Sucrose: Common table sugar. It is a 50-50 combination of glucose and fructose. Sucrose quickly breaks down in the intestines into glucose and fructose, which head to the liver via the portal vein where they undergo different biological processes.
Glucose: A slightly sweet form of sugar produced by the breakdown of starches and carbohydrates, including sugar, and used to energize cells with the help of insulin. The liver has first rights to all consumed sugar. If the liver has sufficient energy, an enzyme that metabolizes glucose turns off. Unused by the liver, the glucose goes bodywide to energize muscles, organs and the brain. Too much blood glucose can lead to insulin insensitivity, allowing glucose to build up in the blood. The result is metabolic syndrome that can progress to type 2 diabetes.
Fructose: A sugar found naturally in fruits. In this form it is not considered a health risk because levels are low; the fiber in fruit delays the rate of metabolism. It can become a problem, though, when consumed as added sugar. Fructose's first stop also is the liver. A different liver enzyme metabolizes the fructose upon its arrival. Very little fructose gets to the muscles, organs or the brain. Too much fructose can overwhelm the liver, causing the development of fat in the liver, which also can be a factor in high cholesterol and arterial plaque.
High Fructose Corn Syrup: A sugar chemically produced from corn starch. This form of fructose is cheaper than sucrose with the added appeal of providing food texture and also serving as a preservative. For these reasons, it is used in a large variety of processed foods, particularly a type used in soft drinks that is a 55-45 combination of fructose to glucose. Recent studies are showing fructose to be a factor in the development of cardiovascular disease, diabetes, stroke and diseases related to fatty buildups in artery walls.