Dr Marina Ezcurra, Lecturer in the Biology of Ageing at the University of Kent, stresses the importance of innovative research focussed on understanding the fundamental processes underlying ageing
Ageing populations present massive socioeconomic and medical challenges. To address these, we must develop ways to promote age-related health. New research is generating interventions that target the biological processes underlying ageing and delay the onset of age-related diseases, increasing the time spent free of disease and disability.
Increased life expectancy has dramatic medical and socioeconomic effects Increased life expectancy and population ageing is occurring globally, a dramatic demographic change that will impact on almost all aspects of society. People aged over 65 are more likely to suffer from multimorbidity (suffering from multiple diseases), an overall decline of physiological functions and greater vulnerability to infections and fractures. Alongside physical conditions, mental health conditions such as depression and anxiety contribute to disability in late life. These diseases hugely strain healthcare systems and impact the quality of life of older people and families. The need to find strategies that promote healthy ageing is urgent.
Recently, governments and institutions such as the WHO have realised that ageing populations have dramatic effects on medical and social care, as well as wider socioeconomic effects on economic growth and equality. The COVID-19 pandemic has highlighted urgency of improving age-related health and the vulnerability that comes with an ageing population. So, what can be done to maintain health as we age?
Why do we age? Understanding the biology of ageing
An essential step towards improving the way we age is to understand ageing from a biological perspective. Research efforts over last few decades have resulted in deeper understanding of ageing and identified the biological processes driving ageing. We have learnt that ageing is a universal biological phenomenon resulting from dysregulation of core physiological processes. These core processes include how our bodies respond to nutrients (nutrient sensing pathways), the accumulation of cells that can no longer divide and perform their normal functions (senescent cells), changes in how genes are switched on and off (epigenetics), and the control of proteins (proteostasis), amongst others.
Dysregulation of these processes result in physiological decline, impaired functions and age-related diseases as we age. Work in laboratory animals shows that the dysregulation of the core processes can be delayed through pharmacological, environmental and dietary interventions, preventing disease and improving overall health. These findings suggest delaying ageing and age-related diseases is also possible in humans. More can be learnt from this area over time.
Developing interventions that target ageing
Traditional medical research is focused on diagnosing and treating age-related diseases individually and separately, without addressing underlying causes and multimorbidity. Change is needed here. By identifying and understanding the common, underlying biological mechanisms that drive ageing we can develop strategies that target the core ageing processes and prevent multiple age-related diseases. These strategies include drugs, dietary interventions, environmental interventions and health inequalities.
Currently, there are a handful of clinical trials of pharmacological and dietary interventions targeting ageing ongoing. For example, metformin, a drug used to treat type 2 diabetes is being tested for the prevention of several age-related diseases rather than a single disease. Another type of promising treatments are senolytics, drugs that kill senescent cells and reduce their accumulation. Senolytics are developing quickly and could be available in the U.S. relatively soon.
These recent developments are exciting, but more is needed. We need a detailed understanding the fundamental processes underlying ageing and how they relate to disease to design interventions. Candidate interventions identified in the laboratory need to be tested in clinical trials that evaluate effects on age-related multimorbidity in humans.
Moving forward: Research, funding and policy
The COVID-19 pandemic has exposed how poor health makes people more vulnerable to disease and how this impacts society. Moving in the right direction and increasing health and resilience during ageing, we must focus on three aspects:
Awareness of the problem is increasing among policy makers. The UK government has set the goal of adding an extra five years of healthy life expectancy for all by 2035 – but this is unachievable without a clear understanding of how we can extend time spent in health, combined with coordinated national policies. Concerted funding efforts are desperately needed for research on the biology of ageing and clinical trials. In this aspect the UK is far behind the U.S.; where there is dedicated research funding to study ageing and substantial commercial investment in ageing interventions. The UK has excellent facilities for research and drug development, and the potential to be a major global player in the development of treatments for ageing through ring-fenced funding and partnerships between academia and industry.
Further research on ageing combined with an understanding among policy makers of how lifestyle changes are best implemented, and an awareness about what can we do as individuals, families and communities to age healthier will be critical to address the challenges of our ageing population.