Fiber isn’t homogeneous substance. It is made up of plant polysaccharides: pectins, cellulose, hemicellulose, resistant starch (it doesn’t exist natural, only during cereals production) and lignins, gums, wax, agar, mucous. Fiber can’t be digested by human enzymes.
Most of people eat only around 15 grams of fiber, but we need minimum 27 to 40 grams per day, according to WHO recommendations.
To achieve effect fiber needs water.
Fiber insoluble in water (cellulose, hemicellulose and lignins) has important influence on our digestive system.
Fiber insoluble in water:
1) stimulates chewing process, production of saliva that protects teeth,
2) binds water in intestine,
3) binds excessive amounts of hydrochloric acid in stomach,
4) stimulates production of gastrin,
5) increases volume of gastric contents by binding water in small intestine,
increases production of gastric juices,
6) improves peristaltis by mechanical stimulation of intestines,
7) prevents from constipation,
8 ) improves defecation,
9) gives satiety,
10) decreases the energy value of diet.
11) prevents from colon cancer!
Fiber prevents from colon cancer, because increases mass of feces and improves peristalsis. So faster peristalsis – shorter time spent by faeces in intestine – shorter contact carcinogens substances with mucous of large intestine.
The best in increasing of mass faeces are cereal products, especially brans. 100 grams of brans bind 450 g of water. 100 grams of potatoes bind 40 g of water.
Fiber soluble in water:
Fiber soluble in water (pectins, gums, mucous) is found in dry seeds of leguminous plants, vegetables and fruits.
1) degraded by bacteria in intestine,
2) swells in small intestine,
3) binds toxic substances and prevents from absorption them by wall of intestine to blood,
4) decreases cholesterol concentration,
5) binds bile acids,
6) increases excretion of fat with feces,
7) delays absorption of triglycerides,
8 ) delays absorption of glucose.
Fiber prevents from following disorders:
– heart attack,
– colon cancer,
– diabetes type II,
– overweight, obese,
Diet too rich in fiber (above 50 grams per day) can cause: diarrhea and irritations of intestine. Fiber decreases absorption of iron, calcium and zinc, so if you try diet rich in fiber, you should supplement these minerals.
Fiber isn’t recommended in following disorders:
– stomach ulcers,
– inflammations of digestive system: stomach, pancreas, bile ducts and intestines.