The Animal That Doesn't Age — What Naked Mole-Rat Teaches Us About Aging

Apr 4
6 min read

Updated: 1 hour ago

Scientists tracked 3,000 animals over 35 years and found a surprising result that is reshaping aging, longevity, and health-span research.

TA Medical Research Team · 5 min read · Longevity Science

Every living creature ages. Every cell accumulates damage. Every body, given enough time, begins to fail. This is considered one of biology's most reliable rules — so consistent, so universal, that scientists even have a mathematical formula for it. It is called Gompertz's law, and it states that the risk of death doubles roughly every eight years as we grow older. In humans. In mice. In horses. In virtually every mammal ever studied.

Except one.

01 Meet the Animal Biology Cannot Explain

The naked mole-rat is not a conventionally appealing creature. Mouse-sized, wrinkled, nearly hairless, and almost entirely blind, it lives underground in tight colonies in the semi-arid regions of sub-Saharan Africa. It has no apparent survival advantages that would make it an obvious candidate for the world's most extraordinary longevity study.

And yet. A study by researchers at Calico Life Sciences, published in the journal eLife, analyzed the lifespan records of more than 3,000 naked mole-rats collected over 35 years. What they found stopped the aging research community in its tracks.

The naked mole-rat's risk of death does not increase with age. At all. A one-year-old and a twenty-year-old mole-rat carry essentially the same daily probability of dying. The risk does not double. It does not rise. It stays flat — for decades.

30+

Years of confirmed lifespan — five times longer than expected for its body size

3,000

Individual animals tracked across 35 years in the Calico Life Sciences study

Increase in mortality risk with age — defying Gompertz's law entirely

25x

Beyond reproductive maturity with no detectable demographic aging observed

02 Why This Is So Surprising

In most mammals — including humans — the body's risk of death follows a predictable curve. It starts low in young adulthood and climbs steadily upward, doubling at regular intervals. This is Gompertz's law, first described in 1825 and confirmed in virtually every species studied since.

The formula reflects something we all sense intuitively: the older we get, the more our biological systems have been worn down. Damage accumulates. Repair slows. Risk rises. Here is how the naked mole-rat compares to what we consider normal:

Species	What happens to mortality risk with age	Pattern
Humans	Risk doubles roughly every 7 to 8 years after young adulthood	Exponential rise
Mice	Risk rises sharply and exponentially from around 550 days of age	Steep Gompertzian curve
Horses	Risk climbs steadily after maturity, consistent with Gompertz's law	Gradual exponential rise
Naked mole-rat	Risk remains essentially constant from maturity onward — for 20+ years	Flat — no Gompertzian aging detected

The researchers formally classify the naked mole-rat as a non-aging mammal — the only one ever to receive that designation based on statistically rigorous analysis of a large population dataset. No other mammal studied to date has shown this pattern.

03 How Does It Do This?

The naked mole-rat still accumulates cellular damage over time — it is not immune to the passage of years. What makes it different is what it does with that damage. Several remarkable biological traits have been identified:

Exceptional DNA repair. Highly efficient systems for detecting and correcting genetic damage prevent the cascade of errors that drives normal aging.

Sustained protein stability. Protein quality control — the folding, repairing, and removal of damaged proteins — is maintained at near-youthful levels throughout their entire lives.

Preserved mitochondrial function. The energy-generating structures inside cells remain functional and efficient well into old age — a trait that typically declines significantly in aging mammals.

Negligible cancer rates. Despite their long lives, cancer is extremely rare — linked to their unusually robust cellular maintenance systems.

No reproductive senescence. Breeding females retain fertility even past 30 years, showing no equivalent of menopause — almost unheard-of at this age in any mammal.

Maintained neurogenesis. New brain cell formation continues for at least two decades — a process that typically slows dramatically in aging mammals.

There may be another reason these animals stay healthy for so long. In most bodies, old and damaged cells slowly build up over time, interfering with how tissues work. But in naked mole-rats, research suggests these worn-out cells are cleared away early — almost like routine maintenance. A study from Kumamoto University in Japan found that these animals may naturally remove aging cells before they can accumulate. Instead of letting damage build up, the body clears it away, helping everything continue to function smoothly for much longer.

The key insight

The naked mole-rat does not escape all damage. It appears to maintain the repair and protection systems that slow the consequences of that damage — keeping its biological machinery functioning at near-youthful levels for far longer than any other known mammal.

04 What Does This Mean for Us?

The naked mole-rat does not offer a blueprint for human immortality. But its existence does something important: it demonstrates that the Gompertz curve is not biologically inevitable. It is not a fixed law of nature. It is a pattern — one that, under the right biological conditions, can be broken.

For most of the history of biology, the progressive rise in mortality risk with age was treated as given — like gravity. You could slow it, perhaps. But you could not fundamentally alter it. The naked mole-rat says otherwise.

"This absence of hazard increase with age, in defiance of Gompertz's law, uniquely identifies the naked mole-rat as a non-aging mammal, confirming its status as an exceptional model for biogerontology."

— Ruby, Smith & Buffenstein, eLife (2018). Calico Life Sciences LLC.

For researchers studying NAD+ and the biology of cellular aging, the connection is direct. The biological systems the naked mole-rat maintains so well — DNA repair, mitochondrial function, protein stability, cellular energy — are the same systems that NAD+ supports in all mammals, including humans. NAD+ levels fall by roughly half between our 20s and our 50s. As they fall, the repair and maintenance systems they power become progressively less effective — one of the central mechanisms driving the aging we experience.

The question the mole-rat raises is not simply can aging be slowed, but what would it look like to genuinely maintain the repair systems that keep aging at bay. This is increasingly the direction aging science is moving globally — from Harvard to Tokyo to Oslo.

05 What This Tells Us About

How We Can Live

None of us will live like a naked mole-rat. But the systems that determine biological age are not simply clocks winding down. They are active maintenance networks — and they respond to how we live. The same repair mechanisms the mole-rat sustains so effectively are systems research shows we can support:

Supporting NAD+ levels. NAD+ is central to DNA repair, mitochondrial function, and the activation of protective sirtuin proteins — the exact systems the naked mole-rat excels at maintaining. Its levels fall by roughly half between our 20s and 50s, and researchers worldwide are actively studying how to address this decline.

Regular physical movement. Exercise raises NAD+ in muscle, stimulates mitochondrial renewal, and activates many of the same cellular repair pathways. Even a single aerobic session measurably boosts NAD+ metabolism in immune cells.

Quality sleep. The overnight period is when the body conducts much of its cellular maintenance — directly affecting the efficiency of DNA repair and NAD+-dependent recovery systems.

A diet that supports cellular systems. Whole foods, plant diversity, and reduction of chronic metabolic stress all support the maintenance networks associated with longer, healthier life.

The naked mole-rat does not extend its life by doing something radical. It extends it by maintaining — for an extraordinarily long time — the same biological systems that all mammals

06 A New Way of Thinking About Aging

There is something quietly remarkable about the naked mole-rat's existence. It simply goes about its life — maintaining its colonies, repairing its DNA, keeping its cells in order — without any of the progressive deterioration we have always considered inevitable.

For scientists, it represents a proof of concept: the biological processes behind aging are not fixed. For the rest of us, it is an invitation to think differently about what is possible — not just in terms of how long we might live, but in terms of how well.

The goal of longevity research is not to make everyone live to 150. It is to extend the years in which we feel capable, energetic, resilient, and present — what researchers call healthspan. The naked mole-rat, improbable as it is, points toward a biology that makes more of that possible.

Research continues. The answers are not all in yet. But the question — whether the Gompertz curve is destiny or simply a default — is now, for the first time, genuinely open.

Primary Research Source: Ruby J.G., Smith M., Buffenstein R. (2018). "Naked mole-rat mortality rates defy Gompertzian laws by not increasing with age." eLife, 7:e31157. DOI: 10.7554/eLife.31157. Calico Life Sciences LLC, South San Francisco.

This article is for educational and informational purposes only. It reflects published peer-reviewed research and is not intended as medical advice. Please consult a healthcare professional for personal health decisions.

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