Time to stop ageing (Image: Britt Erlanson/Stone/Getty)

Live long enough and your body stops ageing – so can we learn to stop the clock before our twilight years?

See gallery: “Secrets of the centenarians: Life begins at 100“

IN 1939, British statisticians Major Greenwood and J. O. Irwin published a little-noticed article in the journal Human Biology. Not only was 1939 a bad year for making scientific history, their article contained some fearsome mathematics, guaranteed to scare away most biologists and doctors.

The article also contained a profoundly unexpected discovery. Greenwood and Irwin were studying mortality figures for women aged 93 and over. They expected to see the death rate rising with age, as it does throughout adult life. But they did not. Instead, between 93 and 100 years of age the acceleration in death rates came to a screeching stop. Little old ladies aged 99 were no more likely to die than those aged 93.

Even the authors were dismayed. “At first sight this must seem a preposterous speculation,” they wrote. After all, like every other respectable biologist of the time, they assumed that “decay must surely continue”.

But what if it doesn’t? What if ageing stops? And if it stops very late in our lives, is there any way we can make it stop earlier, when we are in better health?

The idea that ageing stops makes very little intuitive sense. The fact of ageing has been well known to biology and medicine from their earliest days. Aristotle wrote a good book on the topic more than 2300 years ago. Like pretty much every biologist since then, he …