Commentary: The surprising data behind supercentenarians

LONDON: 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 last year 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 Frenchwoman 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 World War I.

“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?

LONGEVITY REPORTED IN ENVIRONMENTS NOT CONDUCIVE TO HEALTH

No. In the United Kingdom, 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 are also notable for having a higher murder rate, a higher child poverty rate and a diet that, relative to the rest of Japan, skews away from seafood and vegetables and towards Kentucky Fried Chicken and Spam.

In the United States, Newman finds that the outstanding predictor of longevity is patchy birth records. Introducing proper records in the late 19th century reduced by more than two-thirds the number of babies who would eventually seem to reach the age of 110. That suggests that, until recently, seven out of 10 apparent supercentenarians were, in fact, younger than claimed.

FRAUD OR ERROR?

This all points to error or outright fraud. Elderly people are paid money simply for being alive, after all, so why call attention to their death? A younger relative can claim to be the pensioner and continue to receive benefits.

It brings to mind Goodhart’s law that “When a measure becomes a target, it ceases to be a good measure.” If superlongevity becomes a target, claims about age are not a good measure.

Is this common? It might be. Newman notes that the Greek labour ministry launched an investigation after the 2011 census counted fewer than 2,500 centenarians, yet 9,000 pensions were being paid to centenarians.

About the same time, the Japanese authorities found that the vast majority of centenarians – almost 240,000 out of 280,000 – were either missing or dead. Many Japanese records were destroyed during the war, then replaced during the US occupation. There is vast scope there for either fraud or error.

OLDEST HUMAN VERY MUCH AN OUTLIER

The late Jeanne Calment is very much an outlier, because 19th-century France had superb records by the standards of the age. There is no disputing that a baby girl named Jeanne Calment was born in 1875 in Arles, and there are very good reasons to believe that the woman who died in 1997 was the same person.

Some sceptics have advanced the idea that Jeanne died and was replaced by her daughter in the 1930s. This switch would certainly have been profitable: In 1969, when Jeanne was 94, her notary arranged that he would inherit her apartment in exchange for regular payments while she was still alive and in residence.

He paid her a fortune, then died before she did. If “Jeanne” was actually her daughter, the notary was grotesquely defrauded.

But could Jeanne’s daughter suddenly have pretended to be married to her own father? Would the locals really have fallen for the switch? A lengthy investigation by The New Yorker writer Lauren Collins found no evidence of fraud.

The only reason to doubt that Jeanne Calment reached the age of 122 is that nobody else has ever come close. Wikipedia lists 68 people who made it to 115. More than half of them died before reaching 116. More than half the survivors died before reaching 117. Only four people made it to 118, and only Calment to 120.

Calment is such an outlier as to stretch our credulity, but otherwise her claim to the record seems solid. Sometimes miracles happen, as in the case of Calment. And sometimes miracles should be disbelieved. Sorry, Bobi.