The surprising data behind supercentenarians

Tim Harford

If there is a Dog Heaven, what must Bobi be thinking as he gazes down? Bobi’s place in the record books seemed assured when he died in October at the age of 31 years and 165 days — more than two years older than his closest rival for the title of the oldest dog who ever lived. Alas, Guinness World Records has stripped Bobi of his record on the basis that “without any conclusive evidence available to us . . . we simply can’t retain Bobi as the record holder”.

If we cannot believe that Bobi the dog was really as old as was claimed, what are we to make of the claimants to human longevity records? The oldest human ever was Jeanne Calment, who died in 1997 at the age of 122, having met Vincent van Gogh when she was a teenager in Arles in 1888. (Calment recalled that van Gogh was “very ugly. Ugly like a louse.”)

To demonstrate such claims requires good records, which is a problem, because the key fact that needs to be verified — a date of birth — only becomes interesting to most observers a century or so after the event in question. By definition all surviving supercentenarians (110 years and up) were born before the first world war.

“No single subject,” the Guinness Book of Records declared in 1955, “is more obscured by vanity, deceit, falsehood and deliberate fraud than the extremes of human longevity.”

Saul Newman, a demographer at Oxford university, has examined the data describing the population of semi-supercentenarians (aged 105 or more) and of supercentenarians. What might predict such extraordinary longevity? Eating plenty of vegetables, perhaps — or a strong social network?

No. In the UK, Italy, France and Japan, Newman finds instead that “remarkable longevity is . . . predicted by regional poverty, old-age poverty, material deprivation, low incomes, high crime rates, a remote region of birth, worse health”. You read that right. They are all factors that are associated with worse population health and a lower probability of reaching 90.

It seems that the very environments that are least conducive to health are the places where people with claims to astonishing longevity pop up. Tower Hamlets — by several measures the most deprived borough in London — also has the highest proportion of supercentenarians.

Another example is Okinawa. Some parts of Okinawa are super-longevity hotspots for Japan, but

The full article is available here. This article was published at Tim Harford.