A tiny round worm can live six times longer than normal if certain genes and hormones are tweaked, according to a report in the journal Science.
The tiny round worms can live up to six times longer than usual
The worms - Caenorhabditis elegans - had a metabolic hormone inhibited and their reproductive systems removed.
They went on to stay healthy and active for a human equivalent of 500 years, which is the longest life-span extension ever achieved by scientists.
Researchers say some of these findings may hold true for mammals.
Scientists from the University of California found they could double the lifespan of C. elegans, if they caused a mutation that inhibited insulin signalling.
Insulin, which is a metabolic hormone, regulates the energy molecule glucose within the body.
Researchers discovered that if they inhibited insulin signalling more strongly the worms lived even longer, but they entered a quiescent - or lethargic - state.
Removal of the animals' reproductive systems also had a dramatic effect - the worms' life span increased by 60%. This was not due to infertility, the researchers said, but altered hormone signalling.
Manipulation of the worms' insulin signalling combined with removal of their reproductive systems, produced life spans of six times longer than normal.
"In human terms, these animals would correspond to healthy, active 500-year-olds," said Dr Arantes-Oliveira.
"This indicates that extreme longevity can be un-coupled with quiescence."
She added: "These lifespan extensions, which are the longest mean lifespan extensions ever produced in any organism, are particularly intriguing because the insulin pathway controls longevity in many species, including mammals."