Monday, July 16, 2012

Fructose metabolism



Excess fructose consumption has been hypothesized to be a cause of insulin resistance, obesity,[41] elevated LDL cholesterol and triglycerides, leading to metabolic syndrome.[42] In preliminary research, fructose consumption was correlated with obesity.[43][44] A study in mice showed that a high fructose intake may increase adiposity.[45]


One study concluded that fructose "produced significantly higher fasting plasma triacylglycerol values than did the glucose diet in men" and "...if plasma triacylglycerols are a risk factor for cardiovascular disease, then diets high in fructose may be undesirable".[50]


Fructose is a reducing sugar, as are all monosaccharides. The spontaneous chemical reaction of simple sugar molecules binding to proteins is known as glycation. Showing potential cause of skin and bone damage in a rat model of diabetes, investigators suggested "that long-term fructose consumption negatively affects the aging process."[51]


Liver function


While a few other tissues (e.g., sperm cells[59] and some intestinal cells) do use fructose directly, fructose is metabolized primarily in the liver.[60]


Compared with consumption of high glucose beverages, drinking high fructose beverages with meals results in lower circulating insulin and leptin levels, and higher ghrelin levels after the meal.[61] Since leptin and insulin decrease appetite and ghrelin increases appetite, some researchers suspect that eating large amounts of fructose increases the likelihood of weight gain.[62]


Excessive fructose consumption may contribute to the development of non-alcoholic fatty liver disease.[63]




A 2008 study found a substantial risk of incident gout associated with the consumption of fructose or fructose rich foods.[64] Cases of gout have risen in recent years, despite commonly being thought of as a Victorian disease, and it is suspected that the fructose found in soft drinks (e.g., carbonated beverages) and other sweetened drinks is the reason for this.[65][66]