After a year in which there was only really one headline in the health news – indeed, only one headline in the news overall – it might seem like a strange time to be launching a book which makes the case that ageing is our greatest challenge when it comes to human health.
But the pandemic has only emphasised the urgency of the case. As we hopefully get coronavirus under control during 2021, it’s time to look to a brighter future – and the fascinating anti-ageing science which is going to help us get there.
We first need to understand what ageing is, from the perspective of a biologist. A simple definition is to look at how our risk of death varies depending on how old we are. Coronavirus provides a timely case study: your risk of death if you catch Covid doubles every six years or so, starting out rather modest in children or young adults, but eventually climbing incredibly rapidly to maybe five per cent or 10 per cent in over-85s.
Overall, our risk of death doubles about every eight years as we get older
The fundamental reason older people are at greater risk from coronavirus is because of changes in biology as we age. As we age, our bodies slowly move from a state of relative order, to one which is chaotic and disordered. This affects everything from our DNA up. Of particular relevance to Covid, our immune systems weaken in their response to external threats. This is at the same time as developing a paradoxical hyperactive, destructive streak towards our own bodies.
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This is reflected in our risk of death from other causes too. Our fraying DNA can result in a cell acquiring the mutations needed to turn into a cancer, while our distracted immune system is less able to spot the nascent tumour, allowing it to flourish. Other big killers of modern times like heart disease, stroke, dementia and so on can all be chalked up to the complex interactions of the various ways our bodies deteriorate on the cellular and molecular level as we age. Overall, our risk of death doubles about every eight years as we get older. This is strikingly similar to our risk from the threat of coronavirus.
Our current approach to medicine tackles these ailments one at a time – chemotherapy for cancer, operations for heart disease, a stint in intensive care for severe Covid – but ignores the root cause: the ageing process itself.
Viewed like this, I think that ageing is our greatest humanitarian challenge. Global life expectancy is now comfortably over 70, meaning that most people in most countries live long enough to suffer from the diseases of ageing. As a result, it is responsible for more than two thirds of deaths globally, and years or decades of suffering for billions of people around the world.
This isn’t science-fiction. Drugs called senolytics, which make mice live longer and in better health, are already in human trials
So, what can we do? Experiments in the lab are showing us that this exponential risk of death, cancer and coronavirus need not be inevitable. We now have dozens of ways to slow down ageing in everything from cells to lab animals. By changing their diets, altering their genes, or giving them anti-ageing drugs we can make mice live longer. And, crucially, have them live healthier lives.
Imagine if, instead of an older person getting cancer and then us trying to treat it with exhausting rounds of chemotherapy, in a body also suffering from the early stages of heart disease and dementia, we could give them preventative anti-ageing treatments decades earlier which would slow their decline with age, and stop them getting cancer in the first place.
And this wouldn’t just reduce the risk of cancer or dementia. Mice on anti-ageing drugs in the lab are also more curious, and even have better fur. This is because the same processes behind diseases are also behind our cognitive and cosmetic decline with age. We would look younger on the outside as a beneficial side effect of being younger and healthier on the inside.
Did you know that watching this video is more fun that whatever you’re doing right now?
— Andrew Steele (@statto) January 10, 2021
This isn’t science-fiction. Senolytics, drugs which remove aged cells and make mice live longer and in better health, are already in human trials. They are being trialled for age-related problems like arthritis and chronic kidney disease. If they work and prove safe, it might not be long before we’re taking them to optimise our old age.
These treatments could reduce our risk of many diseases, from heart disease to dementia, all at once. They could also reduce changes we don’t label as diseases, from frailty to wrinkles. And, while vaccines will hopefully be the endgame for Covid-19, real anti-ageing drugs could strengthen our immune systems in readiness for the next pandemic.
Science will turn the tide on coronavirus, developing effective vaccines for an entirely new disease being in months. If we could turn the same high-tech tools of modern biomedical research to ageing, and with similar tenacity, 2021 could see some altogether more optimistic headlines on the health pages.
Ageless: The New Science of Getting Older Without Getting Old by Andrew Steele is out now (Bloomsbury, £20)