TODAY, a child born in the has a greater than 50 per cent chance of living into their nineties. That is a remarkable testimony to medical, scientific and social progress, which has lowered mortality rates so we die later. It is a widespread trend: global life expectancy now exceeds 70, up from about 47 in 1950.
It seems that one longevity revolution is coming to an end. For the first time in human history, the most important health challenge is to age well. So begins a second longevity revolution – one focused on changing how we age, and slowing the ageing process so that lives aren’t just longer but also healthier for longer. But this will require a transformation in our health system, careers and pensions as well as cultural norms and individual psychology. It also demands a shift in scientific focus away from individual diseases and towards a greater understanding of the biology of ageing.
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Increasing life expectancy has changed the global burden of disease. The now include cardiovascular disease, pulmonary disease, dementia and diabetes. All of these have a common risk factor: age. If we could find a way to slow down biological ageing, we could potentially impact multiple diseases. This would unleash enormous welfare gains, with one study estimating that a one-year gain in life expectancy in the US would be worth around .
But achieving this requires changing how we think about ageing. It means accepting that the biology of ageing is a mainstream line of scientific inquiry, not a throwback to alchemy and promises of immortality.
Evidence that change is occurring is accumulating. Consensus is building around the of ageing, and researchers are making progress on pinning down how some of these pathways work, for instance in areas of . There are now methods for . With a proliferation of journals focused on ageing, and billion-dollar funding flowing into geroscience, change feels firmly underway.
This shift also requires recognising that ageing is malleable, not inevitable or fixed. We too often draw a distinction between health and the consequences of ageing, assuming the latter are natural phenomena. That thinking reflects past success in treating diseases such as smallpox or typhus. For most of history, those were also seen as natural and inevitable. But no longer. We now need to translate that progress to tackling how we age – and remember the words of French philosopher Michel de Montaigne that “to die of old age is a death rare, extraordinary, and singular, and therefore so much less natural than the others”.
A focus on ageing and ageing-related diseases also ushers in something unique – a virtuous circle that other diseases don’t possess. When progress was made in treating infant diseases, infant deaths fell, so research moved on to the diseases of middle age. Breakthroughs there led to fewer midlife deaths, and so science shifted to focus on ageing-related diseases. But the better we get at ageing, the more older people there will be and the more valuable further gains will be. When we are ill in our 90s, living into our 100s has little appeal. But if we can be healthy 90-year-olds, then we want to live for even longer. A second longevity revolution focused on changing how we age thus opens up the possibility of living to ages far greater than ever before.
Where we end up depends on a battle between human ingenuity and human biology. But in a world where the young can expect to become very old, a longevity imperative sets a course for a new scientific terrain, and a dramatic change in how we live our lives.
Andrew Scott is professor of economics at London Business School and author of The Longevity Imperative
