Science can stop us ageing, according to a new book. But do we want it to?

I’m going to turn 40 this month, a milestone I’m approaching with nine-tenths equanimity, one-tenth mild existential dread.

On the one hand, with a kid and a job, I’m too busy to spend much time peering at my newly middle-aged navel. Plus, if you’re lucky enough to be healthy, griping about simply growing older is churlish. On the other, there is an undeniable psychic wrench in the realisation that I now tick the aged 40-60 box. Somehow, I seem to have lurched from young and clueless to the age where people will make jokes about the number of candles on my cake, without an intervening period of solid competence. I still run for the bus. I can still never find the lids for the Tupperware. I am older than the prime minister of Finland, but I can’t reliably pair my own socks. I don’t feel fully grown up, and yet there is the creeping sense that, as Sue Townsend put it via her timeless mouthpiece Adrian Mole, I’m on a “pathetic slide towards gum disease, wheelchair ramps and death”.

But is this slide inevitable? That’s the central question of Ageless: The New Science of Getting Older Without Getting Old, an ambitious and energetic new book by the scientist and writer Andrew Steele. While he’s not peddling some holy grail of immortality, he does give a startling round-up of the biological factors that make us age and the emerging techniques to tackle them, offering the prospect of both longer and healthier lives.

To start with some perspective: human lifespans vary hugely based on time and place, with life expectancy under the age of 40 the norm everywhere at the start of the 19th century, largely due to high child mortality. Drawing examples from the animal kingdom, Steele points out that innings vary from five minutes for a mayfly to 400 years for a Greenland shark. We are, of course, neither flies nor sharks. But if we accept the idea that a human life isn’t capped at 82 and pursue all the opportunities of frontier research, perhaps we could become more like tortoises. As Steele explains, the Galapagos tortoise, along with a handful of other blessed oddballs in the natural world, are “negligibly senescent” – meaning they “have no obvious impairments of movement or senses as they get older, and they experience no age-related declines in fertility”.

They don’t live forever. But referring to a giant tortoise discovered by Charles Darwin who lived until 2006, Steele writes: “Harriet was likely pretty much as sprightly at 170 as she was at 30, at the height of Queen Victoria’s reign – which is to say, not very; she was a giant tortoise, after all.”

This liveliness of tone helps to carry the reader through an unsparing account of the toll ageing takes on the human body. The comic writer Nora Ephron may have called her mature memoir I Feel Bad About My Neck, but ageing emerges from this book as less aesthetic challenge, more devastating, systemic collapse. The gloomiest statistic of the lot? Your chance of death doubles every eight years, as a range of processes make us progressively more susceptible to big killers like cancer, heart disease, stroke, dementia and diabetes.

Steele gives a jauntily accessible account of the mechanisms behind our decline. One overarching driver is “disposable soma theory”: the evolutionary logic that prioritises the health of our reproductive cells over the “soma” cells which make up our own bodies. I had always suspected that having a child somehow drained me of my life force: here is the evidence. And as our neglected soma cells age, things go wrong. Our telomeres, protective caps on our chromosomes which are essential for healthy cell division, get shorter. Autophagy – the process by which cells clear out their own junk – declines. Proteins misfold into sticky clumps that risk forming the plaques behind Alzheimer’s disease. Frail old cells linger: “They stick around, no longer dividing – aged, zombie cells which refuse to commit cell suicide, known as ‘senescent’ cells.” Our mitochondria – which give cells energy – misfunction. Stem cells falter. Chronic inflammation ups the risk of everything from diabetes to cancer. It’s a startling wake-up call that there are worse things bubbling away in your biology than a few grey hairs, or the frown lines that make every Zoom call of this pandemic a harrowing ordeal for the over-35s.

But what if there was another way? Don’t book your return trip to the moon for 2125 just yet. The science has a long way to go: as Steele points out, most of the research is in its early stages, bristling with the potential for pitfalls and unintended consequences. But there are a number of approaches that hold promise, with today’s huge advances in computing spurring new therapies. Steele posits that senolytics, or drugs that destroy senescent cells, could be with us in the next few years, albeit to tackle age-related conditions rather than ageing itself. After that, “more advanced treatments like gene and stem cell therapies could be available on timescales measured in decades”. Ultimately, instead of tackling the individual symptoms of ageing – a creaky knee here, a furred-up artery there – we will move towards “systems medicine” that stops us falling to bits in the first place:

“The first ageless generation probably won’t realise their luck at first – they’ll grow up expecting to die at 100, or 150, or whatever ‘old’ is for their society but, one after another, lifesaving medical breakthroughs will push their funerals further and further into the future.”

Steele writes with the maverick confidence of the outside perspective. He took a PhD in physics, then moved into computational biology before pursuing his interest in ageing as a writer. In this career switch, he has something in common with Aubrey de Grey, the bearded high priest of the anti-ageing movement who began with a background in computer science. While Steele stops short of making outlandish predictions – de Grey famously ruffled academic feathers with his claim people could live to be 1,000 – the logic is the same.

While we would all merrily jettison our wrinkles and give bowel cancer a miss, are we really ready for an ageless society, presuming the science stacks up? Steele writes quite reasonably that no one would invent the suffering of old age as a solution to an over-crowded world, but this research nonetheless opens up a fascinating Pandora’s box of challenges. Rather than a utopia of dewy-faced centenarians hover-boarding to work, we would probably first see a deepening of the grotesque inequalities that already exist in health today. There’s currently a nine-year gap in lifespans between the richest and poorest parts of the UK. Add some fancy preventive drugs to the mix and you can guess who would get them first. Moreover, with ageism rife in the workplace, especially in the tech industry which provides an increasing number of jobs, who could afford not to quaff the pills that keep you looking fresh in your hoodie?

Writing with the vim of a Bill Bryson and the technical knowledge of a scientist, Steele at least gives us a chance to grasp what’s at stake in this dazzling, daunting age where big data meets human biology. “Negligible senescence” may remain a stretch for my New Year’s resolutions, but I’d happily progress at a more tortoise-like pace towards the next milestones of decrepitude.