As human life expectancy has increased, so too has the burden of age-related diseases such as cancer,and . Consequently, research has focused on understanding and developing treatments for these individual diseases. While such efforts have improved management of these conditions and extended lifespan, they have not necessarily yielded corresponding improvements in healthspan. People now live longer, but accumulate morbidities at a similar rate, often suffering from multiple disabilities in their later years.
A more effective approach would be to address the root of the problem – the process of ageing itself. Finding ways to slow biological ageing in humans should delay the onset of age-related diseases. Furthermore, while chronic diseases have limited interaction, ageing is a fundamental system-wide process that increases risk for most chronic diseases, while also weakening the immune system and, consequently, the effectiveness of vaccination. Thus, a single intervention that slows ageing could have far greater impact than separate interventions targeting different chronic diseases.
Over the past decade, we have begun to see translation of some anti-ageing approaches from the lab into clinical trials, however, the effectiveness of these interventions can be hard to assess because age-related diseases progress over decades. This is why biomarkers of ageing are important. A biomarker of ageing is a process that can be measured in order to gauge the true biological age of a cell, such as changes in DNA methylation patterns. This allows researchers to assess the impact of an intervention on the rate of biological ageing, without the need for very long studies. Identifying practical and accurate biomarkers of ageing is an ongoing field of research.
The focus on treating individual age-related conditions as opposed to the ageing process itself continues to be relevant when it comes to the COVID-19 pandemic. In this article, American Ageing Association president Professor Matt.R Kaeberlein warns that when it comes to allocating resources to protect the population against Covid and future pandemics, we may be missing the most obvious and effective approach. We have known since the beginning of the pandemic that Covid disproportionately affects the elderly, with the majority of deaths occurring in those over 65.
Several explanations have been offered for this increased susceptibility, including chronic health conditions, a weakened immune system, and increased frailty. These conditions have a common underlying cause: the biological process of ageing itself, yet ageing is not being seriously considered as a target for COVID-19 prevention.
Consider as a simple thought experiment the impact of a treatment for immune aging that causes the immune system of a typical 70 year-old to function as it did when that person was 50. Current data suggest that risk of dying from COVID-19 increases approximately 10-fold for every 20 years of age. So, we could expect a 90 percent reduction in lethality from such an intervention. Suddenly, a global pandemic that has wrought generational economic and social devastation becomes a mild flu season.
Consider further that much of our current hope for a return to normalcy rests on the development of a COVID-19 vaccine. Assuming this is accomplished, it may provide effective immunity in younger people but will still not work well in the vulnerable older population. We should not fool ourselves into thinking that a COVID-19 vaccine will be a cure, unless we also find a way to boost immunity in the elderly, allowing them to develop an appropriate response to the vaccine.
As Prof. Kaeberlein points out, it is not that we lack therapies that could potentially protect against multiple age-related diseases or rejuvenate the immune system, but that these possibilities are not being adequately explored. Instead, resources continue to be directed towards ‘largely futile’ efforts to treat individual diseases.
Healthy aging: The ultimate preventative medicine: DOI: 10.1126/science.aad3267
Chapter 19 - On the Compression of Morbidity: From 1980 to 2015 and Beyond: https://doi.org/10.1016/B978-0-12-411596-5.00019-8
COVID-19: Why it kills the elderly and what we should do about it: https://thehill.com/opinion/healthcare/498069-covid-19-why-it-kills-the-elderly-and-what-we-should-do-about-it
TORC1 Inhibition Enhances Immune Function and Reduces Infections in the Elderly: DOI: 10.1126/scitranslmed.aaq1564