Living until the age of 100 may seem like a worthy goal, but a study suggests that centenarians should really be aiming to survive past 105, for that's when their risk of death stops rising and even begins to decline.
Research has found that death rates, which increase exponentially with age, begin to decelerate after 80 years of age and then approach a plateau after 105, before starting to dip slightly. It means that people who make it past 105 appear to have slightly less chance of dying than someone slightly younger.
An international team of researchers from Italy, Germany, Denmark and the United States studied the survival rates of nearly 4000 people over 105 between 2009 and 2015.
The research found that counter-intuitively, as people get very old their chance of dying starts to tail off and may even start to reverse, which may indicate that human longevity is increasing overall.
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For people who live beyond 105, the risk levels off at a 60 per cent annual risk of death — roughly a two in three chance — but does not get any worse and may even fall back to below 50 per cent for some people.
Elisabetta Barbi, of Sapienza University of Rome, the report's lead author, said:
"The increasing number of exceptionally long-lived people and the fact that their mortality beyond 105 is seen to be declining across cohorts strongly suggests that longevity is contributing to increase over time and that a limit, if any, has not yet been reached.
"Our results contribute to a recently rekindled debate about the existence of a fixed maximum lifespan for humans, underwriting doubt that any limit is as yet in view."
Since the 19th century average life expectancy has risen almost continuously.
But recent research by Albert Einstein College of Medicine suggested that imperfections in the copying of genes will always mean there is finite limit to human life, and claimed 125 is the upper limit of human lifespan.
The longest human lifespan to date is that of Jeanne Calment of France (1875-1997), who lived to the age of 122 years, 164 days. She died in 1997 in Arles, France.
The new research was published in the journal Science.
- Telegraph Group Ltd