May 12, 2009

Anti-aging effects studied in yeast

University of Southern California scientists say they have discovered glucose to glycerol conversion in long-lived yeast provides anti-aging effects.

Researchers said they discovered yeast cells maintained on a glycerol diet live twice as long as normal -- as long as yeast cells on a severe caloric-restriction diet -- and are more resistant to cell damage.

The scientists said their study is the first to propose that dietary substitution can replace dietary restriction in a living species.

If you add glycerol, or restrict caloric intake, you obtain the same effect, said senior author Valter Longo. It's as good as calorie restriction, yet cells can take it up and utilize it to generate energy or for the synthesis of cellular components.

Longo and colleagues Min Wei and Paola Fabrizio introduced a glycerol diet after discovering that genetically engineered long-lived yeast cells that survive up to 5-fold longer than normal have increased levels of the genes that produce glycerol.

When the researchers blocked the genes producing glycerol, the cells lost most of their life span advantage.

However, Longo and colleagues suggest the glucose to glycerol switch represents only a component of the protective systems required for the extended survival.

The researchers said their findings indicate glycerol biosynthesis is an important process in the metabolic switch that allows the yeast to activate its protective systems and live longer.

The research appears in the journal PLoS Genetics.