Holding back the years: the new science of ageing
It is hugely neglected as a field of research – yet it could hold the key to preventing numerous killer diseases as we get older, writes Andrew Steele
Ichanged career because of a graph. That’s a slight oversimplification, but it’s not much of one. The graph in question is how our risk of death changes with age, and it’s both terrifying and fascinating. We all know that older people are more likely to die – but quite how much more likely is shocking. I’m in my 30s, which means my odds of death are somewhere around one in 1,000 per year. If I’m lucky enough to live to 90, my odds of not making 91 will be a rather more sobering one in six.
At the time I saw it, I was nearing the end of a PhD in physics. But it wasn’t mortal terror that meant this graph compelled me to switch fields. The fact that our risk of death doubles every eight years, meaning we go from nearcertainty of survival to potentially being denied our next birthday at the roll of a dice, suggests that there is some underlying biological process driving this exponential increase.
When you die, you have to die of something. The reason 85-year-olds die more often than 35-year- olds is that they’re at vastly greater risk of diseases, from cancer to dementia. And the reason we become more susceptible to diseases must lie in changes in our biology. And if we could understand those changes, we could come up with treatments to slow their onset, reducing the risk of all of these diseases at once.
This is what’s fascinating about this graph – not what it directly represents in terms of risk of death, but the hope that understanding the biology underlying it could help us create preventive medicines for the world’s leading killers – cancer, heart disease, stroke, dementia and so on.
We still need a second piece of evidence before this graph becomes truly compelling, rather than merely scientifically interesting: we need to know that science can do something about these age-related changes to our biology. And the exciting fact is, we do. Scientists now have dozens of ways to slow or even reverse the ageing process, in everything from cells to whole animals – and some of these ideas are beginning tentative human trials. From changing their diets, to altering their genes, to giving them drugs which specifically kill aged “senescent” cells, scientists can make mice live longer and, crucially, healthier lives.
These mice defer death, diseases, slow their cognitive ageing and even look strikingly better than their untreated counterparts, with plumper skin and thick, glossy fur. Real antiageing treatments would slow the cosmetic signs of ageing at the same time as they repaired the chaos in our cells. We’re very keen to alleviate these changes, as shown by the huge market for skin creams and hair dye – and we’d get these cosmetic improvements for free, as a side- effect of treatments which will extend the time we spend healthy, because wrinkles and grey hair are caused by the exact same biological mechanisms that predispose us to cancer and heart problems.
But in spite of this, and the exciting science that shows it’s possible, ageing biology is incredibly neglected as a field of research. Most medical research concentrates on specific diseases, trying to come up with new treatments for cancer or heart disease, but neglects the physical process that causes almost all of them: ageing itself. In the US, ageing biology receives about 20 times less government funding than cancer research – and less than one 10,000th of what Americans spend on healthcare, even though the chronic diseases of ageing are responsible for a huge fraction of healthcare costs.
This is what compelled me to switch from physics to biology. I’m someone who’s very much driven by numbers: seeing these statistics was enough to convince me to change fields. It’s perhaps not a total coincidence that it happened as my parents entered their 60s and – while they keep fit and have mercifully dodged any serious health issues so far – are beginning to show signs that they aren’t as young as they used to be.
I’ve since had my indirect experience significantly broadened by marrying a doctor who, as she rotated through different hospital wards, saw the many different impacts that ageing can have on every part of our bodies, and lives. Those of us without a medical background might visualise finding a lump, having a scan, going through the ordeal of cancer treatment, and hopefully getting better. The reality is far, far messier. Most cancer patients are older people who have multiple conditions vying to incapacitate them, and are taking a laundry list of drugs, all of which complicate their treatment, or even make them ineligible for certain procedures. The fundamental reason is that they were born a long time ago – but there’s nothing my wife can do to treat that. At least, not yet.
In a year when the health news – indeed, all news – has been dominated by coronavirus, it might seem counterintuitive to want to focus on ageing. But Covid actually makes the case for treating ageing even stronger: age is by far the greatest risk factor if you catch Covid and, if we could rejuvenate the immune systems of older coronavirus patients, effectively making them biologically younger, their risk of death could be dramatically reduced. It’s likely that the vaccines now being deployed will be our saviour in this pan
A population with ‘younger’ immune systems would prepare us for the next pandemic
demic – but working towards a population with biologically younger immune systems would make us much better prepared for the next one.
This, fundamentally, is why we need to focus on ageing research: from cancer to coronavirus, older people are much more susceptible because of their biology. And this is exciting right now because of the pace at which ageing biology is moving, even in spite of its neglectedness. There are now more than two dozen biotech start-ups working on removing one particular agerelated biological change – those aged, senescent cells I mentioned – from our bodies. At first, this will be to treat specific diseases where these cells are known to be a problem, from arthritis to lung fibrosis – but, as these first trials teach us how to remove senescent cells safely, it’s not at all inconceivable that they could be used more generally, to slow down the ageing process for us all.
My book, Ageless: The New Science of Getting Older Without Getting Old, looks at the rapid progress against 10 “hallmarks” of the ageing process, of which senescent cells are one. If we can translate the ideas to treat all 10 of these from the lab and into the clinic, we could slow down our biological descent into decrepitude and, with it, the massively increased risk of disease we all face as we get older.
Among other things, 2020 has shown us that what impacts on our health can turn our lives upside- down, transform our economies and upend our politics. It’s also shown us that the ultimate answer to challenges in health is science, with vaccines being developed in record time. If we could make 2021 the year in which we choose to pursue ageing biology with even a fraction of the tenacity with which we’re tackling coronavirus, it could be the start of a biomedical revolution.