Dietary fiber

Nowadays, more and more health and nutrition professionals suggest adding foods with dietary fiber to our meals. Although it is not a nutrient in the strict sense, since it is not directly involved in basic metabolic processes, dietary fiber has beneficial physiological effects and contributes to the prevention of chronic degenerative diseases.

Dietary fiber: refers to a set of substances present in plant foods that are neither digested nor absorbed in the small intestine, and that undergo partial or complete fermentation in the large intestine.

Components of dietary fiber:

• Cellulose: it is a component of the cell walls of vegetables. It is found in whole wheat flour and in vegetables such as green beans, spinach and artichokes.

• Hemicellulose: consists of a mixture of glucose, galactose and other substances. It is part of the insoluble fiber in vegetables and is found in whole grains and bran.

• Pectic substances: polymers present in the peel of fruits such as apples, and in the pulp of citrus fruits, strawberries and carrots. They are fermented by microorganisms in the intestine and increase fecal volume.

• Resistant starch: found in foods such as potatoes, in which part of the starch is not easily digested. This starch, called "resistant starch", is degraded by the intestinal microflora and works in a similar way to dietary fiber. It is found in tubers and seeds.

• Inulin: is a carbohydrate that is not digestible by digestive enzymes. It is present in onions, garlic, thistle and artichoke.

• Lignin: compound containing phenylpropyl acids and alcohols, forming an insoluble fiber that binds to other substances and facilitates their elimination by the digestive tract. It is present in hard and woody parts of vegetables such as chard and lettuce.

• Gums: soluble fibers composed of uronic acid, xylose, arabinose or mannose, such as guar gum, gum arabic and tragacanth.

• Mucilages: polysaccharides secreted by some plants. Some act as laxatives and are found in acacia and tomato seeds.

Functions of dietary fiber: Helps reduce intestinal transit time, increases the frequency of bowel movements and prevents constipation. It also slows down the absorption of sugars and fats, which reduces caloric intake. Pectins, soluble in water, reduce cholesterol levels, helping in its prevention and treatment. It is believed that fiber traps bile acids and carcinogenic substances in the colon, which decreases the risk of colon cancer. In addition, it increases the feeling of satiety, facilitating weight control and reducing the risks of cardiovascular diseases. It improves the functionality of the gastrointestinal tract and promotes the growth of beneficial intestinal bacteria.