A yeast is a worm is a fly is a person? At least the first three creatures live longer when they sup an extract of red wine, according to new research. The chemical activates related enzymes in all three organisms and might duplicate the life-prolonging effects of extreme dieting. By showing for the first time that the compound works in animals, the results bring human studies a step closer.
Yeast live longer with extra copies of the SIR2 gene. The Sir2 protein belongs to a family of proteins called sirtuins that also appear in humans and other animals, and researchers wonder whether sirtuins also prolong our lives. In a study that thrilled the wine industry, molecular geneticist David Sinclair of Harvard Medical School in Boston and colleagues reported last year that the sirtuin-stimulator resveratrol, a component of red wine, lengthened life in yeast cells (ScienceNOW 25 August 2003). Those results were promising, says Sinclair, "but let's face it, it's only a fungus."
Hoping to extend the findings, the team checked whether resveratrol and several related compounds stretch longevity in flies and nematodes. Resveratrol prolonged worm lifespan by up to 14%. It and a kindred molecule, called fisetin, also bought extra days for fruit flies--boosting their lifespan by up to 29%, the team reports online this week in Nature. And that wasn't because the flies were eating less, they found. However, the compound does appear to extend longevity through the same pathway as calorie restriction. When the researchers slashed rations, the flies lasted no longer if they also slurped resveratrol.
The finding that the molecule can stretch lifespan in more complex creatures than yeast is "crucial" to advancing toward human studies, says molecular geneticist Stewart Frankel of the University of Hartford in Connecticut. Molecular biologist Leonard Guarente of the Massachusetts Institute of Technology says that the study "makes it increasingly likely that Sir2 will be universal in regulating diet and lifespan." Sinclair's group has begun testing the compound in rodents.