Living With Diabetes

The Role of Glucose,
the Pancreas, and Sugar

The Role of Glucose

Glucose fuels the body's trillions of cells. To enter the cells, however, it needs a "key"—insulin, a chemical released by the pancreas. With Type 1 diabetes, insulin is simply not available. With Type 2, the body makes insulin but usually not enough.* Moreover, the cells are reluctant to let insulin in—a condition called insulin resistance. With both forms of diabetes, the result is the same: hungry cells and dangerous levels of sugar in the blood.

In Type 1 diabetes, a person's immune system attacks the insulin-producing beta cells in the pancreas. Hence, Type 1 diabetes is an autoimmune disease and is sometimes called immune-mediated diabetes. Factors that can trigger an immune reaction include viruses, toxic chemicals, and certain drugs. Genetic makeup may also be implicated, for Type 1 diabetes often runs in families, and it is most common among Caucasians.

With Type 2 diabetes, the genetic factor is even stronger but with a greater occurrence among non-Caucasians. Australian Aborigines and Native Americans are among the most affected, the latter having the highest rate of Type 2 diabetes in the world. Researchers are studying the relationship between genetics and obesity, as well as the way excess fat seems to promote insulin resistance in genetically susceptible people.^# Unlike Type 1, Type 2 diabetes occurs mainly in those who are over 40 years of age.

The Role of the Pancreas

About the size of a banana, the pancreas lies just behind the stomach. According to the book The Unofficial Guide to Living With Diabetes, "the healthy pancreas performs a continuous and exquisite balancing act, managing to sustain smooth, stable blood-sugar levels by releasing just the right amount of insulin as glucose levels wax and wane throughout the day." Beta cells within the pancreas are the source of the hormone insulin.

When beta cells fail to produce enough insulin, glucose builds up in the blood, causing hyperglycemia. The opposite—low blood sugar—is called hypoglycemia. In concert with the pancreas, the liver helps manage blood-sugar levels by storing excess glucose in a form called glycogen. When commanded by the pancreas, the liver converts glycogen back into glucose for use by the body.

The Role of Sugar

It is a common misconception that eating a lot of sugar causes diabetes. Medical evidence shows that getting fat—regardless of sugar intake—increases the risk among genetically susceptible individuals. Still, eating too much sugar is unhealthy, since it provides poor nutrition and contributes to obesity.

Another misconception is that people with diabetes have an abnormal craving for sugar. In reality, though, they have the same desire for sweets as most others. When it is not controlled, diabetes can lead to hunger—but not necessarily for sugar. People with diabetes can eat sweets, but they must factor their sugar intake into their overall diet plan.

Recent studies have shown that a diet high in fructose—sugar derived from fruits and vegetables—can contribute to insulin resistance and even diabetes in animals, regardless of their weight.

* About 90 percent of those with diabetes have Type 2. Previously, this was referred to as "non-insulin dependent" or "adult onset" diabetes. However, these terms are imprecise, for up to 40 percent of those with Type 2 diabetes require insulin. Furthermore, an alarming number of young people—some not even in their teens—are being diagnosed with Type 2 diabetes.

^# A person is generally considered to be obese when 20 percent or more above his or her ideal body weight.