Researcher Saul Newman Calls Blue Zone Data Flawed as New Study Claims Sardinian Village Has Record Female Longevity

The Blue Zone idea has sold books, filled a Netflix series and launched diet plans. Two new pieces of work pull in opposite directions on whether the data underneath it holds up.

One is a book and interview campaign from Saul Justin Newman, a senior research fellow at University College London and the University of Oxford. The other is a peer-reviewed study from the researchers who coined the Blue Zone brand, claiming to have found a new one.

The skeptic's case

Newman's book is called Morbid: Debunking Modern Longevity Science. He describes it as a skeptical, irreverent look at the business of lengthening human lifespans, and says he finds the data wanting.

He told Scientific American's Science Quickly podcast that he got into the field almost by accident. A friend sent him a paper in Nature arguing for a limit to human life of roughly 115 to 125 years. Newman says the authors reached that conclusion by accidentally rounding off data at the oldest ages to zero.

He calls it "completely awful." Eight years later, he says, he is still trying to get the paper retracted.

His broader argument is that if standards of evidence are that low in a top journal, the underlying claims about extreme old age deserve scrutiny. He compares his work to air crash investigation: something has gone drastically wrong, and he wants to know what.

In an excerpt from the book published by MIT Press, Newman points to the case of Adele Dunlap, a former smoker and occasional drinker who was at one point recorded as the oldest woman in the United States. Newman writes that Dunlap spent nearly a decade insisting her paperwork was wrong and that she was about a decade younger than her records said.

Asked how it felt to be 113, she answered, "I'm 104," according to a quote Newman reproduces. The newspaper reporter countered that the Los Angeles-based Gerontology Research Group, which tracks people 110 and older, had validated her age.

Newman's point: when a paper record and a living person disagree, the record won.

The Bolotana study

National Geographic Explorer Dan Buettner, who built the Blue Zone brand, and co-researcher Gianni Pes now say they have found another one. It is Bolotana, a town in the Marghine mountains of Sardinia.

The village has about 2,262 residents, 10 of them at least 100 years old. That works out to roughly 442 centenarians per 100,000 people, about 10 times the Sardinian average and 11 times the U.S. average, according to the research team.

"By some measures, Bolotana is the most extraordinary blue zone," Buettner said in an interview. "While the other blue zones are waning, this one is waxing. In other words, every year there are more centenarians."

The other places Buettner has previously labeled Blue Zones are Okinawa, Japan; Ikaria, Greece; and a cluster of mountain villages elsewhere in Sardinia.

How the ages were checked

The team included gerontologist S. Jay Olshansky, who ran an age-verification process on a randomized sample of the village's known centenarians. The results appear in Frontiers in Aging.

Olshansky said Bolotana has something he has not seen elsewhere: photographs of every single centenarian. He randomly picked centenarians from those photos, then cross-checked births and deaths against baptism and marriage records to confirm each had reached 100.

"In Bolotana, we discovered that the life expectancy of females, in particular, is significantly higher than that observed among the longest-lived populations in the world," Olshansky said.

The study reports the chance of surviving from age 70 to 100 was 4.92 percent for men and 13.83 percent for women in the village. Women who reached 70 were three times as likely to reach 100 as American women, per the researchers.

Olshansky said the finding "didn't have to be that dramatic to be important."

That female-driven pattern sets Bolotana apart from other Blue Zones. Olshansky noted there is generally a three-to-five-year female advantage in lifespan.

What the numbers rest on

The headline rate is built on 10 people. In a village of 2,262, one or two additions or subtractions move the per-100,000 figure sharply. The researchers' answer is the record trail: baptism, marriage and death documents cross-checked against photographs for a random sample.

Newman's published argument is about the reliability of age records at extreme old age and the way errors in them survive. The Bolotana team is claiming that, in this one village, it checked the records against several independent documents. Nothing in the Bolotana study, as described by its authors, addresses Newman's broader critique of Blue Zones or of the field's validation system.

Olshansky himself said the village's photographic record is something "we've never seen anywhere else and probably will not see anywhere else." So the same level of verification may not exist for Okinawa, Ikaria or the other Sardinian villages. Whether those earlier Blue Zone claims can be tested the same way is still unanswered.