For years, the so-called blue zones—regions where people reportedly live longer, healthier lives—have intrigued scientists and the public alike. In places like Okinawa (Japan), Ikaria (Greece), Ogliastra (Sardinia) and Nicoya (Costa Rica), residents lead a lifestyle that features natural movement, purpose, stress-reducing routines, mindful eating, a plant-based diet, moderate alcohol consumption, faith, family, and strong social ties. Researchers say these habits contribute to remarkable longevity.
But do blue zone residents really live longer? Or is their legendary lifespan more myth than science?
“People [in blue zones] reach age 100 at 10 times greater rates than in the United States,” according to a 2016 paper co-authored by Dan Buettner, an American explorer and journalist who coined the term ‘blue zones’. But Saul J. Newman, PhD, currently a research fellow at the Oxford Institute of Population Aging in the United Kingdom, has cast doubt on the reliability of the data behind these claims.
In a 2019 preprint published on bioRxiv, Newman uncovered a startling pattern: when U.S. states introduced birth certificates, recorded cases of supercentenarians—people living past 110—plummeted by up to 82 percent. Newman concluded that the striking concentration of centenarians and supercentenarians in blue zones may actually have little to do with healthy lifestyle factors, and is more likely the result of errors and fraud in record-keeping.
Newman pointed out that many blue zones share unexpected characteristics: low incomes, low literacy, high crime rates, and shorter-than-average national lifespans—factors that, logically, should reduce longevity, not extend it. “The hypothesis that these relatively low literacy rates and incomes are generating age-reporting errors and pension fraud, and therefore remarkable age records, seems overlooked,” he wrote.
In 2024, Newman doubled down with another preprint, in which he highlighted a statistical red flag in blue zone data. Supercentenarian birthdates are concentrated on days divisible by five: a pattern indicative of widespread fraud and error.
In a joint statement issued in October 2024, multiple leading blue zone researchers strongly rebutted Newman’s critique, arguing that he overlooked the rigorous age verification and statistical analysis involved in identifying blue zones.
In the case of Sardinia, for instance, the ages of centenarians in blue zone villages were cross-checked using multiple sources: civil status databases dating back to 1866, handwritten church records from the 17th century onward, and a complete genealogical reconstruction of village inhabitants from 1866 onward.
“Not only were the birth and death dates of each centenarian confirmed, but those of their siblings were also cross-checked,” the researchers wrote. “This allowed us to rule out any possible identity switches, such as the case of a false supercentenarian that was rigorously eliminated from our Sardinian centenarians’ database.”
Similarly, in Nicoya, Costa Rica, blue zone researchers did not rely on self-reported age, but used birth dates drawn from the country’s civil registry.
They also dismissed Newman’s claims about birthdate patterns or age heaping, noting that no such issues have appeared in their datasets.
In response to Newman’s statement about high levels of crime and poverty in Sardinia’s blue zone, the researchers noted that broad regional statistics were not representative of the small rural villages that formed the blue zone.
While they refute Newman’s concerns about inaccurate age data, blue zone researchers have acknowledged that the longevity advantage these regions once held may be slipping away.
In 2023, demographer Luis Rosero-Bixby, PhD, published a study revealing a troubling shift in Nicoya, Costa Rica: people born after 1930 in Nicoya are no longer living unusually long lives. The study found that while Nicoyan men born in 1905 had 33 percent lower mortality rates than the rest of the country, those born in 1945 actually had 10 percent higher rates.
Okinawa’s once-unmatched longevity is also declining, according to a 2024 paper by demographer Michel Poulain, PhD. While the older generations still experience significant longevity benefits, the younger generations show higher mortality rates compared to mainland Japan. Researchers attribute the decline in Okinawa’s longevity rates to the arrival of modern diets and transportation.
This decline in longevity among newer generations suggests that extreme longevity hotspots are probably transient, according to Rosero-Bixby. While people in these areas may have lived longer than average until recently, this advantage is rapidly vanishing.
This story is part of Popular Science’s Ask Us Anything series, where we answer your most outlandish, mind-burning questions, from the ordinary to the off-the-wall. Have something you’ve always wanted to know? Ask us.
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