Scientists raise hopes for elixir of youth by extending worms' life span six-fold

A tiny worm may hold the secret to the elixir of life after scientists discovered that they could extend its life span to the equivalent of a human living for 500 years.

By manipulating the worm's genes and tweaking its hormones, the scientists were able to make the creature live for up to 140 days - about six times its usual life span.

"In human terms, these animals would correspond to healthy, active 500-year-olds," the scientists, led by Cynthia Kenyon of the University of California, San Francisco, report in the journal Nature.

Normally, nematode worms live for about 20 days although some genetic mutants live for far longer. Extending the worm's longevity more than six-fold was the longest life-span extension ever achieved in such studies, the scientists said.

Some animals, such as turtles and elephants, have exceptionally long life spans yet all organisms alive today have evolved from simpler organisms with lifespans of only a few weeks, showing that longevity can be extended significantly through genetic changes.

"These findings in [the nematode worm] show that remarkable life span extensions can be produced with no apparent loss of health or vitality by perturbing a small number of genes and tissues in an animal," the scientists said.

The findings are "particularly intriguing", they say, because the study involved the suppression of a growth factor in the body of the worm that is also found in mammals, including humans. However, the results were achieved by the removal of the reproductive system, a sacrifice that few people would be prepared to tolerate.