Geneticists Discover a Way to Extend Lifespans to 800 Years
There is now a way to extend the lifespan of organisms so that humans could conceivably live to be 800 years old. In an amazing development, scientists at the University of Southern California have announced that they’ve extended the lifespan of yeast bacteria tenfold — and the recipe they used to do it might easily translate into humans. It involves tinkering with two genes, and cutting down your calorie intake. Tests have already started on people in Ecuador.
Longo’s group put baker’s yeast on a calorie-restricted diet and knocked out two genes – RAS2 and SCH9 – 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 says. Normal yeast organisms live about a week.
"I would say 10-fold is pretty significant," says Anna McCormick, chief of the genetics and cell biology branch at the National Institute on Aging (NIA) and Longo’s program officer. The NIA funds such research in the hope of extending healthy life span in humans through the development of drugs that mimic the life-prolonging techniques used by Longo and others, McCormick adds.
Baker’s yeast is one of the most studied and best understood organisms at the molecular and genetic level. Remarkably, in light of its simplicity, yeast has led to the discovery of some of the most important genes and pathways regulating aging and disease in mice and other mammals.
Longo’s group next plans to further investigate life span extension in mice. The group is already studying a human population in Ecuador with mutations analogous to those described in yeast.
"People with two copies of the mutations have very small stature and other defects," Longo says. "We are now identifying the relatives with only one copy of the mutation, who are apparently normal. We hope that they will show a reduced incidence of diseases and an extended life span."
Longo cautions that, as in the Ecuador case, longevity mutations tend to come with severe growth deficits and other health problems. Finding drugs to extend the human life span without side effects will not be easy.