Humans could stay eternally young, if we believe scientists who suggest genetic process that drive ageing may be switched off.
The American study by researchers at Stanford University Medical Centre contradicts the commonly held theory and gives hope that science eventually may find a way to stop or reverse the ageing process.
"Everyone has assumed we age by rust. But then how do you explain animals that don't age?" senior author Stuart Kim, a professor of developmental biology and of genetics, said in a Stanford University news release.
Kim cited tortoises that lay eggs at 100 and whales that live to 200 years.Those species use the same building blocks for their DNA, proteins and fats as humans, mice and nematode worms.
But the chemistry of the wear-and-tear process, including damage from free radicals, should be the same in all cells, which makes it hard to explain why species have dramatically different life spans, the study reported by Live Science online said on Friday.
Professor Kim and colleagues studied the nematode worm, one of the most primitive living creatures, and found differences between young and old worms that did not match the conventional picture of ageing.
Instead, the results showed that key genetic mechanisms designed for youth had drifted off track in older animals, the report said.
The same process may not happen in humans, Kim said, but the finding should start scientists on a mission to find whether this ageing mechanism is also in people.