A UCLA team, led by Professor Valter Longo, said the yeast was created through a combination of dietary and genetic changes.

Longo said the study is important because it brings science closer to controlling the survival and health of the cell, the basic unit of all living systems.

Scientists and students from USC and the Roswell Park Cancer Institute in Buffalo, N.Y., put the baker's yeast on a calorie-restricted diet, and then disabled two genes that promote aging in yeast and cancer in humans.

"We got a 10-fold life span extension that is, I think, the longest one that has ever been achieved in any organism," Longo said, noting normal yeast organisms live about a week.

The study is to appear in the Jan. 25 issue of the journal PLoS Genetics. A companion study showing the same genetic changes in yeast reverse the course of an accelerated aging syndrome appeared in the Jan. 14 issue of the Journal of Cell Biology.