US lead scientist Dr Pankaj Kapahi, from the Buck Institute of Age Research, said that the two mutations set off a positive feedback loop in specific tissues that amplified lifespan, asserting that the worms lived to the human equivalent of 400-500 years.
According to Kapahi, while living for hundreds of years would be difficult, the study has raised the prospect of anti-ageing treatments based on genetic interactions.
The new study involves blocking key molecules affecting the insulin action and a nutrient signalling pathway called Target of Rapamycin (TOR).
Single mutations in the TOR pathway were known to up the lifespan of C. elegans by 30 per cent, while insulin-signalling mutations could double the amount of time they lived; adding the two together was expected to extend longevity by 130 per cent - but it turned out to be much higher.
The new research has been published in the journal Cell Reports.