The biology of ageing, with Professor Claire Steves and Dr Carly Welch

Claire is Professor of Ageing and Health at King’s and a Consultant Geriatrician at Guy's and St Thomas' NHS Foundation Trust. At King’s, she leads the Centre for Ageing Resilience In a Changing Environment (CARICE), which aims to reduce the negative impact of the major colliding global challenges of climate change and population ageing. Carly, also a Consultant Geriatrician at Guy's and St Thomas', is a Clinical Senior Lecturer in Experimental Medicine at King’s. She’s interested in understanding the underlying ageing mechanisms that lead to impaired resilience in older adults and her research aims to translate new therapies into clinical populations to improve quality of life in older people.

Claire: So Carly, you're a geriatrician. Can you tell us what a geriatrician is?

Carly: That's a great question, and I think a lot of people misuse the term. Geriatrics refers to me as the doctor, and not to the patient as the word literally means doctor to an older person. So, when someone refers to the patient as a geriatric, they're misusing that term. As geriatricians, we provide healthcare for older people, predominately those living with frailty (increased vulnerability to illness) or multiple long-term conditions.

Claire: I'm a geriatrician as well, and I’ve noticed that increasingly, we are also turning our minds to how to use our medical understanding to help keep people well as they age. At the moment, while we're all living a lot longer, the reality is that many of us will end up living with long-term medical conditions which have impact on our lives. But how does it all happen? How do people become frail and vulnerable with the age? And can we change, reverse or maybe even stop any of these processes?

Carly: Older age is something we need to celebrate in society – those of us who are or who will be lucky enough to experience this time will reach this by living through our diverse lifetime experiences. However, as you said, we don’t all age in the same way. Ageing is not just one thing, but a combination of multiple processes happening to the body, and this doesn't just happen overnight – ageing happens because of lifelong exposure to lots of different factors. Some people can reach tremendous ages without having long-term health problems or functional limitations. We're really interested in understanding what is different about those individuals so that we can help people to stay in a condition of good health throughout their life.

At a biological level, there are multiple processes that change with age, and there's lots of ongoing research to see whether we can reprogramme what is happening in the body.

One example is cellular senescence. All the cells in our body go through a process of repair and cellular cycling, and this is normal for our health throughout life. But sometimes cells can become damaged, stop dividing and repairing, and enter a state called cellular senescence. This doesn’t just happen as we get older; it happens throughout the life course. But when we're younger, senescent cells are typically cleared by the immune system. As we get older, senescent cells can build up and the body can’t clear them as effectively. When they build up, they can get in the way of the other cells in the body.

There are drugs currently being trialled to see if they can remove senescent cells from the body, and that's very exciting because if we can remove those cells, it would leave more space for other cells to work.

Another important aspect of ageing is inflammation. This is when cells throughout our body release signals that interact and cause irritation in the body. Older people living with frailty or multiple long-term conditions tend to have higher levels of inflammation in the body. This is another exciting area of research for drugs, but also in terms of things that we can do for ourselves, for example we know that exercise can have a positive impact on inflammation.

Another hallmark of ageing is linked to the gut microbiome – the community of microorganisms that live in our gut that are vitally important in regulating our own body functions and processes. For some people who experience negative consequences of ageing, such as loss of physical function, strength and cognitive decline, these changes are associated with differences in the gut microbiome and the different types of microorganisms that live in the body.

Again, this is potentially something we can influence ourselves with simple changes to the diet. For example, increased fibre in the diet can help to promote healthy gut bacteria.

Claire: You mentioned that we all age differently, and different parts of our bodies might age in different ways. That's one of the reasons why, as clinicians, we try to tailor our approach to the individual to make sure we're delivering personalised medicine. We also have to think about how the body organs work together. When you're seeing your patients, Carly, do you often think about how the body systems interact in an older person?

Carly: Yes, definitely. Before the patient is seen by me, they may have been seen by multiple different health professionals. I run clinics where I see older people undergoing cancer treatment, and they have been seen by a cancer specialist who will have focused on the treatment of the cancer, and they may have been seen by a specialist in diabetes or heart disease. Each of those health specialists will have their own slant on what they're looking at. But what we do as geriatricians is to look at the whole picture together so that we can ensure they are receiving the treatment that is best for their health overall.

This could be something as simple as reducing the number of medications that someone is taking. For example, someone may be prescribed a drug for blood pressure and a second drug for prostate problems. But we can look at those together to see if there is just one drug that will treat both of those conditions.

Claire: What do you think the future looks like for our society in terms of ageing well? Will the focus be on prevention or on treatment? And at what point should we be thinking about changing things for ourselves?

Carly: I think we need to focus on prevention as well as on treatment. Like most things in health, prevention is better than cure. It's never too early nor too late to start thinking about what we can do to improve our health span. Simple things include physical exercise and eating healthy, well-balanced meals. From a muscle perspective, protein is very important for building and maintaining muscles (you can read more from Dr Olly Witard on this).

But even with the best health, people can develop illness. So, I think it's important that we have the best treatments to offer when people do become unwell. Being able to target ageing mechanisms would allow us to treat the root cause of many illnesses at once rather than treating illnesses within their silos.

I think for a lot of people, the idea of treating ageing sounds a bit like science fiction, but the more we understand about the biology of ageing, the more we can do to develop treatments to help people live healthier for longer.