A 105-year-old villager in Perdasdefogu, Italy, on the island of Sardinia, a so-called "blue zone". Photo / Gianni Cipriano, The New York Times
The premise is catchy, but some think it’s based on faulty data.
The concept is simple and alluring: there are special regions around the world — called blue zones — where people regularly remain vibrant and active into their 90s and 100s, thanks to a simple set of behaviours anyone can follow.
It’s sensible enough to sound convincing, and ambiguous enough to support a health and longevity empire. In the 20 years since blue zones were first introduced, the Blue Zones brand (now trademarked) has spawned eight books, a Netflix series, product partnerships (Langers Blue Zones iced tea, Bush’s Blue Zones canned bean soups) and a multimillion-dollar programme for other cities to become “Blue Zones certified” — all in the name of helping people attain their longevity goals, ostensibly by mimicking the lifestyle habits of the individuals living in each region.
But not everyone is buying into it. Some experts — one in particular — are questioning whether the blue zones themselves, those bastions of health, might be too good to be true.
The term “blue zone” was first used in 2004 in an article published in the academic journal Experimental Gerontology, about centenarians in Sardinia, Italy. In the paper, researchers used the colour blue to shade portions of a map of the island denoting where people had exceptional longevity. They speculated that this may be attributed to nutrition and lifestyle, or it could be thanks to “the high rate of inbreeding” in the isolated regions, which conceivably led to protective genetic characteristics becoming more prevalent in the population.
The idea gained momentum the following year, when National Geographic reporter Dan Buettner used the phrase in a feature story highlighting three regions — Okinawa, Japan; Loma Linda, California; and Sardinia — where research had found people lived longer and more healthily than average.
In the article, Buettner attributed the longevity and vitality of the regions’ citizens to their healthy behaviours. People from these places, he concluded, were more likely to eat a nutritious diet with lots of fruits and vegetables, get plenty of physical activity, prioritise family and community, and not smoke cigarettes. Drinking in moderation, not eating too much, managing stress, having a purpose in life, dedication to religion and good genes were other factors mentioned.
“These people in blue zones, they’re not doing any of the things” we typically do to get healthy, Buettner said in an interview with The New York Times. “They’re not on diets or CrossFit or getting on Instagram and getting supplements or running down to Tulum for stem cells. You know, none of these longevity hacks. But somehow, they’re living about 10 years longer.”
Rather than people pursuing health, Buettner added, the blue zones illustrate that good health comes from being in “the right environment”.
Since publishing his initial article, Buettner has partnered with demographers, public health researchers, geriatricians and other experts to expand on the idea of blue zones, adding Nicoya, Costa Rica, and Ikaria, Greece, to the list. He also launched the Blue Zones business and rebranded the key behaviours as the “Power 9″ (genetics and not smoking are no longer mentioned).
Buettner sold Blue Zones in 2020 to Adventist Health, a healthcare provider system “founded on Seventh-day Adventist heritage and values”. (Loma Linda has one of the highest concentrations of Seventh-day Adventists in the country.)
It all started in 2019 with an academic preprint paper. The study, which was updated this year and has not been published in a peer-reviewed journal, claimed that areas with high numbers of centenarians and supercentenarians (people 110 and older) have something else in common: faulty record-keeping. In other words, more people are living past 100 only on paper, not in reality.
The study, conducted by Saul Justin Newman, a senior research fellow at the Centre for Longitudinal Studies at University College London, was not focused on blue zones specifically. Instead, Newman analysed databases of centenarians and supercentenarians from the United States, France, England, Italy and Japan and then looked for hot spots in those countries where many of them lived. These hot spots didn’t entirely line up with the blue zones, though there was some overlap.
“I found that they all came from poor areas that generally had terrible outcomes at old age, that had some of the worst life expectancies of their countries,” Newman said. “Every indication was that these high densities of supercentenarians were just down to poverty and fraud.”
Newman, who has a history of critiquing longevity studies, said that low literacy rates and poor record-keeping resulted in an absence of birth certificates around the beginning of the 20th century. Consequently, many older people may not know how old they are, and without legitimate paperwork, their ages are virtually impossible to verify. In other instances, an older relative may have died, but no one registered the death, so it looks like the person keeps getting older — and the family keeps receiving their pension cheque.
Independent analyses have uncovered these types of anomalies. For example, in 2010, the Japanese Government revealed that 230,000 centenarians were “missing” — likely the result of unreported deaths. (A subsequent paper argued that these numbers were overblown.)
Newman thinks blue zones suffer from these same issues and has said in interviews that they are “the epitome” of bad record-keeping inflating the number of centenarians.
When asked what he thinks of Newman’s conclusions, Buettner said he wasn’t surprised that some claims of centenarians turn out to be fraudulent but insisted that it wasn’t happening in the regions he has deemed blue zones. He said the methods he and his team of researchers use are rigorous, involving numerous trips to the regions to verify birth records using multiple sources of information and to interview nonagenarians, centenarians and their families. He added that they’ve also investigated other areas around the world as potential blue zones, but those did not meet the criteria.
Several of Buettner’s academic collaborators wrote a rebuttal letter in response to Newman’s article, saying that four of the blue zones “have been fully validated by strict demographic criteria”. In Sardinia, for instance, that included comparing civil databases, handwritten church archives and genealogical reconstructions. The fifth blue zone, Loma Linda, was not mentioned.
That may be because Loma Linda was “kind of an outlier,” Buettner admitted: It was initially included because his editor at National Geographic told him, “You need to find America’s blue zone”.
Not necessarily. Newman’s theory has not been widely accepted by other academics, and his paper making these claims is still unpublished. He did recently win an Ig Nobel award for the research — a farcical spin on the Nobel Prizes that honours “achievements so surprising that they make people laugh, then think”.
Nadine Ouellette, an associate professor of demography at the University of Montreal, who is not involved in the Blue Zones brand, said the problems Newman raised exist. And the older a person is, “the more issues you come across in terms of accuracy” of their age.
But, she added, demographers are acutely aware of these concerns, and as a result, they work to verify the age of very old individuals with multiple pieces of information, not just birth and death certificates.
Ouellette also raised concerns about some of the methods and data sources used in Newman’s paper, saying they are “very unusual”.
Beyond the critiques from Newman, two of the original blue zones, Okinawa and Nicoya, might no longer qualify as such. Buettner said that’s because their traditional ways have been replaced by modern diets and lifestyles over the past two decades. “Since I started studying these places,” convenience stores and fast-food restaurants have come in, he said. “It breaks your heart.”
“I think you’re going to expect to see all these blue zones gone within a generation or even half a generation,” Buettner added.
Regardless of whether these places are — or were — for real, ageing experts emphasised that the lifestyle behaviours the Blue Zones brand has helped to popularise are important for longevity. There’s little doubt that a nutritious diet, physical activity and community can help people live longer and healthier lives.
“Are the concepts of blue zones consistent with what we know about ageing? Absolutely,” said Dr Nir Barzilai, director of the Institute for Ageing Research at the Albert Einstein College of Medicine.
But, Barzilai added, the blue zones themselves, and the theories behind them, have not necessarily been validated scientifically. “It’s not a study; it’s an observation,” he said. “It’s an observation which is consistent with what we think we know about ageing. But it’s not a science.”
©2024 THE NEW YORK TIMES
The century-old British carmaker's new logo and latest ads have raised eyebrows.