The world’s oldest tortoise could hold the secret to longer life for humans

The DNA from the world’s oldest tortoise may hold the secret to human ageing, as scientists say the animal’s super genes could lead to treatments that slow decline.

Jonathan, the 194-year-old giant tortoise, hatched in about 1832 in the Seychelles and is thought to be the oldest land animal.

Scientists say the Aldabra tortoise has the genes of a five-year-old to keep his cells full of energy and 287 unique gene variants driving his longevity.

The tortoise has spent most of its life on St Helena in the South Atlantic Ocean on the grounds of a Plantation House, after he was bought as a gift 144 years ago.

Researchers at the University of Cambridge were fascinated by his long lifespan and carried out DNA analysis which suggested Jonathan was good at repairing DNA damage, reducing inflammation, regulating insulin and suppressing cancer.

For the study published in the journal Science Advances, researchers compared the giant tortoise’s epigenome - the “on/ off” switches on his genes - with those of younger giant tortoises of the same species.

Remarkably, researchers found the switches controlling Jonathan’s DNA repair and metabolism genes were very similar to those in his younger relatives.

Usually, the epigenome changes over time, contributing to the ageing process - this is a key reason why things start to go wrong in older bodies.

As a result, the original function of many of his genes had barely altered throughout his life.

“We found that the gene regulators involved in energy production and DNA repair have remained incredibly stable in Jonathan over almost two centuries,” said Dr Justin Gerlach at Peterhouse at the University of Cambridge, who was involved in the study.

He added: “There are few creatures that could tell us more about ageing than the giant tortoises of the Galapagos and Seychelles islands. Working with a really old giant tortoise is such a privilege: you get a sense of the tortoise being your collaborator, not your study subject.”

A blood sample would be needed to help estimate the tortoise's life expectancy, but the request to draw blood from Jonathan was denied due to concerns about his health. However, the team was able to take a cheek scrape to carry out their analysis.

If researchers had access to a better sample, they could examine the length of his telomeres. These are the caps at the end of chromosomes which are used as indicators of life expectancy.

Researchers are hoping to study more animals with long lifespans in hopes of developing treatments that may be able to slow down ageing in humans.

"Nature has already solved the puzzle of ageing in remarkable ways, and Jonathan’s genome provides a blueprint for cellular resilience," said Stephen Clark senior author of the study.

He added: "Our goal is to take these evolutionary insights and immediately translate them into practical, affordable treatments for everyday people. Ageing is the greatest risk factor for nearly every chronic disease we face, and through the generosity of philanthropic partners, we can democratise access to longevity medicine."