The monosaccharides all have chemical structures of rings made of C, H, and O. Glucose has 6 carbons, 12 hydrogens and 6 oxygens in the form of a ring. It’s found in fruits and vegetables. Fructose is another monosaccharide, it has 5 carbons, 12 hydrogens, and 6 oxygens. Fructose is found in fruits and vegetables. Galactose has the same chemical make-up as glucose but in another form. It is usually found with glucose in lactose.
The polysaccharides are made up of the three monosaccharides. There are many and some cannot be digested by humans, such as cellulose (the most common on earth) and fructooligosaccharide (a component of certain flavenoids). There are disaccharides made up of two monosaccharides, and long chains with or without branches made up of monosaccharides, these are starches and fibers.
The disaccharides are maltose, sucrose, and lactose. Maltose is made of two glucose units. It is found in malt beverages and candies like whoppers. Sucrose is made of glucose and fructose. It makes up the majority of added sugars and table sugars. Lactose is glucose and galactose. It’s found in milk across species.
Carbohydrates begin digestion in the mouth. There are enzymes released by the salivary glands that break down complicated carbs into the simple sugars. Some absorption happens here, but most take place later on in the GI tract. The small intestines contain enzymes that continue the digestion and absorption process. The large intestine also contributes to the work with some bacteria that help to ferment larger fibers in order to get nutrition from them in the form of glucose.
Blood glucose levels fall between meals. In order to compensate for this, the body uses signal hormones in order to release more glucose if it is not being satiated by meals. When blood glucose levels rise as a result of a meal, the signals are reversed.
In the case of a high blood glucose situation, the liver releases insulin. The insulin ‘tells’ cells to absorb excess glucose from the blood.
In the case of low blood glucose levels, the insulin retreats and glucagon is released from the pancreas. This hormone signals to the liver to break down the stored glycogen into its glucose parts to make up for the lower glucose levels in the blood.
Sugars contribute to health problems in two ways. They can cause bacteria in the mouth to promote cavities in the teeth and encourage obesity.
When sugars are eaten, bacteria eat away at the substance in the mouth and produce an acidic waste product that eats away at tooth enamel. This created cavities in the teeth.
Carbohydrates are energy-yielding nutrients, meaning that they contribute kCalories to your diet. If these calories are not burned by activities other than the daily processes in the body then they are stored. These sugars are stored in the body as fat, and when this happens ‘too’ often, the fat storage exceeds healthy parameters leading to a surplus of health-related issues.
Lactose intolerance is most common in people of Asian, Native American and African descent. These people do not have enough or properly working lactase enzymes in their GI tract. The enzyme lactase breaks down lactose in order to digest it. Although young children have the most active and efficient lactase, peoples with Nordic or Northern European descent only suffer from lactose intolerance 10% of the time while the before mentioned peoples suffer 70%-80% of the time. Lactose intolerance can result in diahrea, constipation, and abdominal discomfort.
Starch is the most common polysaccharide in the human diet. It makes up plentiful foods and is found in virtually all grains and beans and most vegetables. It’s used in the body to store energy because of its structure as a long chain of glucose. It is recommended that one eats between 100 and 300 grams of starch a day.
At least 14 grams of fiber is recommended. Fiber is the non-digestible forms of carbohydrates. These help the GI tract move the rest of the foods through the bowels. Fiber also contributes some nutrients (very little) through the fermentation process that occurs by bacteria in the colon. Some research suggests that a diet high in fiber can decrease the likelihood of heart disease.