Fiber is found only in vegetables. Improving intestinal transit and regulating cholesterol are some of its benefits, but it has many more.
Fiber is not absorbed and does not provide us with calories, but as it passes through the intestines it leaves behind a series of benefits that make it essential for good health.
The best known and most sought after is perhaps the one to relieve constipation and some types of fiber that are excellent for it. Another fundamental is to feed the good bacteria in the intestine, which improves the state of our microbiota or intestinal flora.
However, there are different types of fibers and each one has specific effects on the body: they can boost the immune system, help reduce cholesterol, prevent the formation of gallstones.
The more varied vegetables we include in the diet, the greater variety of fibers we will ingest and the more we can benefit from its effects.
To improve constipation and thus prevent diseases derived from inadequate transit, you need to take 25 grams of fiber daily.
Pectin
It is found in the skin and pulp of certain fruits and vegetables. It is a soluble fiber that the intestinal microorganisms ferment, which increases the volume of the fecal mass.
It exerts a purifying function and helps regulate glycemic levels thanks to its slowing action on the absorption of sugars and fats. It also eliminates the juices secreted by the liver and gallbladder during digestion, thereby preventing an increase in cholesterol.
The apple is a good source of pectin. It is also contained in grapes, citrus fruits, quince and carrots.
Lignin
It is the fiber responsible for the stiffness of the stems of lettuce, chard and other vegetables, although it is also found in alfalfa, rice and legumes. After polysaccharides, lignin is the most abundant organic molecule in the plant world.
It is an insoluble fiber, it is not absorbed and it is scarcely attacked by the micro flora of the colon, which prevents fermentation and gases.
It can bind to bile acids and cholesterol, which reduces the absorption of these components in the small intestine and, therefore, their passage into the bloodstream.
Mucilage
Mucilage, a soluble fiber that swells with water and forms colloidal solutions or gels, are abundant in algae, figs, whole grains, flax, okra and phylum . In plants they act as water reservoirs, which prevents dehydration and favors germination.
The richest algae are the rhodofíceas (from which agar-agar and carrageenan are obtained) and the pheophytes (which produce algin).
This fiber is combined with bile acids and has cholesterol-lowering action, as well as anti-inflammatory and emollient properties of both the digestive and respiratory mucosa.
Beta glucans
In oats, beta-glucans are concentrated in the bran, one of its most important sources. They are soluble dietary fiber and form a very diverse group of molecules of different size, solubility, and viscosity.
They have the ability to regulate the immune system without overstimulating it and to normalize LDL or bad cholesterol. They have also been shown to have great potential as adjuvants in the treatment of cancer. Other sources of beta-glucans are barley, quinoa, brewer”s yeast, mushrooms, and algae.
Rubbers
The carob beans and the cream that is made with them to spread provide gums. These soluble fibers are also found in plants such as those from which guar gum or gum arabic is obtained. In the plant kingdom, gums act as protection.
Their viscosity is the key to their therapeutic efficacy, as they prolong the intestinal absorption of fats, carbohydrates, and sodium, which is useful in reducing postprandial hyperglycemia, body weight, and cholesterol levels. It also increases the volume of stool, softens it and promotes excretion.
Cellulose
This water-insoluble fiber is probably the best known and is part of the walls of plant cells. It is found mainly in the bran of cereals and vegetables. Its best sources are, therefore, whole grains.
Vegetables include green beans, spinach, artichoke, and peas.
Cellulose retains little water in the body and its main effect is to clean, like a brush, the walls of the intestine. It helps to loosen the waste adhering to the mucosa, facilitates bowel movements and reduces the transit time of the stool.
Fructans
The fructan or fructooligos accharides (FOS) is a soluble fiber that reaches intact the colon and there acts in three ways: keeps moisture in the stool and lowers the pH of the colon, stimulates growth of microbiota or intestinal flora beneficial and provides energy to the epithelial cells of the intestinal mucosa, which helps to maintain optimal intestinal permeability.
Inulin stands out, which is abundant in artichokes. This fructan also strengthens the immune system and improves the absorption of minerals.
Chicory root, onion, and asparagus are other sources of fructans.