Rhishav Narayan Choudhury
What would a world without death be like? Would all our philosophical and religious belief systems about god and the afterlife crumble, and our traditional reproductive and procreative days come to an end? Does life have more meaning because our time is limited, and will immortality be the burden described in Gulliver’s Travels where a few of the Luggnaggians never died, or would a legion of immortals contentedly inhabit our world?
“I don’t want to achieve immortality through my work. I want to achieve it through not dying.”
— Woody Allen, American film actor and director.
It is said that death is the only inevitability in life. Numerous civilizations have grappled with the meaning of death and have built extensive philosophical and religious belief systems to cling on to the notion of an existence beyond death. But imagine, for a moment, a world in which humankind managed to evade the one certainty that greets us at birth and unites us all, regardless of who we are and what we believe. Envision a life without death! From the fountain of youth to the sorcerer’s stone, our minds have long wandered into just such a territory. As preposterous as such a world might sound, it might not be as far-fetched as you might expect.
Let’s begin by asking ourselves: Why do we die? Death is the moment we take our last breath. Lack of oxygen entering our lungs, to be used by cells to carry out the metabolic functions needed to support life and generate energy, leads to the death of the cells and eventually the entire organism. Explaining the causality of death involves the understanding of the challenges cells and complex organisms face as they try to survive. Life depends on the continual copying and translation of genetic data since unfortunately our cells can’t continue indefinitely. Cells get damaged incessantly as DNA gets mutated, proteins get damaged, and highly reactive molecules called radicals disrupt membranes, to name a few of the damage-causing agents.
Natural death is usually not a sudden event. The process of ageing is what eventually leads to death as our body makes a trade-off between using energy for reproduction and to stay in good shape. Reproduction is the biological reason for our existence, the need to continue our lineage. Nearly all of our cells die; the only ones that survive are our germ or reproductive cells that fertilized successfully to create offspring. In a way it can be said that we never completely die since our genetic material exists beyond ourselves.
Our remaining body or somatic cells, however, lack this property due to ageing and eventually expire. This is because our body receives a limited supply of energy, of which the portion that goes into making and protecting egg and sperm is far greater than that which is used to maintain somatic cells such as skin, bone and muscle. Due to this lack of maintenance, cells accumulate damage over time, which ultimately causes some organ or the other to become diseased. If body functioning is compromised to too great a degree, death takes place. But can we escape this fate?
Enter rapamycin, a chemical that has opened up the gates to longevity and immortality. In 2009, scientists discovered that the drug could significantly extend life-span in mice by 9-14 per cent or the human equivalent of a decade by interfering with the activity of a protein called TOR, or mTOR. This protein exerts many of its effects as a complex called mTORC1, which, when food is plentiful in our bodies, induces increased insulin and related proteins, known as growth factors. The mTORC1 complex then reacts to these nutrients by stimulating the synthesis of cellular components and promoting cell growth and division. Simultaneously, the complex instructs cells to restrict autogaphy, a process that degrades the cell’s energy-producing mitochondria and molecules. When food or other resources are scarce on the other hand, the reverse happens; mTORC1 restricts itself, causing cells to focus on self-preservation over replication, while autophagy increases to provide an emergency supply of raw materials for cellular repair and energy production. In short, calorie restriction slows down the ageing process.
The problem arises after maturity, where mTOR1’s continued activity can lead to too much protein synthesis and the formation of destructive protein masses. Additionally, it could lead to the unwanted proliferation of certain cell types, such as smooth muscle cells that can contribute to atherosclerosis and bone-degrading osteoclasts, and declines in cell function and the promotion of cell senescence. mTORC1 activity also represses autophagy, allowing damaged material to accumulate in cells. What rapamycin does is inhibit the functioning of mTORC1, which interferes with the effects described above and, as a result, slows ageing and allows tissues to stay healthy longer.
The mystery, however, is: Why would any mechanism evolve to allow the retardation ageing in the first place? Evolution effectively equips organisms to live long enough to reproduce before environmental risks to survival such as predators, diseases, and accidents seal their fate, following which, as their probability of survival declines, their bodies deteriorate accordingly. The allowance of an alternative path is intriguing, to say the least. Several possibilities have been suggested for this counter-intuitive mechanism, the most common of which holds that calorie restriction taps an evolved starvation response that breaks an organism’s lean times so it can survive long enough to reproduce when conditions improve.
Other solutions put forth are that the calorie restriction extends life-span as a side-effect of responses evolved for purposes unrelated to ageing. These include the possibility that during lean times, animals branch out and eat unfamiliar, possibly toxic things in the wild and the body accommodates by activating the cellular stress-response and repair processes that accompany it and thereby unintentionally slowing the ageing process. Another novel theory put forward by Mikhail V. Blagosklonny, a cancer researcher at the Roswell Park Cancer Institute in Buffalo, New York postulates that calorie restriction’s apparent magic could be nothing more than a mere accident.
Although rapamycin’s possible side-effects of increasing blood cholesterol, causing anaemia and interfering with wound healing may rule it out as a candidate for anti-ageing in humans, other drugs such as metformin are being put forth as alternative candidates of ageing. So, the question isn’t whether or not we can slow the ageing process and possibly even eventually reverse it by manipulating our genomic and physiological processes; the question is when we’ll be able to do it. Humankind has already achieved incredible feats of ingenuity in a matter of a few centuries; on a cosmological time-scale, the end of mortality could be at hand!
So what would a world without death be like? Would all our philosophical and religious belief systems about god and the afterlife crumble, and our traditional reproductive and procreative days come to an end? Does life have more meaning because our time is limited, and will immortality be the burden described in Gulliver’s Travels where a few of the Luggnaggians never died, or would a legion of immortals contentedly inhabit our world? Let us leave that to imagination.
(The writer is a freelance contributor hailing from Guwahati who is studying in the US)