LONDON, July 17 (Xinhua) -- A study led by British scientists has revealed that turtles are remarkably resistant to cancer, with only about 1 percent of individuals affected -- a finding that could offer valuable clues for preventing or fighting cancer in humans.
The research, published in the journal BioScience, provides the strongest evidence to date that cancer is extremely rare in turtles, far less common than in mammals or birds.
The study was led by Ylenia Chiari, an associate professor from the School of Life Sciences at the University of Nottingham, alongside Scott Glaberman from the University of Birmingham, in collaboration with a team of researchers from zoos across the United States, Britain, and Europe.
"Our focus has been on understanding how aging and cancer risk evolve in different species -- and turtles stood out as a group that defies expectations," Chiari explained in an exclusive interview with Xinhua.
The team analyzed medical records and necropsies from hundreds of zoo turtles, including individuals from Chester Zoo in Britain.
"Species that are both large and long-lived are expected to face higher cancer risk, since more cells mean more opportunities for something to go wrong. But turtles seem to defy this pattern," said Chiari.
According to Chiari, turtles, especially iconic species like Galapagos and Aldabra giant tortoises, are famous for living long lives and growing to tremendous sizes. The study, which combines decades of zoo records with previous research, demonstrates how incredibly rare cancer is in these animals, highlighting turtles as an untapped model for understanding cancer resistance and healthy aging.
Their secret, explained Chiari, may lie in strong defenses against cell damage, a slow metabolism that reduces cellular stress, and unique genes that protect against cancer.
"One idea is that their slow metabolism may reduce the buildup of toxic byproducts in their cells, which could contribute to a longer lifespan. But emerging research suggests there's more to the story. Turtles may also be especially good at resisting damage to their DNA or at eliminating problematic cells before they can cause harm -- both of which could help explain their low cancer rates," said Chiari.
While the research team did not initially set out to cure cancer, Chiari acknowledged that any benefits for human cancer treatment would represent a significant bonus. However, she emphasized that turning these discoveries into medical breakthroughs would require close collaboration with experts in human cancer biology.
"The key question is whether the mechanisms that protect turtles from cancer also exist in humans -- or whether they can be replicated. It's far too early to say. But it's worth remembering that many of our biggest insights into human biology have come from model organisms like fruit flies, zebrafish, and nematodes. So, there's real precedent for animals like turtles helping us better understand human disease."
Chiari highlighted that studying long-lived animals presents unique challenges, especially when some live longer than humans themselves. This makes it difficult to track biological processes in real time, requiring researchers to rely on indirect clues from biology, genetics, and evolutionary comparisons and "also take advantage of the amazing network of zoos around the world, as we have done in this particular study."
"It's hard to say at this early stage what difference the new research will make to a better understanding of human health," added Chiari. "Our main aim is to uncover the unique biological pathways that allow turtles to resist cancer and age in a healthy way, so we can better understand the incredible diversity of life on Earth." ■