With Less Than 1% of Turtles Affected by Cancer, Researchers Believe They May Hold the Key to Battling the Disease

turtles have challenged the laws of the living for more than 250 million years. Their slow and armored body seems to escape the ravages of time. Some species, such as the giant turtles of Galápagos or Aldabra, reach weights of several hundred kilos while living more than 150 years. Such longevity, combined with a large size, should logically increase their risk of developing cancer. And yet, scientific data reveal the opposite.

A study published in July 2025 in Bioscience by Scott Glaberman and Ylenia Chiari reviewed the results of 290 autopsies made on 64 species of turtles from eight zoos distributed between Europe and the United States. As a result, the observed clever cancer rate was simply zero. Only a few mild cases have been identified, representing an overall prevalence of 0.34%. This figure is in total rupture with the rates recorded in mammals, where cancer affects an average of 10% of individuals, and even 17% among carnivores, according to a large comparative analysis cited by bioscience.

Why cancer in turtles defies the laws of biology

This paradox has long disconcerted the researchers. The more cells have cells, the more it accumulates risks of mutations and cancer drifts. It is the foundation of the famous Peto paradox, formulated in the 1970s, which stipulates that the size of an animal does not seem correlated to its probability of developing cancer. However, new analyzes, such as that published in February 2025 in PNAS, indicate that large terrestrial vertebrates have a higher cancer rate than small ones. The turtles would therefore be an exceptional exception.

Their secret would be due to a unique biological arsenal. Several studies evoke remarkable resistance to oxidative stress, a fine regulation of proteins and an exceptional capacity to engage apoptosis – this process by which a damaged cell is sacrificed to avoid any tumor drift. In giant turtles, some tumor suppressor genes are not only present in several copies, but also overexprimed, which would strengthen their ability to detect and neutralize abnormal cells before they proliferate.

An unexploited source of inspiration for human medicine

What turtles teach us goes beyond the framework of veterinary oncology. By resisting cancer with such efficiency, they offer an alternative model to species classically used in biomedical research. Their natural protection mechanisms against degenerative diseases could inspire new therapeutic strategies in humans, especially in the prevention of cell aging.

The Glaberman team recommends exploring the cell lines of turtles further, especially through in vitro experiments subjecting their cells to various biological stresses. This would unravel the deep mechanisms of their resilience. The slowness of their metabolism, their low production of free radicals and their robust antioxidant system could well form a winning combination against degeneration.

Few are the species that go through the centuries without giving in to the wear and tear of the living. The turtles may have found the parade. It is still necessary that science knows how to listen to what their silent longevity has to reveal.