In the past century, developed countries have witnessed a remarkable increase in life expectancy, with people now living up to 30 years longer than their counterparts a century ago.
Advances in medicine, such as vaccines, sanitation, and antibiotics, have played a significant role in reducing mortality rates from infectious diseases. However, this increase in longevity has given rise to a new challenge: healthspan, the period of life free from chronic diseases or disabilities, does not always match the extended lifespan.
According to the World Health Organization’s healthy life expectancy indicator, a person who expects to live to 79 may face serious disease as early as 63, leaving them with 15 years (20 per cent of their life) lived in sickness. Ageing itself is the biggest risk factor for major diseases like cancer, heart disease, and dementia. While medical research and clinical practice have traditionally focused on treating individual diseases to extend lives, a new approach based on the biology of ageing is gaining momentum.
Geroscience, a field dedicated to studying the biology of ageing, recognizes the importance of extending not just lifespan but also healthspan. Researchers now emphasize that slowing down the ageing process is key to achieving this goal. Various molecular and cellular processes occurring within our tissues and organs determine both our lifespan and healthspan. These processes, known as the “pillars of ageing,” include DNA damage, cellular senescence (ageing), inflammation, and stress responses.
While environmental factors contribute to natural variations in these ageing processes, genetics also play a significant role. Approximately 25 per cent of the variability in ageing can be attributed to genes, with extreme cases demonstrating even higher genetic influence. This means that some individuals age faster than others, leading to increased susceptibility to diseases and disabilities.
Assessing biological age has become an area of interest for researchers. Biologist suggests that molecular markers, such as chemical modifications to DNA, can provide insights into an individual’s biological age. By examining the patterns of chemical tags on cells, researchers can compare them to those typically found in individuals of different ages, such as 20, 30, or 40 years old.
While geroscientists have yet to develop a pill or treatment that can effectively slow down or reverse the ageing process, they are exploring promising avenues. One such approach involves targeting senescent cells, which are cells that no longer divide but instead accumulate in the body due to immune system clearance failure. These “zombie cells” secrete proteins that can interfere with the health of surrounding cells and have been associated with conditions like osteoarthritis, cancer, and dementia.
In a groundbreaking 2015 study conducted on mice, researchers successfully used senolytic drugs to remove senescent cells and observed delayed, prevented, or alleviated multiple disorders. While clinical trials are underway in humans, it will take several more years before conclusive results are obtained. Researchers caution against falling for unverified claims about “prolonging youth” through popular wellness practices until solid evidence is available.
In the absence of a definitive solution to slow down ageing, focusing on preventive maintenance is crucial for extending healthspan. Experts recommend regular checkups to monitor cholesterol levels and blood pressure. Guidelines from the American Journal of Clinical Nutrition regarding body fat percentage, lean body mass, and bone density should also be followed. Awareness of one’s overall health status allows individuals to make necessary adjustments to maintain optimal health.
The four main factors for extending healthspan are common sense but often overlooked: nutrition, sleep, exercise, and social connection. These lifestyle choices play a significant role in modulating the biology of ageing. For instance, engaging in regular low- or moderate-intensity exercise can help prevent cardiovascular disease and type 2 diabetes. Experts suggest that by implementing these steps consistently, individuals may potentially add ten years of healthy living to their lives.
While significant progress has been made in understanding the biology of ageing and its impact on healthspan, there is still much work to be done. The goal of extending both lifespan and healthspan remains a priority for researchers and medical professionals alike. By unravelling the intricacies of ageing processes and developing targeted interventions, we may soon witness breakthroughs that enable individuals to live longer, healthier lives free from debilitating diseases.
