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'Humans could live for hundreds of years'
Scientists say people could live active lives for hundreds of years if humans follow the same biological rules as laboratory worms.

By carefully tweaking genes and hormones, scientists extended the lifespan of the tiny roundworm Caenorhabditis elegans six times. In human terms, the worms stayed healthy and active for 500 years.

The researchers pointed out that the chief mechanism they tampered with - a signalling pathway involving insulin - was common in many species, including mammals.

But many people might find the price of immortality a little high. The worms with the longest lifespans also had their reproductive systems removed....