Every few years, a study lands that turns the abstract question — how long could a human possibly live? — into a single, quotable number. This July it was 156. A team of researchers, publishing in the journal npj Aging, built a mathematical model of the ageing body and used it to estimate the ceiling on human life if every fixable cause of ageing were somehow switched off, leaving only the one thing we can't yet reverse: the slow accumulation of DNA errors inside our cells.[1] The figure ricocheted around the internet in days, usually stripped of every caveat. So let's put them back.
Where the number 156 comes from
The researchers, based at the Skolkovo Institute of Science and Technology and an AI research institute in Moscow, didn't measure anyone living to 156. They built what they call an incremental model — a way of starting with a hypothetical body that doesn't age at all, then switching ageing processes back on one at a time to see how each one drags the lifespan down.
Their headline scenario isolates a single culprit: somatic mutations, the random typos that creep into a cell's DNA every time it copies itself or simply endures the chemical wear of being alive. “Somatic” just means these are mutations in ordinary body cells, not the ones you pass to your children. When the team modelled a body in which every other hallmark of ageing had been cured and only these mutations remained, the median lifespan dropped from a fantastical non-ageing baseline of 1,759 years down to about 156.[1] Widen the model to account for all the critical organs together, and the estimate settles into a range of roughly 146 to 194 years — give or take, about twice what humans manage today.
Read that carefully, because the framing matters. The 156 figure is not a prediction of how long people will live. It's an answer to a hypothetical: even if we solved almost everything else, this one unsolved problem would still stop us here.
Why your brain and heart set the ceiling
The most interesting part of the study isn't the number — it's why the body hits a wall. The answer comes down to a divide between two kinds of cells.
Most of your tissues are self-renewing. The lining of your gut, your skin, your blood: these are constantly being rebuilt from pools of stem cells, so a cell that picks up a bad mutation is eventually shed and replaced by a fresh one. That turnover acts like a reset button, diluting damage faster than it builds up. In the model, a tissue like the liver — a champion of regeneration — could in principle keep functioning for thousands of years, because continuous cell replacement all but neutralises the mutation problem.[1]
Your brain and heart don't get that luxury. Neurons and cardiomyocytes — the beating cells of the heart muscle — are, for the most part, made early and kept for life. They don't divide, which means there's no fresh copy waiting to replace a damaged one. Every mutation they collect simply stays, quietly, for decades. In the researchers' framework these post-mitotic cells become the bottleneck: they wear out first, and in doing so they set the ceiling for the whole organism.[1] It's a neat, slightly sobering idea — the two organs we most associate with the self, the thinking brain and the beating heart, are the ones least able to renew themselves.
How this fits a longer argument
This isn't the first time science has tried to nail down a hard limit, and the new model lands in the middle of a long-running and genuinely unsettled debate.
On one side sits evidence for a fixed ceiling. A widely cited 2016 analysis in Nature argued that gains in survival among the very oldest people have stalled since the 1990s, and that the age of the world's oldest person hasn't crept upward — suggesting human lifespan runs into a natural wall somewhere around 115, with 122 as a rare outlier.[2] That outlier is real: Jeanne Calment, a French woman who died in 1997, remains the oldest verified human at 122, and no one has come close since. A separate 2021 study took a completely different route — tracking the body's declining ability to bounce back from stress using routine blood markers — and independently arrived at an absolute limit of roughly 120 to 150 years, the point at which resilience hits zero.[3] That the new mutation model lands in the same neighbourhood is striking, given it started from entirely different assumptions.
There's also a deeper biological hint that mutations matter. When researchers sequenced the cells of sixteen mammal species in 2022, they found that the somatic mutation rate scaled inversely with lifespan: short-lived mice rack up mutations fast, long-lived humans slowly — but every species arrived at roughly the same mutation burden by the end of its life.[4] It looks less like a coincidence than like a clock.
Not everyone thinks the ceiling is quite so firm. Demographers who study “longevity pioneers” have argued that death rates actually plateau in extreme old age rather than climbing forever, which would leave a little more room at the top and makes a record like Calment's statistically plausible rather than impossible.[5] The honest summary is that the exact number is contested — but almost everyone in the field agrees the ceiling exists, and that it's far higher than the life expectancy any country currently achieves.
The caveats the headlines skipped
Here's the part that got lost in translation. A model is only as good as its assumptions, and this one makes a whopping one: that we could eliminate every other hallmark of ageing and leave only mutations. We can't. Nobody can. The authors themselves are careful about this — they note explicitly that somatic mutations, though a significant driver, “cannot alone account for observed mortality,” implying that other ageing processes like protein damage, mitochondrial decline and epigenetic drift contribute comparably.[1] In other words, the 156 figure describes a world we don't live in and can't yet build.
It's also worth separating the theoretical ceiling from the practical one. The oldest verified person reached 122; the odds of any individual today even reaching 100 remain low. A sobering 2024 analysis in Nature Aging looked at the longest-lived populations on Earth and found that the once-rapid rise in life expectancy has actually slowed since 1990 — concluding that radical life extension is implausible this century unless we genuinely learn to slow the biology of ageing itself.[6] So there are really two numbers in play: a distant theoretical maximum near 156, and the messy human reality, where most people are still lost decades earlier to heart disease, cancer and dementia. The gap between those two is where all the actual living happens.
So what does this mean for you?
Practically? On its own, almost nothing — and that's the honest answer. You can't buy your way toward 156. There is no supplement, injection or protocol shown to raise the human ceiling, and anyone selling you one is selling a fantasy. The clearest reader-friendly lesson from the mutation model is actually a defensive one: since your least renewable cells set the limit, protecting your brain and cardiovascular health over decades is the closest thing to playing the long game.
And that circles back to the least glamorous advice in all of longevity science, which happens to be the best supported. Almost nobody dies of the theoretical maximum; people die of the diseases that arrive long before it. Closing that gap is what the evidence actually lets you do — and it doesn't require a lab. It's the same short list every time: don't smoke, build and keep your cardiorespiratory fitness, protect your sleep, eat in a way you can sustain, and guard your metabolic health. Those are the levers with real human data behind them, and they add years to your life now, whatever the ultimate ceiling turns out to be.
It's tempting to read a headline like “humans could live to 156” as a promise. It isn't one. It's a thought experiment about the deep architecture of ageing — a reminder that even our least-renewable cells set a boundary, and that the frontier of reversing biological ageing still has to reckon with the parts of us that never get a second copy. The gap between today's reality and that far-off ceiling is enormous, and it's filled almost entirely with problems — the accumulation of worn-out ‘zombie’ cells, failing metabolism, chronic disease — that we're only beginning to understand. For now, 156 is a fascinating number to think about. It is not a number to plan your life around.
Common questions
What is the maximum human lifespan?
The oldest verified human, Jeanne Calment, reached 122. Demographers who study the very old put a practical ceiling somewhere around 120 to 130 years for people alive today. The 2026 npj Aging model estimated that if every reversible cause of ageing were switched off and only DNA mutations remained, the median lifespan would land near 156 years, with a full-organ range of 146 to 194. That 156 figure is a theoretical upper bound from a mathematical model, not a prediction that anyone will actually live that long soon.
Why do neurons and heart cells limit how long we can live?
Most tissues repair themselves by replacing worn-out cells with fresh ones, which dilutes the DNA damage that builds up over time. But neurons in the brain and cardiomyocytes in the heart are largely made once and kept for life; they don't divide, so mutations accumulate in them with no way to reset the clock. In the model these non-dividing cells become the bottleneck that sets the ceiling, while a self-renewing organ like the liver could in theory keep working for thousands of years.
Can I do anything to reach the maximum human lifespan?
Nothing you can buy today moves the theoretical ceiling. But almost no one dies of the ceiling; people die decades earlier of heart disease, cancer, stroke and dementia. Closing the gap between your likely lifespan and that limit is about the unglamorous basics with the strongest evidence: not smoking, regular exercise that builds cardiorespiratory fitness, decent sleep, a sensible diet and protecting your metabolic health. Those add years now, whatever the ultimate maximum turns out to be.