PLoS Genet. 5, e1000467 (2009)

Restricting calories is known to increase life span, but changing the source of those calories can affect organisms in similar ways, reports a team led by Valter Longo at the University of Southern California in Los Angeles.

Longo's team studied long-lived Saccharomyces cerevisiae mutants lacking SCH9 and other genes involved in yeast life extension. The mutants expressed higher levels of genes involved in glycerol synthesis and metabolism. Knocking out glycerol-synthesis genes eliminated life extension in mutants lacking SCH9. And a glycerol diet allowed yeast to live at least twice as long as those fed glucose, and slightly longer than those on calorie-restriction diets. The team concludes that replacing pro-ageing foods such as glucose with glycerol helps to boost cellular protection and lengthen yeast lifespan.