Excessive consumption of fructose has been linked to insulin resistance, obesity and non-alcoholic liver disease. Studies suggest that it leads to added fat in the belly, which is linked to an increased risk for heart disease and diabetes. Fructose also leads to higher cholesterol. Studies suggest that fructose lowers activity in the cortical control areas of the brain.
An excessive amount of glucose in the blood can be fatal. However, this only occurs in diabetic individuals when their pancreas does not release enough insulin into the bloodstream. Most fat gained from excessive intake of glucose is subcutaneous, or under the skin, which is not connected to heart disease or diabetes. Glucose is not linked to insulin resistance or higher cholesterol. Studies suggest that the consumption of glucose significantly raises the level of activity in the brain.