“Astonishing!” Mammalian Species Found to Defy Aging Process –“Goes Against Everything We Know”




“To me this is the most exciting data I’ve ever gotten,” says Comparative biologist Rochelle Buffenstein. “It goes against everything we know in terms of mammalian biology.” In the world of animal models, naked mole rats are the supermodels. They rarely get cancer, are resistant to some types of pain, and can survive up to 18 minutes without oxygen. But perhaps their greatest feat, a new paper suggests, is that they don't age, flouting Gompertz law, a mathematical equation that describes aging.

The first study to analyze the life histories of thousands of naked mole rats has found that their risk of death doesn't go up as they grow older, as it does for every other known mammalian species, reports today's Science. Although some scientists caution against any sweeping conclusions, many say the new data are important and striking.

“This is remarkably low mortality,” says Caleb Finch, a biogerontologist at the University of Southern California in Los Angeles who was not involved in the new study. "At advanced ages, their mortality rate remains lower than any other mammal that has been documented.”

Scientists have long noted that naked mole rats—burrowing rodents with wrinkled, pink skin and large protruding teeth that live in large, subterranean colonies—show few signs of aging and far surpass the life span expected of a rodent this size. Mice in captivity live at most 4 years; based on their size, naked mole rats would not be expected to live past 6 years. Instead, some live beyond 30 years, and even at that age breeding females stay fertile.

Buffenstein, who works at the longevity-focused Google biotech spinoff Calico in San Francisco said naked mole rats seem to flout the Gompertz law, a mathematical equation that describes aging. In 1825, British mathematician Benjamin Gompertz found that the risk of dying rises exponentially with age; in humans, for instance, it doubles roughly every 8 years after the age of 30. The law applies to all mammals after adulthood, says Joao Pedro De Magalhaes, a gerontologist at the University of Liverpool in the United Kingdom.

But Buffenstein did not see this trend in her lab animals. After they reached sexual maturity at 6 months of age, each naked mole rat’s daily chance of dying was a little more than one in 10,000. It stayed the same the rest of their lives and even went down a little, Buffenstein reports this week in elife.

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Image credit:  National Geographic Creative/Alamy Stock Photo


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