Why things may start looking brighter if you live to 105

Living until the age of 100 may seem like a worthy goal, but a new 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.

Curious new research has found that death rates, which increase exponentially with age, begin to decelerate after 80 years old 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 US studied the survival rates of nearly 4,000 people over 105 between 2009 and 2015.

In Britain the lowest chance of death occurs between the ages of 4 and 15 when men have one in a 8333 chance of dying annually, and women one in 10417, according to figures from the Office for National Statistics (ONS).

Between 35 and 44 that risk has risen for men to one in 663 and women to one in 1106, and by the age of 75 it is one in 15 for men and one in 21 for women.

However the new 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 are above 105, the risk levels off at around 47 per cent risk of death - roughly a one in two chance and stays at that level, or even dips slightly, up to 110 and beyond.

Lead author Elisabetta Barbi, of Sapienza University of Rome, said: “The increasing number of exceptionally long-lived people and the fact that their mortality beyond 105 is see 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, with a baby born today expected to live until 81, compared to just 50 years in 1900. 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.

Co-author Ken Wachter,  Professor of Demography and Statistics, Emeritus University of California,  said by the time people had lived to 105 they had shown the ability to battle most diseases and conditions.

"There has been selection - those initially less frail are the  ones who tend to survive to 105. 

"Processes of selection are likely balancing further debilitation.    This selection likely also involves loads of genetic variants with harmful effects,   whose effects at extreme ages have been kept in check by processes of natural selection."

Latest figures from the ONS show there were 14,910 people aged 100 and over living in Britain in 2016, or two for every 10,000 people, a rise from 14,520 in 2015 and 7,750 in 2002.

Over the past 30 years numbers have more than quadrupled from 3,642 centenarians in 1986.

Most centenarians are women with five female centenarians for every male centenarian in 2016

The ONS found that the oldest people are getting older. Between 2002 and 2016 the proportion of the older over-90s rose in comparison with younger groups.

There were 571,245 people aged 90 and over living in the UK in 2016, the highest number ever in that age category.

The new research was published in the journal Science.