March 4, 2009

Fructose linked to insulin resistance

A U.S. study in mice sheds light on the insulin resistance that can come from diets loaded with high-fructose corn syrup, researchers said.

The study, published in the journal Cell Metabolism, showed that mice on a high-fructose diet were protected from insulin resistance when a gene known as transcriptional coactivator PPARg coactivator-1b -- PGC-1b -- was knocked down in the animals' liver and fat tissue. PGC-1b coactivates a number of transcription factors that control the activity of other genes, including one responsible for building fat in the liver.

There has been a remarkable increase in consumption of high-fructose corn syrup, Gerald Shulman of Yale University School of Medicine said in a statement. Fructose is much more readily metabolized to fat in the liver than glucose is and in the process can lead to nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease in turn leads to hepatic insulin resistance and type 2 diabetes, Shulman said.

Metabolic syndrome and type 2 diabetes have both reached epidemic proportions worldwide with the global adoption of the Westernized diet along with increased consumption of fructose, the researchers said.

The study has revealed the transcriptional coactivator PGC-1b as a missing link between fructose intake and metabolic disorders, Carlos Hernandez and Jiandie Lin of the University of Michigan Medical Center, Ann Arbor, wrote in an accompanying commentary.