ugar intake has increased considerably over the last century in Western nations. Increasingly the overconsumption of sugar is considered one of the major causative factors in the development of lifestyle diseases such as obesity, metabolic syndrome, diabetes and cardiovascular disease. Sugar is damaging to health because it contains a molecule of fructose, high intakes of which cause insulin resistance, leptin resistance, abdominal obesity and metabolic syndrome. Fructose is particularly damaging when consumed in high amounts because it overloads the liver and this increases de novo lipogenesis, which causes the deposition of lipids in the skeletal muscle and liver. These lipids interfere with the insulin cascade and decrease the sensitivity of cells to the rise in insulin that occurs following glucose consumption. High intakes of soft drinks containing both fructose or high fructose corn syrup may be a primary cause of obesity.
Glucose and fructose can increase cardiac sympathetic activity following ingestions and this increases the heart rate. In isolation, this could cause an elevation in blood pressure due to increased resistance to the flow of blood leaving the heart. However, consumption of glucose does not cause an increase in blood pressure because insulin causes vasodilation in the skeletal muscles, and so the increase in sympathetic nervous system activity in counterbalanced by a reduction in the resistance to flow. Because fructose does not cause a substantial insulin release, consumption of fructose increases blood pressure. Data shows that consumption of a 500 mL of soft drink can elevate blood pressure for 2 hours postprandially1. Because most individuals spend the majority of their time in the postprandial state, regular consumption of sugary drinks could lead to long-term elevations in blood pressure.
