What's the secret to a superlong life? Ask someone who's had one, and they'll say it's their daily glass of whiskey, avoiding men, or eating delicious things. But a new study suggests the secret instead could be exaggeration and a touch of fraud. At least, that could explain the handful of regions around the world known as "blue zones," where residents famously live well past 100.
Sardinia, Italy, and Okinawa, Japan, are among these blue zones. Both of these regions have one thing in common (aside from their quaint seaside villages): a remarkably high number of supercentenarians, or residents who live past 110 years. But there's a catch. One would expect communities within these blue zones to have high life expectancies. In fact, the opposite is true. These regions that boast some of the oldest people in the world also have some of the lowest life expectancies, the new study, published to the preprint journal BioRXiv on July 16, finds.
So what gives?
To understand what might be causing this discrepancy, it's helpful to look at the United States as a case study. At the end of the 19th century, the U.S. boasted a much larger population of supercentenarians. But around the turn of the 20th century, that number steadily decreased. That pattern had nothing to do with deterioration in the country's health. In fact, the overall life expectancy was steadily increasing around that time (and continued to do so, even as the number of supercentenarians dropped). Instead, what has changed is our record-keeping habits. More specifically, they got a lot better.
Across the U.S., states started recording vital information — using birth and death certificates — at different times. Each time a state began formally recording births, the number of people over 110 mysteriously dropped off by 69% to 82%, the study author found.
That means that for every 10 recorded supercentenarians, seven or eight were younger than records said they were, Vox reported. That doesn't mean that they were lying — but it does mean that due to error, supercentenarians are probably a lot less common than we think, especially in areas with poor record keeping.
So what does this all have to do with Italy and Japan? The U.S. stands as an example of how misreported ages can drastically skew the number of supercentenarians we see reported in a population. As it turns out, Italy has kept vital records for hundreds of years. But that's not proof that Sardinia deserves its famed blue zone designation.The researchers identified clues that there are other sources of misreported data in these supposedly super-old communities.
The researchers found that blue zones all followed a suspicious pattern — none of them had the characteristics you'd expect of a healthy aging population. In these regions, the more supercentenarians there were, the lower the life expectancy. Instead of good-quality health care, a large population of 80 year olds and a high quality of life, they found low literacy, high crime rates and poor health outcomes. These factors suggest that there's something fishy going on with the data. The researchers suggest that misreports could be partially to blame, but that pension fraud — claiming other's identities to receive a pension — is also likely.
This is a controversial claim — but it's not the first time blue zones have been called into question. In 2010, an investigation into Japanese records found that 238,000 people greater than 100 years of age were actually missing or dead, leaving just 40,399 with known addresses, BBC reported. At that time, officials reported that many of the supposed centenarians had actually died or left the country following World War II. Another investigation earlier this year presented evidence that Jeanne Calment, who at 122 years old was the oldest woman whose age was well-documented, was actually her 99-year-old daughter, claiming her identity for a pension. Fraud and misreported data might seem especially unlikely in the case of Calment given how well-documented her life was, and the investigation's allegations of fraud haven't been confirmed. But it happens all the time, even among the highest-profile supercentenarians, said Saul Newman, a data scientist at Australian National University and author of the new BioRXiv study.
"The first two people to reach 112 were validated, then retracted. The first three people to reach 113 suffered the same fate," he told Live Science in an email. "The ways in which these errors can escape detection, even under interview, are diverse."
Finally, he cited the example of Carrie White, the former oldest woman by three years. White was "validated" as a supercentenarian for 23 years until a typographical error was identified in old mental-asylum records, Newman said. "Honestly, if your data depends on the handwriting of 1900's asylum orderlies, are you surprised by suggestions that these data are perhaps unreliable?" he added. It's far-fetched to imagine that nearly every cluster of supercentenarians can be accounted for by bungled data or fraud. But the study actually isn't proposing that whole villages of people are lying about their ages. Instead, it highlights a common problem in science: when looking at incredibly rare populations or conditions, data — and our understanding of the world — can easily become skewed.
Think about it this way: Imagine a group of 1,000 people, all over 100 years of age. Statistically, only one should survive to 110, Vox reported. Now imagine that another person in this same group, who isn't yet 110 lies and says they are. That's not many lies — but it still effectively doubles the number of supercentenarians we measure.
So is there a secret to living past 100? Perhaps. But according to this study, examining the elderly populations of Italy and Japan won't reveal it to us.
The study is still awaiting peer review and publication in a scientific journal.
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Originally published on Live Science.
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Isobel Whitcomb is a contributing writer for Live Science who covers the environment, animals and health. Her work has appeared in the New York Times, Fatherly, Atlas Obscura, Hakai Magazine and Scholastic's Science World Magazine. Isobel's roots are in science. She studied biology at Scripps College in Claremont, California, while working in two different labs and completing a fellowship at Crater Lake National Park. She completed her master's degree in journalism at NYU's Science, Health, and Environmental Reporting Program. She currently lives in Portland, Oregon.