Increased longevity is a triumph of modern medicine and health systems. In the UK, life expectancy has risen by about 25 years in a century – from 56 for men and 59 for women in 1920, to 80 and 83 in 2019 (since when it has slightly fallen back). While this extension is often taken for granted, rising interest in the science of ageing reveals an awareness of the challenges as well as the benefits that getting old, and being old for longer, can bring.
Last week, a paper in the journal Nature Aging offered evidence that humans do not age steadily, but in bursts. Molecules and microbes in samples from participants showed that big changes occurred in their mid-40s and early 60s. One example from the 40s was a reduced capacity to metabolise alcohol – a finding that will come as no surprise to middle-aged people who have cut down on drinking, after finding it no longer agrees with them.
Headline figures mask deeply concerning inequalities between the average lifespans of wealthy and socioeconomically deprived groups, which are also reflected geographically. Over the last decade the north-south divide in longevity in England has grown. Global disparities are even starker, with wars and violence cutting thousands of lives short, and high infant and child mortality rates holding down average lifespans. But rising longevity is a global trend and not one limited to wealthy western countries.
Since most people want to live until they are old, this shift is hugely welcome. For scientists of ageing, we are living through what Prof Richard Faragher calls an “extremely hopeful time”. Knowledge of the biological processes of ageing has increased dramatically, with new discoveries about stem cells and telomeres – which protect the ends of chromosomes and shrink over time.
But demographic change also means new human needs and pressures. Some of those associated with an ageing population are well known. In the UK, strain on the social care system that supports older and disabled people is widely recognised, although recognition has yet to result in the policy shift, and democratically negotiated funding settlement, that are needed to ensure all can access the care they need, with risks pooled so that an unlucky minority do not end up losing their life savings. Gaps in the current system mean that older people without relatives to help look after them are particularly, and sometimes painfully, exposed.
Ever since humans gained awareness of mortality, they have sought to cheat death and extend life indefinitely. In a recent Guardian podcast Venki Ramakrishnan, the Nobel prize‑winning chemist, compared cryogenics with mummification as practised by the pharaohs. Short of defying death altogether, the holy grail of ageing research, and the self-help industry that coexists with it, is “compression of morbidity” – which means a reduction in the proportion of life spent in poor health.
The jury is out on the extent to which this is possible. What ought to be encouraging, however, both for ordinary people trying to live their best lives, and for governments whose job is to make this easier, is that Prof Ramakrishnan and others believe the trio of a healthy diet, regular exercise and adequate rest are “better than any anti-ageing medication on the market”. Eat (but not too much); run (or find another way to stay active); sleep.
