People who live to age 65 are living six years longer than their grandparents did, a new study finds.
Researchers from Stanford University in California say they found that the lifespan of those who make it to retirement is increasing by three years every generation.
Previous research has suggested that humans are approaching the limit to their longevity.
But the team says its findings show that there may be no natural limit to how long humans can live and that the trend of an increasing lifespan is likely to continue.
A new study has found that the lifespan of those who live to age 65 is increasing by three years every generation (file image)
For the study, the researchers looked at birth and death records in 20 countries from 1960 to 2010 for those who lived to be older than 65.
Results showed that lifespan for those above age 65 increased by three years in every 25-year period.
This means that, on average, people are likely to live about three years longer than their parents and around six years longer than their grandparents.
While there are factors that cause fluctuations in how quickly lifespans increased, including the advent of certain antibiotics and vaccines, the variations averaged out over time.
‘The data shows that we can expect longer lives and there’s no sign of a slowdown in this trend,’ said lead researcher Dr Shripad Tuljapurkar, a professor of biology at Stanford University.
‘There’s not a limit to life that we can see, so what we can say for sure is that it’s not close enough that we can see the effect.’
Dr Tuljapurkar says the problem with most longevity studies is that the research focuses on outliers, or people who live longer than everyone else.
This includes studies on the so-called ‘Blue Zones’ – five geographic areas with low rates of chronic disease and home to some of the world’s oldest people.
However, because few people live that long, data can be misleading and why Dr Tuljapurkar wanted to look at an age that most people live to: 65 years old.
‘Our method is novel because it allows us to get rid of the fuzziness,’ he said. ‘Our focus is on the age range where we have an accurate idea of what’s going on.’
The team says if we were approaching a limit to human lifespans, the data should plateau. However, old age survival rates continued to increase like ‘a traveling wave’.
Dr Tuljapurkar admits he was surprised that the average age of death increased at a constant speed.
He says that he expected certain lifestyle factors would allow some to live longer than others.
‘There used to be so many ads about how people could live longer by, say, eating yogurt,’ Dr Tuljapurkar said.
Although yogurt may not be the key to a longer life, Dr Tuljapurkar suspected at the beginning of the study that those who are wealthier would live longer.
If this was the case, the distribution of the data would widen as rich people lived past age 65 – but the data was consistent over the 50-year study period.
Dr Tuljapurkar added, that by the time most people reached age 65, they had overcome many factors that shorten lifespan including violence and early disease.
‘As someone who would like to be a one-percenter, but is not, I’m certainly very happy to know that my odds of getting to live longer are just as good as the millionaire down the street,’ he said.