Human Nutrition 3(3+0)

Lesson 13 : Carbohydrates

Carbohydrates and health

The blood of a normal healthy human body contains about 80-100 mg of glucose per 100ml. Insulin, the hormone secreted by the beta cells of pancreas help in regulating the blood glucose level. In persons suffering from the disease, Diabetes mellitus, There is insufficient secretion of insulin and hence the concentration of glucose in the blood may be very high (180-300 mg/100ml of blood), depending on the severity of the disease and this condition is known as hyperglycaemia and glucose is excreted (up to 5 percent) in the urine (Glucosuria).

The two forms of Diabetes mellitus are Insulin dependent and Non-insulin dependent (NIDDM). The symptoms include fasting blood glucose levels above 140 mg/100ml of serum, frequent urination (Polyuria), thirst (Polydypsia), extreme hunger (Polyphagia), rapid weight loss, blurred vision, or a sudden change in vision, easy tiring, drowsiness, and general weakness.

Another carbohydrate disorder is low blood glucose levels or Hypoglycaemia, in which the blood glucose level drops to 40-60 mg per 100 ml of blood. This problem comes in two forms-reactive and fasting. Reactive hypoglycaemia is characterized by irritability, nervousness, headache, sweating and confusion 2-4 hours after a meal, especially one high in simple sugars. It may be caused due to overproduction of insulin by the pancreas in response to the rising blood glucose levels. The fasting hypoglycaemia is usually caused by a cancer in the pancreas which can lead to excessive insulin secretion. The blood glucose falls to low levels after fasting for about a day. This form of hypoglycaemia is, however, very rare.

An intake of 50 to 100 grams of carbohydrate prevents ketosis. If carbohydrate consumption is inadequate, the body can make what it needs to support cell metabolism. However, if inadequate carbohydrate continues for weeks at a time, it results in loss of body protein, ketosis and in turn, a general weakening of the body. If excess carbohydrate is consumed for a long period, it will contribute towards obesity and diabetes.

Simple carbohydrates in the form of sugars as present in candies, sweets, toffees etc when consumed in excess, can be metabolized into acids by bacteria on teeth. The acid can erode the tooth surface leading to dental caries.