Opposite fates of fructose in the development of metabolic syndrome.

This short review comments on the recently published work of Ishimoto et al regarding the opposing effects of fructokinase C and A isoforms on fructose-induced metabolic syndrome in mice. The framework for the commentary is the preexisting background of epidemiological and experimental data regarding the association between ingestion of fructose, as present in sweetened beverages, and the development of metabolic syndrome. The work of Ishimoto et al clearly confirms the negative effect of fructose on lipid and glucose metabolism, independently from the amount of energy provided by the ingested sugar. It also confirms the absolute requirement of liver fructose metabolism, driven by fructokinase activity, in order to develop the full spectrum of metabolic syndrome alterations.