The thread of never-ending life has always been a part of the canvas of myths and religion — subsequently morphed seamlessly into everyday culture. Every religion and culture has their own telling of the tale. The Abrahamic religions have heaven, the Norse gods ate Iðunn’s apples, the Greek gods ate ambrosia and drank nectar, the Taoists sought the elixir of life, and the medieval alchemists sought the philosopher’s stone. Though these ancient symbols may have been metaphoric, with current technology eternal youth feels to be almost within our grasp. With organisations like Google Calico, A4M (American Academy of Anti-Aging Medicine), Human Longevity Inc and sponsors like Peter Thiel and Mark Zuckerberg, it seems as though humanity may finally taste that fountain of life.

To find immortality, one must understand mortality. Cells seemingly repair and divide without end, but they exhibit signs of ageing as well. The crux of the issue lies in the inherent structure of our genetic material, DNA. Human DNA is linear, so there must be two ends to the double helix. Every time DNA is replicated, information on the ends of the strands are lost. With increasing divisions, more and more information is lost to the point where the cell is no longer able to function – cells’ senescence. Cells with this kind of DNA structure must have an extra layer of molecular protection which ensure many healthy divisions before their eventual death. These protective elements are called telomeres. Telomere research has been a hot topic within the anti-ageing community, as its length is directly correlated to longevity. These DNA aglets are extra pieces of DNA which cap on to the ends of the double helix strand and tightly wraps itself together to protect the genetic material both from chemical and mechanical damage. However, this method is not fool-proof. Telomeres also run out, and with time all cells eventually die.

The miracle of the fountain of life, if it exists at all, can only be found in the moment of conception. In embryos, the DNA is refreshed, and old used telomeres are extended. Embryonic cells are a rare type of cells which express telomerase, the only protein capable of extending the length of telomeres. These little molecular machines use RNA as a template to extend the depleted telomeres, elongating the lifespan of the cell. Telomerases are also expressed in some stem cells, which supply the body with red blood cells and repair large damages. As attractive as telomerases sound as a solution to age, their over-expression can also become a problem. Many tumours and cancer types use telomerase as a tool to extend their lifespan indefinitely, outliving their healthy counterparts and taking over the body. To fine-tune the activity of this protein such that humans achieve eternal life while escaping the potential over-proliferation of cells is something that has yet to be achieved.

The most important breakthrough of 2016?

Telomeres, all in all, may only be one piece of the longevity biochemical puzzle. Many other biological processes are affected by age, although the precise mechanisms remain shrouded in mystery. Mitochondria become less efficient, transport to and from the nucleus becomes much less regulated, proteins are misshapen more often, and the DNA racks up too many mutations to efficiently repair them. It looks as though humanity still has so much to learn in terms of mortality that the seemingly tiny gap to eternal life may actually be a journey of a thousand miles.

Once we understand the essentials of life, will eternity still be attractive? The underlying basis of all living things is maintenance of a dynamic equilibrium, meaning that balance is maintained through constant life and death. The confusion of age for life has been recorded since the time of the ancient Greeks. When Eos mistakenly asked – on Tithonus’ behalf – for immortality and not eternal youth, what she really obtained from Zeus was eternal torture. The ancient Homeric hymns only remember Tithonus as a withered old man with no strength to even sit up, certainly an anecdote to keep us grounded in our search