Last updated November 24, 2017 at 3:03 pm
Life expectancy has risen drastically over the last century. Even some in developing countries are expected to live to the grand old age of 80, some 33 years longer than expected at the turn of the 1900’s. It’s estimated that Earth currently houses 450,000 people that have lived to see a full century, with this figure set to increase eightfold to 4 million by the year 2050. But perhaps this figure is an understatement.
Despite the ever-increasing age limit of our population, society has long had a fixation on finding Ponce de Leon’s proverbial Fountain of Youth in order to extend our existence into distant millennia and beyond. Numerous efforts have been made to crack the key to immortality, ranging from long-winded global expeditions to human sacrifice and blood rituals. However, research efforts have revealed that the key may be within ourselves.
In 1984, Australian-American scientist Dr Elizabeth Blackburn discovered the prime candidate supposedly responsible for moderating aging was an enzyme (a type of protein) called ‘telomerase’.
This enzyme is responsible for generating protective caps called ‘telomeres’ at the end of each chromosome in order to protect them from corrosion and interactions with other chromosomes. Think of telomeres as the wax coating on the end of a rope – while the coating remains intact it stops the rope from fraying.
Your body is constantly replacing cells and each time this occurs a new copy of your chromosomes are replicated, with slightly less of your chromosomes being copied each time. Luckily, the part of the chromosome that is lost is a portion of the protective telomere caps and these are constantly replenished by the telomerase enzyme. However, telomeres do shorten over time and this shortening has been strongly linked with ageing in humans.
Though normal human cells are unable to protect their chromosomes with telomeres indefinitely, some species appear to be able to. Lobsters cells, for example, constantly produce telomerase en mass, preventing their chromosomes from damage and allowing them to continue replication indefinitely. This phenomenon results in incredibly long lifespans in a species – in 2009 a 20-pound (~17 kg) lobster named George was found in Canada and it was estimated that the crustacean was a least 140 years old!
Study into the activity of lobster telomerases presents an exciting avenue of research into the ageing process – a field that that could also encompass the study several other long-lived species including the bowhead whale (oldest ~200yrs), Aldabra giant tortoise (oldest ~250yrs), deep sea perch (oldest ~150) and many more.
Scientists hope to study the mechanisms governing telomere production and its association with halting the ageing process across a wide range of species with the hopes of producing viable solutions for our own species’ quest for immortality. So while we may possibly know the key, research into these mechanisms still has some way to go before any secrets are unlocked! Nonetheless, with the role of telomerase and telomeres in the process of ageing being held as a hot topic, the scientific community edges ever closer to reaching the fabled Fountain of Youth we’re all hoping for.
Image credit: Conrad Erb/Wikimedia