Every time we extend lifespan, we also extend healthspan. Whether we are studying the effects of dietary restriction in rats, ‘senolytic’ drugs that kill senescent cells in mice, or we are examining the genes of 150-day-old worms or 100-year-old people to learn the secrets of longevity hidden in their DNA, we typically find that their extra years of life are in good health. There’s some evidence suggesting that knowing this fact could make a significant difference in people’s opinions: another study asked how long respondents would want to live if guaranteed physical and mental health— 80% said 120 or longer, and almost half hoped for an indefinite lifespan under such circumstances. 

It’s worth bearing in mind that any changes in lifespan will happen very slowly. Even if we cured ageing next week, we wouldn’t have many 200-year-olds walking around for at least another century, simply because it will take our current oldest people 100 years to get there. Even in the most extreme scenario of a cure being developed and rolled out globally in an instant, we’ll still have plenty of time to adapt to any new normal. In a more plausible, gradual scenario, the challenges of increasing life expectancy will move slowly enough that we’ll have plenty of time to get ahead of them.

Overpopulation suggests that our concern is too many people, when actually the issue is the amount of resources we use. Already at current population levels we’re putting huge pressure on the climate, land, water and ecosystems.
Response is that addressing this is something we desperately need to do any way as soon as possible.

The UN’s ‘medium variant’ prediction estimates that global population will be 9.8 billion in 2050. Let’s imagine a complete cure of ageing, by 2025. In this ‘worst’ case, the population in 2050 would be 11.3 billion—16% larger than had we not defeated ageing.
A study considering a more realistic scenario, that ageing could be cured by 2040, found that the population would be just over ten billion in 2050, and 14.8 billion in 2100.

There is a far less cruel method to curb human numbers than letting people die of old age—reducing birth rates. This is something which is already happening naturally, thanks to what’s known as the demographic transition: a global shift from high birth and death rates to both being low. As death rates fall, especially child mortality, women tend to have fewer children.The same thing will happen as people live longer and healthier lives.

Take the concern that a booming population would put stress on our ecosystem. Would we create ageing, and condemn billions of people to decades of frailty and decline, to reduce our impact on the planet? Similarly, would causing 100,000 deaths a day (the current global toll of the ageing process) be a proportionate response to end the potential tyranny of an immortal dictator or to alle viate unequal access to anti-ageing treatments? I think, examined this way around, the answer in each case is clearly not—and that means that the reverse, arguing to maintain ageing to perhaps alleviate these issues, is equally clearly the wrong approach. 

It is known for certain that even biologically immortal creatures ultimately die.
There will still be buses to be hit by, infectious diseases, and even things like cancer and heart attacks, just at much lower rates than today.

People may want to leave a legacy—a body of work, a happy family, a successful company or a life well-lived—but you don’t need to die to do those things. It’s not even obvious that death is an intrinsic motivator to succeed at them. When you last went for a promotion, asked someone out on a date, or did a good deed, did you do so because you knew that death was bearing down on you several decades hence? The idea that death gives life meaning sounds poetic, but it doesn’t stand up to scrutiny. 

Whether it’s Alzheimer’s research or finding new ways to combat malaria, most biomedical science aims to make people healthier, usually with the side effect of longer lives. The goals of biology of ageing are no different. ‘Curing ageing’ sounds weird at first, but we’re already living longer, healthier lives thanks to improving lifestyles and advances in medicine—anti-ageing treatments would just be an extension of progress already underway.

The current cost of dementia, which includes health and social care, plus indirect costs of the sufferers being forced to give up work, or friends and relatives reducing their working hours to help take care of them, is estimated to be over $1 trillion worldwide, rising to $2 trillion by 2030. And dementia is just one of dozens of age-related conditions. Alleviating even a fraction of the economic burden of these diseases would free up tens or hundreds of billions of dollars a year to cover the cost of the anti-ageing treatments that helped eliminate them. 

In high-income countries, life expectancy averages 81 years, and spending on health care averages over $5000 per person per year. Globally, most people live in middle income countries, which have an average life expectancy of 72—but an average GDP per capita of…$5000 per year. Healthcare at the level familiar in rich nations is, there fore, obviously untenable. This is an oversimplification (for example, labour costs are lower in poorer countries, which means doctors and nurses are cheaper), but it gives a sense of the scale of the problem: it will take decades of economic growth to solve it the old-fashioned way. Even more so than the rich world, poorer nations could benefit from treatments for ageing to avert a looming crisis in their healthcare systems—and it will be the moral duty of the rich world to ensure universal access.

Headline life expectancies of 80-plus years in the rich world mask huge vari ations between regions within those countries, driven in large part by socioeconomic factors. While the interaction between poverty and health is incredibly complex, the end result from a biological perspective is that the less wealthy essentially age faster than the better-off. Higher rates of smoking, alcohol consumption, obesity, inactivity and so on, driven by a constellation of social factors, cause the same biological changes as accelerated ageing. This means that ensuring wide access to treatments for ageing would be a valuable adjunct to other policies aimed at reducing inequality. 

First off, it’s quite normal for all kinds of goods to be used by rich people in rich countries before being accessible globally. This is already true of medicines from basic vaccines and antibiotics to cutting-edge cancer drugs: while the former are now available in most parts of the world, expensive new treatments for cancer are unlikely to be found in clinics in the developing world any time soon. There is good reason to campaign for wider access to advanced treatments and to pursue research into neglected health problems which are particularly found in poorer countries—but bashing biogerontology doesn’t advance either agenda.

There’s also a reasonable case to be made that tackling ageing medically could help the world’s poorest. Global life expectancy is over 70 years, which means that most people in most countries will grow old enough to experience the diseases and dysfunctions of old age. Over half of dementia sufferers live in low- or middle-income countries—a figure that is projected to increase to two thirds by 2050, totalling 90 million people. And again, these are the figures for just one age-related disease.

Curing ageing would change and vastly improve what it means to be human. But, once it’s cured, preventative anti-ageing medicine will seem as familiar as cars, computers and air travel do now, and it will be just as hard to imagine a world before it. The annual check-up with our gerontologist will be as normal as a visit to the dentist; we’ll wash down healthspan-enhancing pills and supplements with a gulp of morning coffee; a once-a-decade hospital stay for a stem cell infusion will seem serious but routine, more like giving birth than open-heart surgery. 

There are also reasons to believe that curing ageing would make society better in less direct ways, like helping all of us value life itself more than we do at present.

If we lived 200 years, what are currently leading causes of death in youth would become the leading causes of death overall. Helping people at risk of suicide and preventing road accidents would take on a new importance: if dying in a car crash at 30 would rob someone of 170 years of life, that would provide a strong incentive to improve vehicle safety, or to encourage people into safer forms of transport. War and murder, too, would become even less tolerable than today as their cost in years of healthy life exploded. This new actuarial calculus could mean the world becomes an ever-safer and more pleasant place to live. 

These worries enter the realm of pure speculation—the absence of any 200-year-olds to ask means that we simply can’t know whether you’d be crushed under the weight of two centuries’ worth of wisdom and memories.
There are already far more interesting and joyful experiences available on Earth—places to visit, books to read, music to listen to, people to meet—than it is possible to conceive of, let alone actually do in a current lifespan. There are nearly 200 countries in the world—even visiting two a year, you’d be lucky to squeeze them all in. And that assumes that humanity and technology will stand still: what incredible multisensory experiences might brain– computer interfaces enable in the year 2300? How much fun will there be to be had exploring the moons of Jupiter? Unless you somehow get bored with the very essence of being alive itself, it’s hard to imagine running out of stuff to do, even if you lived for centuries. 

There’s no way any one would stick with the same career for 150 years, for example; it’s quite likely that the job you started after university wouldn’t exist a century later. Someone living 100 years (if we don’t make significant head way against ageing) might expect a 60-year career, bookended by 20 years of training, and 20 of retirement. There are also obvious issues with the existing model of pensions and saving for retirement: retiring at 65 or even 80 might be economically untenable if people routinely retire for as long again. If we could live for 150 or 200 years, it’s hard not to imagine a cyclical process interleaving work, retraining and peri ods of temporary retirement. 

Of course, the answer is that, technically, yes, they could. How ever, the data suggest that this wouldn’t be as much of a problem as it sounds. If you look at causes of death for dictators, they are one of a handful of groups for whom ageing doesn’t top the list. Far more common is being killed by a peer who fancies the top job, or dying in a military coup. In fact, one calculation suggested that completely curing ageing would only add 3.6 years to a dictator’s life expectancy. Aspiring autocrats in a post-ageing world would be well advised to seek a safer line of work. 

Is it the case, as physicist Max Planck once quipped, that science makes progress funeral by funeral? Do new ideas (and perhaps not just in science) ultimately triumph not by convincing the old guard, but by allowing them to die off and be replaced by a new guard unfettered by old ways of thinking?
Sociologists and economists have tried to establish whether deaths really do catalyse scientific progress, with mixed results.
If indeed this is a problem, in science or more broadly, the most obvious solution is term limits.

Worrying about immortal dictators is also a classic example of concentrating on the negative consequences over the positive: why do we focus on despots, rather than on great leaders or artists who could inspire more people for longer, perhaps with even greater works thanks to their additional accumulated experience? What about scientists uncovering new truths about the universe that only become accessible after 100 years mastering their craft? Since there are far more creative people than tyrannical leaders, an ageless society would very likely be far better on balance—and we’d all be around much longer to enjoy it.