There is a clear link between living to 100 and inheriting a hyperactive version of an enzyme that prevents cells from ageing, researchers say.

Scientists from the Albert Einstein College of Medicine in the US say centenarian Ashkenazi Jews have this mutant gene.

They found that 86 very old people and their children had higher levels of telomerase which protects the DNA. Telomeres are relatively short sections of specialized DNA that sit at the ends of all our chromosomes. They have been compared to the plastic tips at the ends of shoelaces that prevent the laces from unravelling. Each time a cell divides, its telomeres shorten and the cell becomes more susceptible to dying. Telomerase can repair the telomeres, preventing them from shrinking.

The team at Einstein found that the centenarians and their offspring had higher levels of telomerase and significantly longer telomeres than the unrelated people in the control group and that the trait was strongly heritable.

To read the full article on the BBC health news pages, click here