Can humans reach even older age? We haven't maxed out yet, some scientists say

Credit: CC0 Public Domain

On the day that one becomes an octogenarian, nature bestows a mathematical birthday gift: a gradual reprieve from the relentlessly increasing likelihood that he or she will die in the coming year.

That gift may come as small comfort against the growing creakiness of joints and the still-mounting probability that the end is nigh. But an analysis of close to 4,000 very long-lived Italians suggests that the rise in the risk of imminent death continues to slow until the age of 105. After that, researchers estimate, the chance of making it to see another birthday holds steady at roughly 50-50.

Perhaps it's "nothing to blow a trumpet about," said University of California, Berkeley demographer Kenneth Wachter. But at least the mortality rate levels off, the data suggest.

Wachter and colleagues from universities in Italy and Germany published their findings in Friday's edition of the journal Science.

For humankind in general, these findings hint at an intriguing, if largely theoretical, prospect: that the maximum possible human lifespan—essentially, the species' design limit—has not yet been reached. It may even be extended by means as yet undiscovered.

If the "oldest old" tell us how long we could live, then many centenarians could, in principle, get even older. And maybe older still with the right elixir.

"This data suggest our genetic heritage is permissive," Wachter said. "Our bodies are not put together so that at some point, everything goes wrong."

Indeed, he said, there's reason to believe that some humans could beat the current longevity record of 122, which was set in 1997 by Jeanne Louise Calment of France.

The new research contributes to a debate that has preoccupied poets and philosophers for as long as they have set pen to paper. For instance, the historian Gaius Plinius Secundus, better known as Pliny the Elder, maintained a running tally of long-lived persons and pondered the significance of their longevity.

Scientists have been in the fray since at least 1825. That's when the British mathematician and actuary Benjamin Gompertz published the first models of human mortality and asked when, and whether, we must die.

In the new study, the international team of demographers and statisticians took advantage of the proliferation of people who live well past their 100th birthday. By calculating and analyzing the death rates of 3,836 well-documented cases of Italians who lived to 105 or beyond and combining them with existing data on mortality rates, the researchers created a model that reveals the statistical likelihood of death in every year of the human lifespan from 65 to 105.

Established demographic data show that after 65, people grow more likely to die with every passing year. And the math is unforgiving: Each year after 65, the probability of death rises at a pace that's double what it was the previous year.

But when the researchers added the 3,836 long-lived Italians to the earlier data, they saw that this doubling held up only until the average human's 80th birthday. After that, the rate of increase began to slow.

For the lucky humans who made it all the way out to 105, that annual increase in the probability of death seemed to stop.

The authors also showed that the annual mortality rate in those aged over 105 declined slightly with each successive birth year, such that those born more recently tended to live longer.

This pattern "strongly suggests that longevity is continuing to increase over time and that a limit, if any, has not been reached," wrote the team, which included demographer James W. Vaupel of the Max Planck Institute for Demographic Research in Germany.

"Our results contribute to a recently rekindled debate about the existence of a fixed maximum life span for humans," they added. In any event, it raises "doubt that any limit is as yet in view."

To University of Illinois epidemiologist S. Jay Olshansky, the evidence for the counter-argument—that there is a strict limit to the maximum human lifespan and we have reached it already—is right there in the new Italian data.

"The conclusion that they've come to, which is that there is no upper limit to life, is unreasonable," said Olshansky, who was not involved in the new research.

By the time people reach these extreme ages, at least half disappear every year. And since there are so few of them to begin with, this harsh reality "tells us the real story," he said.

"If 100 people survive to age 110 out of billions—which is exactly what has happened—what difference does it make if it's 50 or 60 that die before their next birthday?" he said. It's just not persuasive to use such a small difference, drawn from such a tiny population of humans, to conclude anything about the longevity of humans in general. Statistically speaking, he said, "the tail of the survival distribution does not wag the dog."

This should be abundantly clear to anyone who has ever been around senior citizens, he noted. "Human bodies are not intended for long-term use, and when we do manage to get them to operate past a century, plenty of age-related diseases accumulate," Olshansky said.

Geneticist Jan Vijg of the Albert Einstein College of Medicine in New York believes he has seen the limit of the human lifespan, and said it ceased its upward trajectory in the 1990s with the death of Calment. (The Frenchwoman ascribed her longevity to the fact that she didn't worry much and had a diet rich in olive oil, port wine and chocolate, which she consumed at a rate of more than 2 pounds a week.)

For a study published in 2016 in the journal Nature, Vijg and his colleagues calculated that if scientists could cobble together 10,000 people who had reached the age of 110—a big if—only one of them would be expected to live beyond 125.

Vijg, who was not involved in the new study, praised the authors' ability to generate a new and well-documented database of very long-lived individuals. But "their data does not substantiate the claim" that the maximum limit to human lifespan goes out much further than it has already, he said.

"There is a ceiling. At the end of the day there is a ceiling," says Vijg.

Vijg says he is "amazed" at the vigor of the scientific debate around an issue that is so distant from the reality of ordinary mortals. The outer limit of the human lifespan is an "intriguing scientific debate," he said. But improving the average lifespan of all humans—by extending gains in nutrition, creating new medicines and addressing the causes of infectious diseases—is a better way to spend one's energy, he adds.

"There is lots of opportunity here, no doubt," Vijg said. "We can improve quality of life more and maybe give more people more life."

What do the new numbers tell us about life and death at the outer limits of the human lifespan?

Think of aging as if it's a treadmill: You're power-walking along in your early 60s, and around the time of your 65th birthday, the pace at which the treads move under your feet starts to pick up.

With each passing year, the speed grows. In fact, the rate of this change doubles every year.

Fail to keep up and you die.

Around the time of your 80th birthday, the rate of this increase begins to slow. You're still more likely to die with each passing year than you were the year before, but your treadmill isn't speeding up quite as much.

And by the time you reach the age of 105—surprise! - the yearly quickening ceases altogether.

Now imagine yourself in a gym filled with treadmills, each occupied by people of different ages. The 105-year-olds are running faster than everyone who is younger. And they are falling off their treadmills—dying—at a much higher rate than are the 70-year-olds. Indeed, only about half of them make it to 106.

But if they do, they get a little break: Their treadmills are still the fastest in the gym, but at least they're not getting any faster.

Explore further

Maximum human lifespan has already been reached, researchers conclude

More information: E. Barbi at Sapienza University of Rome in Rome, Italy el al., "The plateau of human mortality: Demography of longevity pioneers," Science (2018). … 1126/science.aat3119
Journal information: Science

©2018 Los Angeles Times
Distributed by Tribune Content Agency, LLC.

Citation: Can humans reach even older age? We haven't maxed out yet, some scientists say (2018, July 1) retrieved 24 August 2019 from
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Feedback to editors

User comments

Jul 01, 2018
There is no advantage to extending the human lifespan further than it has already reached. It would be one thing to have people 100 years old with the physical and mental abilities of someone far younger, but that isn't in the cards. People who have reached great age, even if they are in good health for their age, tend to take the view that they have lived too long. The desire to live even longer is generally held by people much younger than the old folks themselves. Perhaps it's a fear of death that engenders such thinking, but the reality is that old folks tend to be at peace with their impending death. They just don't want to keep living for longer and longer periods if their is no vitality left in their bodies or their brains, and they do not want to be incapacitated but still alive. They want "the big one" to hit them so they have a quick death when it comes.

Jul 01, 2018
My father is 101, still there mentally, still lives by himself with, recently, daily help during the day. He was a physicist, still reads physics, rants about Trump being the worst president of the republic etc. But, those of us who have seen what > 100 looks like -- it's not for wusses.

He slipped and rubbed his arm on his bed mattress -- just cloth on skin. Looks worse than when I took a spill on my bike, flesh on tar at speed -- there simply is no fat left in his skin.

He can still dress himself in the morning, but after he makes his breakfast (1.5 hrs), he needs a nap. After that, the energy to get his shoes on is gone and needs help. There are never less than several medical appointments a week. Stem cells that produce blood tend to be nearly depleted by 96, so keeping his sodium and iron levels took the genius of a blood specialists (remember, most doctors have never seen or treated anyone over 100, even in "old" areas) to fix that multi-year problem. Not easy.

Jul 01, 2018
Completely flawed. The 100 in a billion, where is the majority over 100? Japan? US? Where! Would like to see the global demographics.

Jul 02, 2018
Well, so far, we've hardly thought of our kind to be able to stay healthy enough to massively reach that famous 100 y/o barrier. If people could stop dying right after they retire from work, that'd be great enough.
Humans can reach even older age. But not naturally. We'll need to take other roads, other means.
And make sure people living older won't look like rotten potatoes, too. There would be close to no point in living older if you can't do anything else than breathing.

Jul 02, 2018
The ONE who created us saw fit to limit our maximum age to around 120 years
even though people just before and after the great flood used to live till about 969 years - max as recorded in the bible. Moses makes it out to be 70/80 years of toil and suffering (Psalm 90:10)

But due to our sinful nature who in his or her right mind would want to live longer than 100 years in this time and age?

As the first two comments make quite clear - living past 70 years is not for the faint of heart.

It's best to make right with God as soon as possible - accept Jesus as Lord and Savior and then be at peace with death whilst spreading the good news - that there will be a resurrection into a new life without sin, pain, suffering and death.

Jul 02, 2018

Anti-aging therapies are already out there. Metformin, a drug used to treat diabetes, is already being used by non-diabetic researchers, doctors and patients for it's longevity characteristics. Also being studied is rapamycin found on Easter Island in the 1960's. Researchers have seen such promising results they're giving it to their pets to prolong their lives. These drugs are promising to not only extend life, but in a healthy state so that there is a very short period of morbidity at the end. If you don't think any of this is real, just take note
that some insurance agency underwriters will no longer underwrite annuities because profits on those are based life expectancy, which they predict will be unpredictable in the very near future.

Jul 02, 2018
Humans have had fire with flickering broadband infrared light for 3.7 million years. We act like we were made for a red dwarf sun. Ir has a strong effect on mitochondria young or aged. The spine and thyroid are made for ir from a fire. Read New hope for eyes damaged by Parkinson's disease on medicalxpress. And Researchers' papers find concept of using light to image, potentially treat PTSD From, Home Biology Plants & Animals November 15, 2016
Light therapy could save bees from deadly pesticides Some of our modern diseases may come from lack of exposure to ir light. The effect of ir light on mitochondria is like photosynthesis in plants. It provides the energy to repair cells in the entire body and provide energy for cell function. The thyroid descends from the top of the throat so that it can be exposed to the ir light from a fire. Compare the jaw size and thyroid placment of other animals. Want to live longer? Expose your blood through your lungs, major organs, joints, etc

Jul 02, 2018
Home Neuroscience January 10, 2017
Glia, not neurons, are most affected by brain aging medical express
Housekeepers' of the brain renew themselves more quickly than first thought medxpress
Will we hear the light? Surprising discovery that infrared can activate heart and ear cells medicalxpress
Ir even penetrates the thin bones of the skull. The mitochondria respond and communicate by microfascia or microtubules. Chopped ir has an effect on hart muscle and nerves in the ears. Read the articles and see the potential benefit for all ages.

Jul 02, 2018
When the Social Security administration chose sixty-five as the age to collect retirement benefits, the average lifespan was sixty-four years. The average lifespan has risen since then and will continue to rise resulting from breakthrough research and Google billionaires' desire for more time to spend their fortunes. I want to live a very long time because I enjoy being alive. It's sad to hear that someone wants to throw in the towel not because of physical frailty but from loneliness when a spouse dies and that the reason they want to leave this life is to "join" their departed mates in the "next life". The isolation of people in their old age is the problem, not just physical infirmity. Society does little to address this failure to see the elderly as anything but a drag on our precious economy. We are animals, and are hardwired to survive at any cost. There will be an elixir one day that genuinely reverses aging, and I'll fight tooth and nail to get my hands on it.

Jul 02, 2018
I think the science fiction of the 50s, 6os and early 70s has it right. When 80 is 50 now, and then 110 will be the 80 in physical age. If the you fix the legs and back from waring out, you increase the life span due to increased exercise and cardio vascular health. I hear it, and see it, and feel it. Fix the legs and back.

Jul 02, 2018
This viewpoint of "aging" is why we have made no progress in actually moving our peak capability age much at all. Aging is a genetic default shut down that starts right after sexual maturity. The body begins to stop repairing its genes and it cells and while the process has peaks and slow downs as the article points out - the end point is the remarkably the same. People that live past 100 are statistical outliers and we learn little by studying them - unless that is our goal - to be decrepit. Until we are able to extend our peak physical and mental optimum age - living into decrepitude as our bodies essentially decompose around an active brain - isn't an attractive concept or motivation for increasing longevity. We must interfere with our genetic default to stop repair and maintenance - then we might look like 30 when we reach 150.

Jul 05, 2018
There is no advantage to extending the human lifespan further than it has already reached. It would be one thing to have people 100 years old with the physical and mental abilities of someone far younger, but that isn't in the cards. People who have reached great age, even if they are in good health for their age, tend to take the view that they have lived too long. The desire to live even longer is generally held by people much younger than the old folks themselves.

But we need more statistics to say that as well. There are counterexamples for sure. Say, Sweden's oldest blogger at 105 says when she started blogging at 100 it was to make new friends, and it worked. And the French cyclist that has shown that proper training - i.e. mixed up, same as food should be - works after 100 in gaining muscle mass, so you can apparently always improve quality (if not length) of life.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more