Live long and prosper is a popular well-wish, but human existence seems to have hit a glass ceiling as medical discoveries that help people live for longer are no longer delivering.
The general acceptance for decades was people were living longer and would continue to do so.
Historical data supported the theory, showing that from Victorian times to the start of the 21st century, predicted lifespans for men and women improved by adding an extra year every four years or so.
But something happened around 2011 that has left a malaise humans have yet to recover from.
For some reason, scientists realised longevity was standing still, which begs the question how long can a human live?
Lack of medical advances
The oldest documented person was Jeanne Calmont, a French woman who died at the age of 122 in 1997.
A paper published by American scientists in 2015 suggests humans are designed to live for around a maximum of 115 years.
The team struggled to find anyone over 105 years old and decided the chance of finding a human who had lived for 115 years was billions to one.
Doctors and statisticians explain that a whole host of factors affect longevity.
One reason is that as doctors cure or minimise the effects of one condition, they leave a door open for another.
That’s why more people survive heart attacks, strokes and cancer but more suffer from dementia.
Public Health England blames no major strides forward in medical science for more than 20 years.
Longevity glass ceiling
Coincidentally, the world’s 10 oldest people alive are all around 115 years old – with one aged 116 and eight aged 114.
According to research by the Albert Einstein School of Medicine, humans have already hit the longevity glass ceiling.
“Demographers as well as biologists have contended there is no reason to think that the ongoing increase in maximum lifespan will end soon,” said senior researcher Jan Vijg, professor and chair of genetics.
“But our data strongly suggest that it has already been attained and that this happened in the 1990s.
“While it’s conceivable that therapeutic breakthroughs might extend human longevity beyond the limits we’ve calculated, such advances would need to overwhelm the many genetic variants that appear to collectively determine the human lifespan. Perhaps resources now being spent to increase lifespan should instead go to lengthening health span — the duration of old age spent in good health.”