Italian Emma Morano who died aged 117 last April and Jeanne Calment of France, who famously lived to be 122 old, continue to fascinate scientists.
This led many doctors and geneticists to wonder just how long humans can live.
Last October Research Fellow Dr Xiao Dong and colleagues at the Albert Einstein College of Medicine in New York suggested human lifespan had peaked at 115 years.
He analysed demographic trends claimed there was a biological limit to maximum human lifespan.
Other agreed and said it could not increase any more because of a biological ‘barrier’ at 115 years.
But a new study by McGill University biologists argued there was no evidence that maximum lifespan has stopped increasing and the methodology used was flawed.
They said super-centenarians will become more common as average life expectancy rises.
By analysing the lifespan of the longest-living individuals from the USA, the UK, France and Japan for each year since 1968, they found no evidence for such a limit, and if such a maximum exists, it has yet to be reached or identified.
Professor Dr Siegfried Hekimi said: “Their claim rests on their identification of a plateau in the ages of maximum lifespan beginning around 1995 and close to 1997, which is the year that Jeanne Calment, a super centenarian with the longest confirmed human lifespan on record, died.
“We just don’t know what the age limit might be.
“In fact, by extending trend lines, we can show that maximum and average lifespans, could continue to increase far into the foreseeable future.”
He explained many are aware of what has happened with average lifespans.
For example in 1920 the average newborn Canadian could expect to live 60 years but a Canadian born in 1980 could expect 76 years.
Today the life expectancy has jumped to 82 years.
But he added it was impossible to predict what future lifespans in humans might look like.
Some scientists argue that technology, medical interventions and improvements in living conditions could all push back the upper limit.
He said: “It’s hard to guess.
“Three hundred years ago, many people lived only short lives.
“If we would have told them that one day most humans might live up to 100, they would have said we were crazy.
“In conclusion, the analyses described by Dong et al do not permit us to predict the trajectory that maximum lifespans will follow in the future, and hence provide no support for their central claim that the maximum lifespan of humans is ‘fixed and subject to natural constraints.’
“This is largely a product of the limited data available for analysis, owing to the challenges inherent in collecting and verifying the lifespans of extremely long-lived individuals.”
But responding to the new analysis in the journal Nature, Dr Dong disagreed and added “in the absence of solid statistical underpinning of various possible future scenarios, we feel that our interpretation of the data as pointing towards a limit to human lifespan of about 115 years remains valid.”
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