The quest for immortality: How science is trying to end ageing

Last September, Russian President Vladimir Putin and Chinese President Xi Jinping, both 72, were caught on a hot mic discussing whether humans could push 150 or even achieve immortality. It is a question that has fascinated the brightest minds for a while now.

For over five years, China’s academic circles had been talking about the authenticity of a stone inscription that archaeologists found on the Tibetan Plateau, near Zhaling Lake in Qinghai province. In June 2025, a report based on these inscriptions claimed that, in 221 BCE, there was a state-sponsored expedition launched by China’s first emperor, Qin Shi Huang, to the mythical Mount Kunlun in search of yao, or the elixir of life.

Qin Shi Huang was obsessed with longevity. During his reign, he commissioned the Terracotta Army—a vast collection of life-sized clay soldiers, chariots and horses—to protect him in the afterlife. He had also sent many missions eastward, towards Japan, to find the key to immortality.

But until now, there had been no evidence that he had dispatched men westward, towards Tibet and India, in search of yao.

When the report was published, sceptics said it could be modern forgery and questioned whether the emperor’s men could have reached the plateau given the harsh conditions. Nevertheless, almost two weeks after the Xi-Putin exchange, China’s National Cultural Heritage Administration concluded that a group of determined emissaries had indeed made the trip.

The modern quest for longevity and research on ageing, referred to as biogerontology, emerged as a distinct discipline only in the late 1980s—surprisingly recent for a science that concerns the entire human race.

The modern Qin Shi Huangs driving this quest include multi-billionaires of Silicon Valley and rulers like Xi and Saudi Crown Prince Mohammed bin Salman. Their motivation is anything from personal ambition to paranoia, and profiteering to geopolitical power. Regardless, unlike any other time in human history, enormous sums of money are flowing into the fight against ageing. The scientific world is now on a mission to create a modern-day yao that could ultimately alter the course of mankind.

Myth-busters

In the 1930s, American biochemist Clive McCay—who would later create rations for US soldiers during World War II—did a food experiment on rats. He found that rats that were put on a restricted diet lived up to twice as long as those on a standard diet. They also showed delayed signs of ageing and better health indicators. McCay published the study in 1935 in the Journal of Nutrition, but it found few takers because fighting ageing was not a top priority then.

Nevertheless, in the coming decades, it was seen that diet could impact longevity in several species, from single-celled yeast to even complex mammals. The most significant of these was a humble nematode worm from the compost heaps of Bristol, England. In the early 1960s, Sydney Brenner was looking for an organism to understand how genes orchestrate multicellular development and behaviour. He wanted something simple enough to map entirely, yet complex enough to mirror animal life. That’s where the worms came in. They had a short lifespan, genetic manipulability and could reproduce rapidly—all factors that helped the study.

In a 2017 interview, he recounted his reasoning: “I wanted something where I could see every cell, count them, and watch the whole animal develop from egg to adult.” In 1963, he started culturing worms on petri dishes smeared with E. coli bacteria as food. He once smuggled a vial of worms through customs by declaring them “live bait”. His colleagues scoffed; one called it a “joke organism” during early presentations, as Brenner recalled in his 2002 Nobel lecture.

In the early 1980s, Cynthia Kenyon, a young postdoc, joined Brenner’s lab; she was drawn to the potential of the worm study. Like Brenner, she, too, faced scepticism when she said that ageing was subject to genetic regulation. One fellow scientist, worried that she had gone “over the edge”, warned her that if she continued to insist on it, she would soon fall off the earth altogether.

But, in 1993, her experiments on C. elegans (the biological name of the worm) showed that a single mutation on a gene named daf-2 could double lifespan—from two weeks to a month—while keeping the worms fertile and vigorous. Kenyon later said the experience was “like witnessing a miracle”. The genetically altered worms not only lived longer, but also retained firm muscle tone, kept squirming actively, searched for food and appeared remarkably youthful. In contrast, normal worms of the same two-week age were largely inactive, flabby and looked old. Since then, Kenyon and her team have made more discoveries, including the role of a gene called daf-16, which switches other genes on or off.

By making small changes in the worm genome, they were able to extend a worm’s life up to six times the normal length, with little loss of vitality until very late in life. The takeaway was clear: ageing was not set in stone.

As Kenyon’s discoveries drew global attention, Indian-origin biologist Suresh Rattan helped give shape to ageing research. He coined the term ‘biogerontology’ to highlight the molecular and cellular study of ageing—distinct from gerontology’s social and clinical focus. The term gained prominence in 2000 with Rattan’s paper Biogerontology: The Next Step in the Annals of the New York Academy of Sciences.

However, there were challenges: research on ageing was underfunded, overshadowed by disease-specific studies, and tainted by a historical stigma of “anti-ageing” quackery. Most scientists focused on describing ageing, not intervening, and public funding prioritised incremental gains over radical life extension.

Then came Aubrey de Grey, a computer scientist turned biogerontologist, who saw ageing as an “engineering problem”—a matter of damage that could be repaired. With his long, flowing brown beard, he looked more like a prophet than a scientist. And he did predict things that raised many eyebrows.

In 2003, together with tech entrepreneur David Gobel, de Grey founded the Methuselah Foundation in Springfield, Virginia. Its mission was to “make 90 the new 50 by 2030”. The foundation—named after a biblical patriarch who is said to have lived 969 years—became key in initiating “longevity craze” in Silicon Valley.

In an exclusive interaction with THE WEEK, de Grey said he never really needed a eureka moment to realise that ageing was a problem that could be solved. “It was the other way around,” he said. “I spent most of my early life fully aware that ageing was a problem that could, in principle, be solved. What I didn’t realise was that other people didn’t see it that way.”

With a degree in computer science from the University of Cambridge, de Grey originally went into a career in software engineering. Only after marrying Adelaide Carpenter, a biologist, in 1991, did he realise that people—including biologists—actually didn’t think much about ageing. “I thought that was terrible,” he said. “As a computer scientist, I was doing fine, but I realised I had to change fields, because nobody else was working on this, and it was a serious problem.”

As he transitioned into gerontology, de Grey got a PhD in biology. As an alumnus of Cambridge, he could apply for a doctoral degree by submitting a body of research and defending it before a panel of examiners. De Grey received his doctorate in late 2000.

“When I first started this work, I was only speaking to people within the academic community,” he said. “I also had a small following online through discussion groups, but that was about it. Around 2003, I began to realise that maybe I could do something more directly myself. I was encouraged and supported by a number of people, especially [futurist] David Gobel, with whom I co-founded the Methuselah Foundation. From there, everything started to accelerate. The media began paying attention, I was invited to speak at TED, and those opportunities helped the community move forward more quickly.”

His argument was that if we could fix a damaged car or aircraft, we could do the same with the human body. The project then became about attracting innovative and unconventional talent that could “fix” the issues of ageing.

In 2003, the foundation launched the Methuselah Mouse Prize (Mprize), which offered cash prizes for extending mouse lifespans and reversing signs of ageing. The first winner was Andrzej Bartke, who developed a genetic modification enabling a mouse to live 1,819 days—roughly 180 human years. The initiative helped steer biogerontology toward measurable goals, making ageing research both credible and compelling.

Around the same time, de Grey introduced a scientific framework known as Strategies for Engineered Negligible Senescence (SENS). Senescence is the process of deterioration with age; any organism that shows no meaningful signs of ageing has ‘negligible senescence’.

SENS identifies seven categories of molecular and cellular damage that accumulate with age—such as mitochondrial mutations and senescent cell build-up—which de Grey considered the root causes of ageing.

He proposed targeted interventions to repair each type of damage, comparing the process to maintaining a car to prevent mechanical failure. He argued that repairing damage could be easier than slowing its formation.

If all seven damage types could be addressed simultaneously, he suggested, ageing might be postponed long enough for continual refinements—potentially extending human lifespans even beyond 1,000 years. He linked this vision to a concept he coined in 2004—Longevity Escape Velocity (LEV)—which is the point at which advances in anti-ageing science outpace the rate of biological deterioration. In simple terms, it is the moment when medicine can repair age-related damage faster than it accumulates, allowing humans to effectively “outrun” ageing.

Though many critics dismissed de Grey’s ideas as speculative, SENS, and later the Hallmarks of Aging, a 2013 framework by Carlos López-Otín and colleagues (see graphics), became key theoretical models of modern longevity science. The two models overlap substantially and have together formed the backbone of the field in the past 25 years.

“The idea that ageing is a medical problem is something I’ve largely been able to persuade people of,” said de Grey. “What has been more difficult is getting people to accept that it’s a problem we have any chance of solving in the near future. Most assume it is far too hard and will take centuries before we see any real progress. That’s where the whole concept of longevity escape velocity comes in.”

However, de Grey did clarify that he has never claimed humanity will completely solve ageing in the next few decades. “What I have said is that we have a chance to make enough progress against ageing to keep people healthy—and therefore alive—for at least 20 more years beyond what is currently possible. The key point is that within those 20 years, we’ll have the opportunity to make further advances, which could add another 20 years, and so on. Importantly, these additional gains will benefit the same individuals who benefited from the earlier ones. And the reason this works is that progress comes through rejuvenation—repairing the damage in the body—rather than merely slowing ageing.”

Funders of the future

When the dot-com bubble—marked by the rapid rise of US tech stocks in the late 1990s—burst in 2000–2001, it wiped out trillions in market value and triggered a crisis of confidence. The collapse exposed the risks of speculative software ventures, pushing many toward “hard tech” with tangible, real-world impact. Longevity research fit that bill perfectly—it promised transformative returns, and many entrepreneurs who had weathered the crash, now in their 40s and 50s, saw personal meaning in extending healthy lifespans.

Silicon Valley, de Grey told THE WEEK, provided the ideal mix of money and talent to push his ideas forward. Progress, he said, would have been far slower without a handful of visionary backers, chief among them Peter Thiel. After selling PayPal to eBay in 2002, Thiel poured $3.5 million into the Methuselah Foundation and another $6 million in matched funds, starting a wave of post-crash investment into SENS-inspired startups.

By the 2010s, there was a full-blown ‘longevity industry’, with the Bay Area in San Francisco as its epicentre. Unity Biotechnology, backed by Thiel and Amazon founder Jeff Bezos; Calico Labs, backed by Google co-founders Larry Page and Sergey Brin; and Human Longevity Inc., backed by serial entrepreneur Peter Diamandis. Genomics and senolytics—drugs that clear away old, dysfunctional cells—were the domains that got more attention during this first wave.

More recent entrants include Elevian (2017, which Mark Zuckerberg has reportedly shown interest in), Altos Labs (2022, with $3 billion from Bezos and Yuri Milner), Retro Biosciences (2022, fuelled by Sam Altman's $180 million), and NewLimit (2022, driven by Brian Armstrong’s investment).

Asked if the longevity agenda is shaped by the personal desires of billionaires, de Grey said: “Many wealthy individuals invest in this field because they want to live longer—and that’s fine. Even if their motives are selfish, the benefits will extend to everyone.”

One of these men is American entrepreneur Bryan Johnson, whose data-driven lifestyle interventions (‘Blueprint’ protocol) have pulled many people into the anti-ageing conversation. “His work is all about leveraging the things we can already do, be it supplements, lifestyle changes or other existing interventions,” said de Grey. “And that is valuable—it certainly helps people live a little longer in a healthier state. But only a little bit longer. I think Bryan’s main contribution is that he has gotten people to think seriously about ageing. A lot of people don’t like the way he does that, and honestly, I’m not sure I would do it the way he does. But that is fine. It is very important to have diversity of messaging, to have people expressing the same ultimate goal in different ways.”

The real problem, he said, was that many ignored expert advice on where the money should go. “Bezos and Altos have used funds effectively, but there are disastrous counterexamples,” he said. “The worst is Calico—Larry Page and Sergey Brin poured billions down the drain because they wouldn’t listen to experts like me.”

His criticism of Calico stems from its focus on basic biological research into ageing, rather than on practical repair strategies central to his SENS framework. THE WEEK reached out to Kenyon, who is now Calico’s vice president for ageing research, but she was unavailable for comment.

Some SENS-inspired therapies are already in the market, but only in partial forms—not yet the full “ageing repair” vision de Grey described. Asked which of the seven SENS “damage categories” are closest to clinical application, de Grey said: “Stem cell therapies—whether actual transplants or partial reprogramming—are already in clinical trials, which is very encouraging. The same goes for senolytics. And we’re also seeing progress in targeting telomeres (a compound structure at the end of a chromosome) to destroy cancer cells—the approach I originally proposed.”

Other areas, like removing amyloid build-up—the waste that accumulates between cells—are also being tested, though the benefits may become clearer when combined with other anti-ageing strategies.

Work on clearing waste inside cells has also advanced, particularly in diseases such as atherosclerosis (plaque buildup in arteries) and macular degeneration (an eye disease), though clinical applications are still a way off.

“That really leaves two big challenges,” de Grey said. “Fixing mitochondrial mutations and restoring elasticity to the extracellular matrix (network of proteins and other molecules that surround and support cells and tissues). Those are still tough problems. However, there are some promising new approaches.”

Strategic asset

Currently, the US leads with a hybrid ecosystem of federal grants, venture capital and philanthropic foundations. However, other major powers, including India, have also entered the race.

Europe’s funding remains smaller than that of the US, but it has a strong translational science base (from discoveries to real-world applications) and robust clinical research capacity. According to the Australian Strategic Policy Institute’s Critical Technology Tracker, China is the leader in areas like synthetic biology and biological manufacturing, which are foundational technologies for interventions that extend health span (number of years lived without disease) and lifespan. Notably, the ASPI says that China is likely to become a monopoly in synthetic biology, a field that focuses on redesigning biological systems—such as gene circuits, metabolic pathways and enzymes.

Those like de Grey believe there is no real distinction between extending health span and lifespan. “The only thing you need to remember about that distinction is that increasing lifespan is simply a side effect of increasing health span,” he says. Notably, this linkage—between health span and lifespan, and the relationship between disease burden and overall longevity, as well as national productivity—makes longevity a strategic issue for all countries.

The China Longevity Medicine and Anti-Aging Industry White Paper (2025) notes that the country’s focus is shifting from treating individual diseases to systematically intervening in the biological ageing process itself. The paper says that the Chinese prioritise intervention for those as young as 30 to extend health span. The country’s biotechnology sector is rapidly emerging as a global hub for longevity science, with state policy explicitly encouraging innovation in stem-cell therapy, gene editing, senolytics and tissue engineering.

India also launched a major national programme on ageing—the Longevity India Initiative of the Indian Institute of Science (IISc)—in April 2024. “The main aim is to understand what changes occur in the body as we age,” said Deepak Saini, convener of the initiative. “Routine blood tests fail to capture low-level dysfunction—they detect problems only when an organ has already deteriorated significantly. We need new biomarkers to detect early signs of dysfunction, and these must be studied in the Indian context because of our unique cultural, dietary and geographical factors.”

Earlier efforts like the Longitudinal Aging Study in India (LASI) have given valuable demographic data, but Saini noted that India now needs molecular-level data. “Within the next few years, we should have a much clearer understanding,” he said. “We started from scratch—there was no prior literature specific to India. We had to begin by identifying healthy individuals and studying them. That was the fundamental gap.”

Although the west has had a 25-year head-start, Saini insisted that India was not a late entrant. “Globally, everyone is at the same inflection point,” he said. “Unlike other fields where the west develops the technology and we adapt to it later, longevity science is still very new—even the west is still searching for answers. So, I don’t think India is left behind.”

Sajeev Nair, chief curator of the World Biohack Summit in Dubai and founder of health-tech firm Vieroots, said Indians are beginning to realise that by taking scientific control of their health, they can extend not just their lifespan, but also their health span.

Said Saini: “If people stay healthier for longer, the health care burden falls. Right now, our crowded hospitals reflect too many sick people. Improving health span would ease pressure on the system and benefit the economy.”

Notably, there was a sharp surge of interest in longevity in India in the latter half of 2025, fuelled by the country’s tech elite. Deepinder Goyal’s venture, Continue Research, and its still-mysterious product Temple—an experimental wearable linked to his “gravity ageing hypothesis”, which argues that gravity shortens lifespan—became central to the conversation. Critics dismissed the hypothesis as “pseudoscience”; but some saw value in the breadth of thinking and the willingness to leave no stone unturned in humanity’s quest for longevity.

Saini said that Indian companies are now emerging in ageing-related therapeutics and diagnostics. “The scale is smaller, but the momentum is the same,” he said. “Because India is a price-sensitive market, progress may be less visible—but it is happening.”

Disparity and democratisation

It was at the age of seven that American inventor and futurist Ray Kurzweil decided he would dedicate his life to invention. His mother was the first to believe in his ideas, however “fantastical” they seemed. As he grew up, Kurzweil went on to develop groundbreaking technologies—from speech-to-text software to the world’s first computer-controlled music synthesiser.

More remarkably, Kurzweil made nearly 150 predictions about technological advances, from the rise of the internet and smartphones to self-driving cars and AI-generated art. More than 80 per cent of these have come true.

Now 78, Kurzweil has a seemingly outrageous prediction—by the early 2030s, humans will reach longevity escape velocity. Ageing, he said, would become “optional”, with the help of human–AI integration and nanomedicine, in addition to biotechnology.

Another bold prediction is that by 2045, artificial intelligence will become superintelligent and merge with humanity, driving exponential progress. However, a key question remains: will this “progress” and “evolution” be limited to a select group of wealthy elites?

In November 2017, speaking at a cancer innovation event in Philadelphia, former Facebook president and philanthropist Sean Parker warned that growing wealth disparity could create a “class of immortal overlords”—the ultra-rich who might “live much longer, more productive lives” while the rest of the world is left behind.

“Because I’m a billionaire, I’m going to have access to better health care,” Parker said with a touch of self-loathing. “So I’m going to live to be, like, 160—and I’m going to be part of this class of immortal overlords. Give us billionaires an extra hundred years, and you’ll really see what wealth disparity looks like.”

It’s a fear many share—that the key to longevity might remain the privilege of a wealthy few, and that the compounding nature of wealth itself could deepen inequality.

Yet, others, like de Grey, remain optimistic that longevity technologies would ultimately democratise themselves. “For any technology,” he told THE WEEK, “how much it is restricted by ability to pay in the long run depends on how much people actually want it. Very few can afford a yacht—and nobody cares. But clean running water? Everyone has it.”

As with mobile phones, he said, once society recognises the transformative value of a technology, costs plummet and access expands. “If these therapies work—and if they have massive economic benefits because they eliminate the costs of keeping sick people alive—they will inevitably be made available,” said de Grey, “irrespective of the ability to pay.”