune system .
Bacteria are even able to influence the central parts of the nervous system. According to Irish scientists , an increase in the number of "useful" representatives of the microflora prevents the appearance of productive mental disorders and depression , increases the tolerance of psycho-emotional stress.
Against the background of the constant persistence of lacto- and bifidobacteria, there is a decrease in the incidence of infectious-inflammatory and autoimmune diseases of the digestive system (Crohn's disease, ulcerative colitis).
2. Promotes weight loss
Dietary fiber affects body weight through various mechanisms.
According to scientists from the USA, fiber causes a rapid onset of a feeling of filling the stomach and helps to reduce appetite.
In human experiments, in which food intake was not limited, but 14 g of dietary fiber per day was necessarily introduced into the diet, there was a natural decrease in the caloric content of the daily diet by 10%, as well as weight loss (2 kg in 4 months).
Proven that the abundance of fiber in the lumen of the digestive tract slows down the absorption of fats and a number of bile acids secreted with bile. As a result, the body receives less fat, even with significant dietary intake, which leads to a decrease in body weight.
Soluble fiber is the most useful for weight loss.
3. Slows down the rise of glucose in the blood
According to scientists from Germany, the consumption of dietary fiber leads to a slowdown in the absorption of all carbohydrates, especially those with a low glycemic index. As a result, with pronounced pathologies of blood sugar utilization, there is a slow rise in glucose after food consumption.
This feature is extremely important for patients with diabetes mellitus.
According to research , viscous dietary fibers have the greatest effect: legumes, flax seeds, asparagus and oats.
It is especially important to consume fiber for people whose diet is replete with a large number of carbohydrates due to various reasons (a special diet or an incorrect lifestyle).
4. Reduces cholesterol
Individual scientific studies emphasize that the intake of soluble fibers helps to reduce the level of total cholesterol and bring it to the proper values of its fractions.
As an example, you can give a study by American scientists . Eating only 2-10 g of dietary fiber leads to a decrease in total cholesterol, an increase in HDL (&171; beneficial&187; cholesterol) and a slight drop in TAG and LDL (&171;harmful&187; cholesterol).
Similar results make it possible to include fiber in the scheme of complex anti-atherosclerotic therapy in patients with high cardiovascular risk.
Increased intake of dietary fiber, according to experts , reduces the incidence of coronary heart disease, one of the most dangerous and common diseases.
5. Promotes the prevention and elimination of constipation
An important advantage of insoluble fiber is the prevention of constipation in children and adults.
Scientists claim that dietary fiber helps to increase the frequency of stools, cleanse the intestines of feces, and suppress symptoms such as painful and difficult defecation.
It should be noted that only insoluble dietary fiber has a laxative effect. Soluble fibers form a hydrogel, which, on the contrary, contributes to the retention of feces, activates the processes of fermentation and putrefaction.
Therefore, the approach to fiber intake in order to eliminate constipation should be competent and well thought out.
It is recommended to consult a specialist in advance to avoid adverse reactions.
6. Reduces the risk of colon and rectal cancer
One of the studies conducted in 2015, revealed that increased dietary fiber intake significantly reduces the incidence of colorectal cancer. The most pronounced anti-carcinogenic effect is observed in cereals and fruits.
Why is this happening? The positive effect is most likely due not only to the acceleration of the promotion of feces (rapid elimination of toxic metabolic products), but also to the powerful antioxidant properties that most plants are endowed with.
American scientists emphasize that the restoration of microflora plays a special role in reducing the risk of colorectal cancer, since it has a complex effect on metabolism at the level of the intestinal wall.
7. Reduces the risk of stroke
Irish research has found that fiber intake leads to a decrease in carotid artery stiffness from an early age. The effect is probably related to the effect on glucose and cholesterol metabolism.
The denser the walls of the arteries, the higher the risk of atherosclerosis and subsequent detachment of a blood clot, which can lead to acute impairment cerebral circulation .
Similar results were obtained in the works of Italian scientists. Experts recommend consume at least 25 g of soluble and 47 g of insoluble fiber daily to prevent the early onset of a formidable vascular complication.
Daily rate
According to scientific data, the dietary fiber intake rate is:
- For men &8212; about 38 g per day.
- For women – 25 g per day.
Statistics show that 95% of the population does not consume even this amount of fiber.
Sources
Fiber-rich foods are also called prebiotics .
The most rich in soluble fiber are such products: oats, Brussels sprouts, peas, beans, apples, citrus fruits (oranges, tangerines), nuts (especially almonds), flaxseeds.
The leaders in the content of insoluble dietary fibers are: wheat bran, rye and wheat flour bread, grain bread, Borodino bread, legumes (green beans), dark greens, root vegetables (radish, beetroot, carrot), the peel of any fruit.
Fiber is also drunk in the form of a dry powder mixed in water and taken in pharmacy capsules.
Harm from excessive consumption
But with excessive consumption of dietary fiber, a number of disorders may develop due to either increased motor function of the intestine, or, conversely, a delay in fecal matter and activation of fermentation and putrefaction processes:
- Flatulence;
- Spastic pain along the course of the large intestine (lower abdomen);
- Stool disorders by type of diarrhea or constipation;
- Weight gain (usually temporary);
- Development of intestinal obstruction;
- Critical decrease in blood glucose (relevant for diabetic patients taking hypoglycemic therapy).
Conclusion
Thus, dietary fiber has a lot of useful properties. They help to reduce appetite and maintain body weight at the proper level, prevent a number of menacing cardiovascular diseases (due to their effect on glucose and insulin metabolism, effects on the lipid profile and stiffness of artery walls).
There is also a positive effect on the digestive system: reducing the incidence of infectious and inflammatory, autoimmune and oncological pathologies.
If you develop any adverse reactions or doubt the need to consume increased amounts of fiber, it is recommended to consult a doctor.
