

Although it was known that the little subterranean creatures never develop cancer, and live far longer than similar-sized mammals, researchers have now discovered they can also survive for 18 minutes without oxygen. What is even more astonishing is how they manage it.

They effectively become plants, altering their metabolism so that cells are powered by fructose rather than glucose, a process which requires no oxygen. The unique back-up system completely protects sensitive organs such as the heart and brain.



"Our work is the first evidence that a mammal switches to fructose as a fuel," said Professor Gary Lewin, of the Max Delbruck Centre of Molecular Medicine in Berlin.



Humans need an atmosphere that has at least 10 per cent oxygen to survive, but naked mole rats have evolved to live in stuffy underground burrows in the African desert which can be 25km long, and have little air.

They are also highly social creatures that snuggle together at night for warmth, but can end up nearly suffocating if they are trapped in the middle of a "mole ball".

In the new study, the researchers exposed naked mole rats to low oxygen conditions in the laboratory and found that they released large amounts of fructose into the bloodstream, a metabolic process previously only seen in plants.



"This is just the latest remarkable discovery about the naked mole rat - a cold-blooded mammal that lives decades longer than other rodents, rarely gets cancer, and doesn't feel many types of pain," said Thomas Park, professor of biological sciences at the University of Illinois at Chicago, who let the research. "The naked mole rat has simply rearranged some basic building-blocks of metabolism to make it super-tolerant to low oxygen conditions."

The scientists also showed that naked mole rats are protected from another deadly aspect of low oxygen - a buildup of fluid in the lungs called pulmonary edema that afflicts mountain climbers at high altitude.

The research was published in the journal Science.