Fiber (dietary fiber, dietary fiber) plays an important role in the body. Fiber reduces the absorption of cholesterol, thus preventing cardiovascular disease, and lowers blood glucose levels, which should be appreciated by people with diabetes. In addition, fiber gives a feeling of satiety for a long time, thanks to which it will work well on a slimming diet. What other properties does fiber have? What foods are high in fiber?

Dietary fiber (dietary fiber)is a term for building components of plant cell walls that are not digested in the human digestive tract.

There are two types of dietary fiber with different effects:

  • soluble fiber
  • andinsoluble fiber .

In plant products, they appear together, but in different proportions.

Soluble and insoluble fiber

Fiber is divided into water-soluble and water-insoluble fractions. Insoluble fiber (cellulose, lignin), which plant cell walls are made of, acts as a filler.

Absorbs water but does not dissolve in it. Thanks to this, it softens the stool, increases its volume, accelerates intestinal peristalsis, regulating bowel movements.

Insoluble fiber works like a broom. They travel through the entire digestive tract virtually unchanged, eliminating residual residues.

Soluble fiber (gum, pectin) forms jelly in the intestines. It binds a large amount of water, swells in the stomach, stretches its walls, giving a feeling of fullness. It also delays the moment when the food leaves the stomach.

Soluble fiber fractions form a delicate gel that fills the stomach and covers the walls of the upper gastrointestinal tract, slowing the absorption of carbohydrates.

This type of fiber also helps cleanse the body of toxic waste products and heavy metals.

It inhibits diarrhea, reduces cholesterol, increases the excretion of fats in the feces, delays the absorption of triglycerides. Soluble fiber also supports the growth of beneficial bacteria in the gut.

Fiber and cardiovascular disease

In numerous scientific studies, the impact of dietary fiber consumption on the risk of systemic diseases was observedcardiovascular disease.

During the 10-year observation, about 100,000 people were examined. men and 245 thous. women. It was noticed that increasing the consumption of fiber in each of the studied groups by 10 g per day resulted in a reduction of 14%. the risk of developing heart disease, and also reduces by 27 percent. risk of death due to coronary diseases.

It has thus been proven that the increase in dietary fiber consumption is inversely proportional to the number of deaths caused by cardiovascular diseases, and such factors as:

  • gender,
  • age,
  • environmental factors,
  • physical activity

had no significant influence on the results obtained .¹

Dietary fiber protects the circulatory system in several ways: it reduces fat absorption, lowers cholesterol levels, limits the absorption of bile acids, and the production of short-chain fatty acids.

Fiber and cancer

The results of research on the anti-cancer effect of fiber have been published since the 1980s, but they are not always consistent with each other.

Studies conducted in the USA, Finland and Sweden did not provide conclusive evidence of the anti-cancer effect of fiber. Others confirm its anti-cancer properties.

The European Prospective Investigation on Cancer and Nutrition (EPIC), coordinated by the International Agency for Research on Cancer, tested over half a million people to assess the relationship between diet and cancer.

In the published report, researchers found that compared to people who consumed 15 g of fiber per day, people who provided 35 g of this nutrient reduced the risk of cancer by 40 percent.

Other scientists have published a paper comparing the effects of fiber consumption on the risk of stomach cancer.

The results of 21 articles published up to 2012 were analyzed. It was found that an increase in dietary fiber consumption by 10 g / day lowers the risk of developing gastrointestinal cancer by up to 44%, which confirms the results of previous studies.

Dietary fiber may also reduce the risk of breast cancer. Scientists compared the results of 10 scientific studies in which over 700,000 people took part. women, of which 16,848 had breast cancer diagnosed.

The authors found that among women who consumed higher amounts of dietary fiber, the incidence rate was lower by 11%. and an increase in fiber consumption by 10 g / day reduces the incidence by 7%.

The anti-cancer effect of fiber may result fromits: beneficial effects on the functioning of the colon by stimulating the production of new cells, preventing epithelial atrophy (atrophy), improving the passage of food through the intestines, as well as the ability to ferment, resulting in the formation of significant amounts of short-chain fatty acids.

In breast cancer, the anti-cancer effect of fiber is attributed to its ability to remove excess estrogen in the faeces.

Fiber and diabetes

Increasing the content of dietary fiber in meals contributes to smaller fluctuations in blood glucose levels, allows you to control blood sugar levels, and thus - to prevent type 2 diabetes.

The American Diabetes Association recommends an intake of at least 14 g / 1000 kcal / day, or 25 to 30 g / day.

It can also help people who are already struggling with diabetes, as demonstrated by scientists from the Medical University of South Carolina, USA .²

The aim of their study was to answer the question whether the consumption of dietary fiber may affect the level of glycosylated hemoglobin HbA1c and fasting glucose in patients with type 2 diabetes. glycosylated hemoglobin was performed on a group of 324 patients.

The results of the study showed that in patients who were recommended to consume more dietary fiber in the daily diet by an average of 18 g / day, there was a significantly greater decrease in fasting glucose by 0.85mmol / L, i.e. 15.32 mg / day dl compared to patients taking placebo.

Similarly, in this group of patients, scientists observed by 0.26 percent. greater decrease in the level of glycated hemoglobin HbA1c than in the placebo group.

The authors emphasize that although the decrease in glycated hemoglobin is not impressive, the long-term use of dietary fiber may be of greater importance and constitute an element complementing the pharmacotherapy of type 2 diabetes.

How much dietary fiber per day? Side effects, contraindications

In 2010, EFSA published the Dietary Intake (AI) value of dietary fiber for adults at 25 g / day, and for children from 10 to 21 g / day depending on age.

On the other hand, specialists from IŻiŻ in the 2013 amendment to the standards for the Polish population already provide the recommended standard of dietary fiber consumption in the amount of 30-35 g / day for adults.

According to the World He alth Organization (WHO), the daily intake of fiber in adults should be 20-40 g. Do not exceed these doses. Eating too much fiber in your diet canlead to:

  • of quantitative and qualitative deficiencies of other nutrients, and thus a decrease in the caloric content of the food consumed. It is especially dangerous for people with normal and low body weight, as it may lead to symptoms of malnutrition
  • deficiencies of calcium, iron and zinc. This is due to the ability of fiber to bind these minerals in the intestine and excrete them in the faeces, making it impossible for them to be absorbed into the bloodstream. The same goes for fat-soluble vitamins
  • flatulence, and constipation may appear with inadequate fluid intake

Diseases in which too much fiber consumption is inappropriate, such as gastritis or gastric ulcer, pancreatitis, inflammation of the bile ducts, intestines or anemia.

We recommend

Author: Time S.A

A balanced diet is the key to he alth and better well-being. Use JeszCoLubisz, the innovative online dietary system of the He alth Guide. Choose from thousands of recipes for he althy and tasty dishes using the benefits of nature. Enjoy an individually selected menu, constant contact with a dietitian and many other functionalities today!

Find out more

fiber for constipation

Fiber in the presence of water increases its volume, and thus also the volume of the stool, facilitating its passage through the intestines and excretion outside the body.

In addition, fiber stimulates intestinal peristalsis, which leads to more frequent and regular bowel movements, and consequently to a lack of constipation. However, the effectiveness of fiber in this regard depends on the type of fiber.

Dietary fiber contained in small bran, as well as in more processed products, does not have such an effective effect on intestinal passage as fiber, the source of which is taken from low-processed and whole grain foods.

Don't go overboard with the amount of fiber a day. Remember to drink it with enough water - otherwise you may become constipated.

The effectiveness of fiber in terms of the digestive system also depends on the amount of water you drink. Italian scientists conducted research on the effectiveness of dietary fiber on intestinal peristalsis, which was supported by the consumption of additional amounts of water.

The study group was divided into two control groups that received a standard diet containing 25 g of fiber, with the first drinking 1 liter of water / day and the second drinking 2 liters of water / day for two months.

The amount of dietary fiber consumed in the study group doubled.Based on the research, it was found that the frequency of defecation per week increased, but with additional supplementation with water, much better results were noted.

Dietary fiber is an effective remedy for constipation, but remember to carefully select products containing the best-quality fiber and to have an adequate supply of fluids.

fiber and slimming

Fiber absorbs water, thanks to which the consumed food increases its volume in the stomach, giving a feeling of fullness.

Another function of fiber to help you feel full is to slow stomach emptying and the absorption of nutrients. Thanks to this, the feeling of fullness lasts a long time and stops the urge to eat.

In addition, food rich in dietary fiber in most cases also requires increased chewing, because it is harder.

Thanks to this activity, the feeling of fullness is also felt faster, because the meal is eaten slowly and the bites of food are chewed for longer. In this way, fiber supports weight loss.

What is fiber in? Fiber-rich broducts

The source of fiber is mainly cereal products made of low-mill cereals, such as: high-type flours (e.g. graham type 1850), bread made from them and multigrain flakes, e.g. natural rye flakes (11.6 g / 100g), whole grain rye bread (6.1 g / 100 g).

Another very good source of fiber are fruits and vegetables - the fruits rich in fiber are especially currants (7.9 g / 100g) and raspberries (6.5 g / 100g). They should be consumed in the amount of 5 servings / day.

It is recommended to consume seeds and plant seeds between meals instead of sweets, e.g. sunflower seeds (8.6 g fiber / 100 g), pumpkin seeds (6 g fiber / 100 g) and dried fruits such as figs ( 9.8 g of fiber / 100 g) or apricots (10.3 g of fiber / 100 g) and plums (10 g / 100 g).

It is worth paying attention to flaxseed, which is a very good source of fiber at the level of 27.3 g / 100 g of the product.

Source of soluble fiberSource of insoluble fiber
  • oat bran
  • dried beans
  • brown rice
  • barley
  • citrus
  • strawberries
  • apples
  • potatoes
  • wheat bran
  • wholemeal flour
  • beans and peas
  • corn
  • plant seeds
  • whole grains
  • cruciferous vegetables
  • root vegetables
  • nuts

Foods rich in fiber

See gallery 5photosImportant
  • If you've avoided high-fiber foods so far, add them to your diet gradually. It should take several weeks to reach the recommended dose. Sudden increase in fiber can cause gas, gas and loose stools
  • do not exceed the recommended fiber limit, so as not to impair the absorption of vitamins and minerals
  • always drink fiber with plenty of water
  • for 2 hours after taking the preparation, it is better not to take other medications, because fiber may delay their absorption
About the authorMonika Majewska A journalist specializing in he alth issues, especially in the areas of medicine, he alth protection and he althy eating. Author of news, guides, interviews with experts and reports. Participant of the largest Polish National Medical Conference "Polish woman in Europe", organized by the "Journalists for He alth" Association, as well as specialist workshops and seminars for journalists organized by the Association.

Category: