An apparent key to living till 100 years in the form of an inherited cellular repair mechanism that thwarts aging and perhaps helps prevent disease has been discovered by scientists.
Researches at the Albert Einstein College of Medicine at Yeshiva University have said that the finding could lead to anti-aging drugs.
The study involves telomeres, the ends of chromosomes that have been likened to the plastic tips that prevent shoelaces from unraveling.
Telomeres were already known to play a key role in aging.
The new study, which focused on Ashkenazi Jews, found that those who lived the longest had inherited a hyperactive version of an enzyme called telomerase that rebuilds telomeres.
In effect, centenarians tend to have a top-notch body mechanic at work all through the day, which repairs the hardware that runs the body, versus a normal person whose body's cellular control centre is left to wear out with time.
"Humans of exceptional longevity are better able to maintain the length of their telomeres. And we found that they owe their longevity, at least in part, to advantageous variants of genes involved in telomere maintenance," Live Science quoted Yousin Suh as saying.
In the new study, researchers studied Ashkenazi Jews, a homogeneous population whose genetics are well studied.
Three groups were part of the research: A very old (average age 97) but healthy group of 86 people; 175 of their offspring; and a control group of 93 offspring of parents who lived a normal lifespan.
"Our research was meant to answer two questions. Do people who live long lives tend to have long telomeres? And if so, could variations in their genes that code for telomerase account for their long telomeres?" explained Gil Atzmon in a statement.
The scientists concluded "Yes" on both accounts.
The old crowd had "inherited mutant genes that make their telomerase-making system extra active and able to maintain telomere length more effectively. For the most part, these people were spared age-related diseases such as cardiovascular disease and diabetes, which cause most deaths among elderly people," wrote the researchers.
"Our findings suggest that telomere length and variants of telomerase genes combine to help people live very long lives, perhaps by protecting them from the diseases of old age. We're now trying to understand the mechanism by which these genetic variants of telomerase maintain telomere length in centenarians.
Ultimately, it may be possible to develop drugs that mimic the telomerase that our centenarians have been blessed with," said Suh.
The study has been published in the Proceedings of the National Academy of Sciences.