Researchers studying a group of people with an average age of 97 found they had all inherited a gene that appears to prevent cells ageing.
They found that the 86 people studied and their children had higher levels of an enzyme called telomerase which is known to protect the body’s DNA from degrading.
The team from Albert Einstein College of Medicine in New York, who studied an American Ashkenazi Jewish community, said that the finding could lead to anti-aging drugs.
Telomerase is known to protect telomeres which stop the string of DNA unravelling much like the plastic tips at the ends of shoelaces stop fraying.
Each time a cell divides, its telomeres shortens and the cell becomes more susceptible to dying.
By boosting telomerase, scientists think they could eventually stop the cells dying and so protect against old age.
The research was published in the Proceedings of the National Academy of Sciences journal.