A high intake of dietary fiber has undeniable health benefits and is associated with a reduction in all-cause mortality.
Dietary fibers (or cellulose) are food components of plant foods that are not digested and absorbed in the upper gastrointestinal tract, but are fermented by the microflora of the human large intestine and stimulate its growth and vital activity.
A meta-analysis has recently been published that shows a significant reduction in the risk of death from all causes due to a higher total intake of dietary fiber (about 40 g per day), compared with a lower intake of fiber.
Comparison of observed patients with high intake of dietary fiber with patients with the lowest intake shows the former to have a lower mortality from all causes and cardiovascular diseases by 15-30%, as well as a lower incidence of death from coronary heart disease, death from stroke, diabetes Type 2 and colorectal cancer.
Those who consume a lot of dietary fiber have a significantly lower risk of developing coronary heart disease, stroke, hypertension, diabetes, obesity, and some gastrointestinal diseases.
Increasing fiber intake lowers blood pressure and serum cholesterol, improves glycemia and insulin sensitivity.
Dietary fiber appears to enhance immune function.
The principle of action of fiber is to change the nature of the contents of the gastrointestinal tract and to change the absorption of nutrients.
But fiber is just one of the components of food, and neglecting other components – be it proteins, fats, vitamins or minerals – is wrong.
While regular consumption of fiber-rich foods provides health benefits, the average intake of dietary fiber is typically less than half of the recommended amount.
Dietary fiber is found in fruits and vegetables, grains and legumes, oats and nuts.
When they enter the digestive tract, they are not destroyed by human digestive enzymes. Low fiber intake is associated with constipation and some bowel diseases, including cancer.
Some fibers can be fermented in the colon by bacteria to produce short chain fatty acids and gases (methane, hydrogen and carbon dioxide).
Often, with an increase in fiber in the diet, quite healthy people experience abdominal discomfort, bloating and flatulence. However, over time, the colon and intestinal bacteria gradually adjust to the increased fiber intake and symptoms improve.
There are different types of dietary fiber. They all work in different ways, and each provides specific health benefits.
Dietary fiber is found only in plant foods. Animal products do not contain them.
Since the components of dietary fiber are found in different proportions in different plant foods and have different properties, it is important to eat a variety of dietary fibers.
You are probably familiar with the terms soluble fiber and insoluble fiber.
- Soluble fiber (or soft fiber) slows down digestion, so your body takes longer to absorb the sugar (glucose) from the foods you eat. This helps prevent spikes in blood sugar levels.
Soluble fiber also binds to fatty acids, removing them from the body and helping to lower bad cholesterol levels.
Soluble fibers include inulin, pectins, gums, dextrans, and mucus.
- Insoluble fibers (or solid fibers) pass through the gastrointestinal tract almost unchanged, retain water well, contribute to the formation of a soft elastic food bolus in the intestines, improve emptying, and prevent constipation.
Some plants contain significant amounts of both soluble and insoluble dietary fiber.
For example, plums (prunes) have a thick skin covering the juicy pulp. The peel is the source of insoluble fiber, while the soluble fiber is found in the pulp. Grapes also contain a fair amount of fiber.
Insoluble dietary fiber contains:
- in whole grains
- in bran
- in legumes
- in seeds and nuts
- in potato skins
- in vegetables (green beans, cauliflower, celery)
- in some fruits (avocados, unripe bananas)
- in the peel of some fruits (plums, grapes, tomatoes)
Soluble fiber is found in varying amounts in all plant-based foods, including:
- in legumes
- in cereals, oats, barley
- in fruits (figs, avocados, plums, berries, bananas, apples, quinces, pears)
- in some vegetables (broccoli, carrots)
- in root crops (Jerusalem artichoke, onion)
- in some seeds (plantain, flax)
- in nuts (most of all in almonds)
I would like to dwell separately on inulin, which belongs to soluble dietary fiber and is used in medicine as a prebiotic.
Prebiotics are non-digestible food components that selectively stimulate the growth and activity of the protective microflora of the human intestine, thereby improving its health.
Inulin belongs to a class of carbohydrates known as fructans.
The main sources of inulin used in the food industry are chicory and Jerusalem artichoke.
Inulin is regarded as a functional food ingredient as it influences physiological and biochemical processes in humans, resulting in improved health and reduced risk of many diseases.
Studies show that its use as a bifidogenic agent stimulates the body's immune system, reduces the level of pathogenic bacteria in the intestine, relieves constipation, reduces the risk of osteoporosis by increasing mineral absorption, especially calcium, and reduces the risk of atherosclerosis by reducing the synthesis of triglycerides and fatty acids in the liver and a decrease in their level in the blood serum.
Inulin modulates the hormonal levels of insulin and glucagon, thereby regulating carbohydrate and lipid metabolism by lowering blood glucose levels.
It is also effective in lowering blood urea and uric acid levels, thereby maintaining nitrogen balance. Inulin also reduces the incidence of colon cancer.
So a high fiber diet:
- normalizes the bowels
- helps maintain gut health
- lowers cholesterol
- helps control blood sugar levels
- helps maintain normal weight
- helps you live longer
Try to eat enough vegetables and fruits every day, if possible fresh and with a peel (the peel contains the maximum amount of dietary fiber).
When cooking vegetables, do not bring them to a too soft state – in such products, the fiber is destroyed. Vegetables should be slightly crunchy.
Include legumes in the menu if there are no contraindications to their consumption. It has been proven that with an increase in the consumption of legumes, the risk of developing pancreatic diseases decreases.
Dried fruits are an excellent source of fiber. You can add dried fruits to cereals instead of sugar, and also use as a sweet for tea or coffee.
Nuts and seeds also contain a lot of fiber, but they are quite high in calories.
Consistently include grain products in your diet: whole grain bread, bran, brown rice, cereals from various cereals.
If you're not getting enough fiber from your diet, dietary supplements can help fill that gap.
The use of dietary fiber in nutrition has been approved by health authorities in many countries, such as the Food and Drug Administration (FDA), the American Heart Association (AHA), the European Commission for Functional Foods (FUFOSE), and the Japanese Ministry of Health.
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