Fructose is a sugar similar to glucose. Fructose is the sweetest sugar. In fact, it is sweeter than the table sugar. It is this property which has made fructose an essential ingredient in several processed foods and beverages. Fructose is used in the form of high-fructose syrup. The widespread use of fructose has raised health concerns.
The increased consumption of fructose can lead to obesity. Although glucose and fructose are similar in several respects, the brain reacts differently to these sugars. The region affected is hypothalamus which contains the satiety center. It has been seen that glucose has the ability to decrease feeding while fructose has the opposite effect. It promotes feeding. Thus, increased fructose intake can lead to obesity, insulin resistance and type 2 diabetes. Fructose can also cause an increased rise in triglyceride levels after a meal.
It is well known that the brain is the seat of memory. Studies have shown that eating more fructose can cause memory impairment. Increase in triglycerides which follows fructose can interfere with the insulin signalling pathway in the brain. This regulatory pathway is concerned with the survival of the brain and also its plasticity. This plasticity represents the ability of the brain to change with new experiences or in other words, memory.
Metabolic syndrome is a condition comprising obesity, hypertension, decreased glucose tolerance and dyslipidemia. It has already been stated that increased fructose intake can lead to obesity and increased triglyceride levels. Fructose at an increased level can also cause hypertension which in turn increases the risk for cardiovascular diseases and kidney diseases. Fructose is also capable of increasing the LDL cholesterol levels. Thus a combination of obesity, insulin resistance, altered lipid levels and hypertension can lead to metabolic syndrome.