Fructose is the predominant sugar in fruit – an apple, for instance, is roughly 6% fructose, 4% sucrose and 1% glucose by weight – was considered healthy because it did not elevate blood sugar and had a low glycemic index.   Although fructose enters the blood stream slowly and has little effect on bloodsugar, it can become problematic in large doses.  It is shuttled to liver where it is metabolized into triglycerides.  Table sugar (sucrose) is composed of glucose and fructose.

High fructose corn syrup (HFCS-55) is 55% fructose and 45% glucose.  It was introduced in 1978 and by 1985 half of all sugar consumed in the US was from corn-based sweeteners; and 2/3 of that was HFCS.  HFCS causes a huge increase in triglycerides by the liver and an increased storage of fat; called fructose-induced lipogenesis.  Fructose increases blood pressure, increases oxidation of LDL and produces ten times more cross-linking of proteins thereby increaseing AGE’s (advanced glycation end products causing cell damage and chronic inflammation) than glucose.

High fructose corn syrup results in the worst of both worlds:
  • glucose increases insulin –  leading to insulin resistance, high triglycerides, low HDL and high LDL (metabolic syndrome)
  • fructose increases triglycerides – a significant risk factor for cardiovascular disease

The Third National Health and Nutrition Examinastion Survey of Fructose Consumption by US Adults and Children in 2008 estimated that 10% of daily calories consumed by Americans are from fructose; a dramatic increae over the last 30 years.

In the Journal of Hepatology, June 2008, researchers analyzed the parallel increase in the incidence of non-alcoholic fatty liver disease (NAFLD) with increases in obesity, diabetes and fructose consumption.  They concluded that “The pathogenic mechanism underlying the development of NAFLD may be associated with excessive dietary fructose consumption.”
Bottom Line:  avoid any food products containing high fructose corn syrup!