Nutri-Link Ltd

Blood Sugar Basics (Glucose Metabolism)

The term “blood sugar” refers to the level of glucose found in the blood. Glucose is a simple sugar and the body’s primary source of cellular energy. Carbohydrates are the main dietary source of glucose. Rice, potatoes, bread, pasta, cereals, fruit, sweets and even milk are all carbohydrate-rich foods.

Although blood glucose levels generally stay within defined limits throughout the day (a fasting blood glucose level lower than 6mmol/l is normal, but a fasting blood glucose of 7mmol/l or higher may indicate diabetes), fluctuations follow a relatively set pattern. Blood sugar rises immediately after meals and falls within approximately two hours. Levels are typically lowest in the morning or following periods of fasting. The speed at which blood sugar rises and falls and the level to which it will increase are dependent upon both internal (i.e. hormonal regulation) and external (e.g., diet and exercise) variables.

Regulation of Blood Sugar

Blood sugar concentration, also referred to as serum glucose level, is closely and continuously monitored by the pancreas, a gland which plays important roles in both the digestive and endocrine systems. When blood glucose levels fall, the pancreas releases the hormone glucagon, causing the liver to convert stored gycogen into glucose and release it into the bloodstream, raising blood glucose levels and ultimately preventing the development of hypoglycaemia.

Blood sugar can also be increased through the intake of food. When food is digested, it is broken down into basic chemical components. Dietary proteins are metabolised to individual amino acids; fat molecules get broken down into glycerol and fatty acids; and carbohydrates are broken down to simple sugars (e.g., glucose). Consuming foods containing high levels of carbohydrates can significantly impact blood glucose levels.

After a meal, glucose molecules are absorbed into the bloodstream and carried to the cells where they are used for energy. Insulin, a hormone produced by the pancreas, helps glucose enter cells. If the individual takes in more glucose than the body needs at the time, the body stores the extra glucose in the liver and muscles in a form called glycogen. The body can use the stored glucose whenever it is needed for energy between meals. Extra glucose can also be converted to fat and stored in fat cells.

When blood glucose begins to fall, glucagon, another hormone produced by the pancreas, signals the liver to break down glycogen and release glucose, causing blood glucose levels to rise toward a normal level. If the individual has diabetes, this glucagon response to hypoglycemia may be impaired, making it harder for glucose levels to return to the normal range.

And when blood sugar levels rise, insulin is released by the beta cells of the Islets of Langerhans found in the pancreas. This hormone causes the liver to pull excess glucose from the bloodstream and convert it to glycogen for storage.

Related products available at Nutri-Link: