Age is just a number….or is it?

There is no certainty in the world, they say, except taxes, and death. Yet, that has not stopped people from trying to escape both. There is no dearth of tax avoidance, fraud and related litigation - tax ‘advisory’ and law are fields brimming with activity and make for lucrative careers too! 

What about death though? There has indeed been a constant striving in medicine and science towards increasing lifespan. At the most fundamental level, there is much to cheer about. The last century has seen a significant increase in life expectancy due to a reduction in infant mortality, vaccines and antibiotics. This has helped tremendously by reducing the probability of death before old age. However, treating diseases related to old age and ‘senescence’ has proved far less tractable. Modern medicine has found ways to treat heart ailments once discovered - but cardiac diseases are still among the largest killers globally. Similarly, cancer has proved a holy grail, though many drugs have been able to ‘manage’ the disease better. 

Significantly, there is a large difference between lifespan and health-span. While a lot of research has focused on extending life itself, the same may not be said about health-span. The challenge before us to help people live healthier lives in their final years, rather than under constant medical care.

So what do we really know about ageing, and how it can be delayed? There are many theories and almost none of them have incontrovertible evidence to back them up. One of the most prominent theories is that ageing involves the process of damage to our DNA. This damage, it would seem, prevents the reproduction of healthy cells in the body and therefore causes ageing. One of the suspected methods of reducing DNA damage is caloric restriction - a lower intake of food and periodic starvation is believed to produce DNA repair and therefore a delay in ageing. This, of course, is easier said than done and the degree of caloric restriction that is needed to prevent or reverse ageing could well be severely inconvenient and unacceptable to humans.

Second, is the role of ‘senescent cells’ in the human body. This theory postulates that as we age, there are some cells in the human body that get stressed and decide to opt out of the cycle of cell division. Not only do they count themselves out, but also secrete a certain substance that accelerates the senescence of other cells in the human body, leading to ageing diseases such as osteoarthritis, cancer and atherosclerosis. As per some studies, each cell in the human body is limited to 50 cell division cycles. However, we now hear about a new class of drugs - senolytics, that are being tested for their ability to disrupt these senescent cells and prevent the ageing process.

One of the most popular explanations of ageing is oxidative stress. This is a process that causes damage to tissues through the accumulation of chemicals called ROS (Oxygen reactive species) in the body. There is a related issue called inflammation which is caused by oxidative stress. Many of our ageing related diseases including cancer are also suspected to be caused by chronic inflammation. What causes oxidative stress? While no one knows for sure, the usual suspects are pollutants, smoking, and high sugar-containing foods. On the other end of the spectrum are the anti-oxidants and foods with supposed anti-inflammatory properties - berries, turmeric and green tea to name some ‘super-foods’. Consumption of these are possibly linked to the reversal of oxidative stress and ageing.

The larger question is this - can humans manage ageing better, if not stall it completely? There are significant implications here - not just scientific, but also social (think demographics and polity) as well as economic (think healthcare costs, government finances and pension systems). As individuals - what perhaps matters most are the takeaways for healthy living - not just longer lifespans but longer health-spans. What started as a quest for immortality and the Elixir of life must get down to more mundane questions of diet, biology and lifestyle - the devil always lies in the details!