- The term "blue zone" comes from a 2004 study by demographer Michel Poulain and physician Gianni Pes, who marked an area of exceptional male longevity in central-eastern Sardinia in blue on their map.
- The five regions usually listed as blue zones are the Barbagia area of Sardinia, Ikaria in Greece, the Nicoya Peninsula in Costa Rica, the Seventh-day Adventists of Loma Linda in California and Okinawa in Japan.
- Dan Buettner's National Geographic cover story "The Secrets of Long Life" (November 2005) and his 2008 book "The Blue Zones" made the concept known worldwide.
- The Okinawa Centenarian Study, begun in 1976, found 40–50 centenarians per 100,000 people in Okinawa when most industrialised countries had 10–20.
- Okinawan men fell from 1st place among Japan's 47 prefectures in life expectancy (1980, 1985) to 26th in 2000 and 43rd in 2020, according to Japan's Ministry of Health, Labour and Welfare.
- Researcher Saul Newman has questioned the age records behind blue zones in preprints; blue-zone researchers reply that ages in Sardinia and Okinawa were validated document by document, so the debate remains open.
What are the blue zones?
Blue zones are regions where researchers recorded a much higher share of very old people than in the surrounding country, especially centenarians and people in their nineties who still lived independently. Five places carry the label today: the mountainous Barbagia area of Sardinia, the Greek island of Ikaria, the Nicoya Peninsula in Costa Rica, the Seventh-day Adventist community around Loma Linda in California, and the Japanese island prefecture of Okinawa.
The idea behind the term is simple. If a few populations live far longer than their neighbours, their way of life may hold clues about healthy ageing. That idea is useful, but it is also where most misunderstandings start: a blue zone is an observation about a group of people born in a particular era, not a proven recipe and not a permanent feature of a place.
Three different things are often mixed together under the same name. There is the demographic finding (unusual longevity in a specific area), the journalistic synthesis (common habits described by Dan Buettner and his teams), and the commercial programme run today by the company Blue Zones LLC. Keeping these apart is the easiest way to read anything about blue zones critically.
Where did the term "blue zone" come from?
The term comes from Sardinia. Demographer Michel Poulain and physician Gianni Pes studied where on the island people born between 1880 and 1900 had reached 100. They used an "extreme longevity index", the share of a birth cohort that became centenarians, and found a cluster of mountain villages in central-eastern Sardinia where the index was exceptionally high. They outlined the area in blue ink on their map, and the "blue zone" was born.
What made the Sardinian finding unusual was not only the number of centenarians but who they were. Women usually outlive men by a wide margin, yet in the blue zone the ratio of female to male centenarians was 1.35, against 2.43 in the rest of Sardinia. Men there were reaching very old age almost as often as women.
The study was published in 2004 in the journal Experimental Gerontology as part of the AKEA project. It is a demographic paper: it identifies where exceptional longevity occurred and checks the ages, but it does not claim to explain why.
Blue zones list: the five regions and what research shows
The list of five comes from Blue Zones LLC, the organisation built around Dan Buettner's work. The regions are very different in climate, religion and diet, which is part of why the concept attracted so much interest.
A 2025 scoping review in the journal Aging and Disease went through 65 records about ten regions that had been described as blue zones. It found that Ogliastra in Sardinia, Okinawa and Nicoya do show higher longevity than their national averages, found no studies at all for Loma Linda, and noted that Rugao in China, sometimes proposed as a new blue zone, has fewer centenarians.
| Region | Country | Population studied | What the evidence says |
|---|---|---|---|
| Barbagia / Ogliastra, Sardinia | Italy | Mountain villages, people born 1880–1900 | Original 2004 finding; higher longevity confirmed in the 2025 review |
| Okinawa | Japan | Older Okinawans, especially those born before the war | Okinawa Centenarian Study since 1976; ages validated in 2008; current ranking has fallen |
| Nicoya Peninsula | Costa Rica | Rural older adults | Higher longevity than the national average in the 2025 review |
| Ikaria | Greece | Island population | Listed as a blue zone; questioned in Newman's preprints |
| Loma Linda | USA | Seventh-day Adventist community | No studies found by the 2025 scoping review |
So the five regions do not rest on equal evidence. Sardinia and Okinawa have the longest research record, Nicoya has supporting data, and Ikaria and Loma Linda depend more on the original reporting.
How Dan Buettner made blue zones famous
The concept reached the general public through journalism. Dan Buettner's cover story "The Secrets of Long Life" in National Geographic in November 2005 featured three places: Okinawa, Sardinia and the Adventists of Loma Linda. His book "The Blue Zones: Lessons for Living Longer From the People Who've Lived the Longest" followed in 2008 and added the other regions.
Buettner's team summarised the habits they saw in these regions into a list of nine lessons, sold today under the registered trademark "Power 9". The list includes moving naturally, having a sense of purpose, slowing down, eating until about 80 percent full, eating mostly plants, belonging to a community, putting family first and keeping the right social circle. It is a journalistic synthesis and a brand, not a research finding with its own trial behind it.
This distinction matters because most popular articles present the nine habits as "what science says". The demographic studies confirm unusual longevity in some of these regions; they do not test which habit, if any, caused it.
What do the blue zones have in common?
Reports from the five regions describe a recognisable pattern of everyday life among the old people who were interviewed. They moved all day as part of ordinary work, gardening, walking and herding rather than through sport. They ate mostly plant foods, often from their own land, in modest amounts. They lived inside dense family and village networks, and many kept a clear role or purpose into old age.
Seen this way, the shared traits are less about special foods and more about a whole way of life in poor, rural communities of the early and mid 20th century. Several of the regions are mountainous or island areas where people had to walk, cooperate and grow their own food.
Two cautions belong here. First, these are descriptions of people who survived to very old age, collected decades later; people who died young are not in the picture. Second, the same communities also had hardships that nobody recommends copying. The pattern is worth knowing, but it describes a past world rather than a checklist that guarantees a long life today.
Okinawa longevity: what the Okinawa Centenarian Study found
Okinawa is the best-documented of the blue zones. The Okinawa Centenarian Study was started by cardiologist and geriatrician Makoto Suzuki of the University of the Ryukyus and is described by its authors as the world's longest-running population-based study of centenarians, beginning in 1976. More than 900 centenarians have been examined. Twin brothers Bradley and Craig Willcox joined as co-investigators.
In a 2006 paper the team reported centenarian prevalence in Okinawa as high as 40–50 per 100,000 people, compared with about 10–20 per 100,000 in most industrialised countries. Longevity also clustered in families: female siblings of Okinawan centenarians were 2.58 times and male siblings 5.43 times more likely to reach 90 than others of their birth cohort.
Doubts about birth records are an obvious question for any centenarian study, so the team checked. A 2008 validation study, titled "They really are that old", compared self-reported ages with documents for a subset of centenarians and found that the ages matched and that Okinawa's age registration system was reliable. The researchers also published a popular book, "The Okinawa Program" (2001).
Okinawa diet: what Okinawans ate in 1949
The famous Okinawa diet is a historical diet, recorded mainly from post-war survey data. Using archived figures, the Willcox brothers and colleagues reported that Okinawans in 1949 ate about 1,785 kilocalories a day, against 2,068 for Japan as a whole in 1950, and that the older generation had little weight gain with age and a life-long low body mass index. The authors presented this as observational support for the idea of caloric restriction, not as proof.
The staple was the sweet potato, which had replaced rice in the 1600s after arriving from China. In the 2007 paper's breakdown, sweet potato supplied about 69 percent of calories, rice 12 percent, other grains 7 percent, legumes including soy 6 percent, and fish only about 1 percent. A 2014 review of the same diet, using a different classification, put the macronutrient split at about 85 percent carbohydrate, 9 percent protein and 6 percent fat.
That diet no longer exists in everyday Okinawa. Eating habits on the island converged with mainland Japan after the war and especially after Okinawa's return to Japan in 1972, and fat intake rose to around 27 percent of energy. The diet belongs to the generation that produced the centenarians, which is exactly why later generations did not inherit its results. The traditional Okinawan practice of eating only until about 80 percent full has its own page in this section.
Is Okinawa still the longest-lived place in Japan?
No. Japan's Ministry of Health, Labour and Welfare publishes life expectancy for all 47 prefectures. Okinawan men ranked 1st in 1980 and 1985, then dropped from 4th to 26th in the 2000 tables, a fall that Okinawan doctors called the "26 shock". By 2020 they were 43rd. Okinawan women were 1st in every census year from 1975 to 2005, then 3rd in 2010, 7th in 2015 and 16th in 2020.
The fall is driven by middle-aged adults rather than the old. In 2020 Okinawan men still ranked 2nd for life expectancy at age 75 and women 1st at 65 and 75, while working-age mortality, with liver disease and diabetes among the leading causes, pulled life expectancy at birth down. One analyst argued that part of the 2000 drop simply reflected the shrinking share of long-lived pre-war cohorts.
Centenarian numbers tell the same story. Okinawa led Japan in centenarians per 100,000 until fiscal 2009, then slid year by year to 37th place in 2025, with 77.56 per 100,000. Shimane prefecture has held first place since, with 168.69 per 100,000 in 2025. Across Japan there were 107,677 people aged 100 or older in September 2026, the first time the number passed 100,000.
Moai, yuimaru and Ōgimi: belonging in Okinawa
Moai is often presented as an Okinawan circle of lifelong friends, but the word first means a rotating savings and mutual-aid group. Members pay a fixed sum at regular meetings and each member in turn receives the pot. It is recorded in the Ryukyu chronicle Kyūyō in 1733 as a way to save against famine, and it is still common. Many moai today are mainly social or drinking groups with small sums or none, and an Okinawa prefectural health official has linked frequent moai drinking gatherings to the island's heavy-drinking problem.
Yuimaru, or yuimaaru, is the Okinawan form of yui, reciprocal communal labour: neighbours help each other with planting or re-roofing and the help is returned. The saying "ichariba chōdē" is usually rendered as "once we meet, we are brothers and sisters". Together these describe a culture in which belonging and mutual obligation are part of daily life.
The village of Ōgimi in northern Okinawa became the symbol of this culture. On 23 April 1993 its senior citizens' club federation declared Ōgimi Japan's number-one longevity village and set up a stone monument, which now stands at the village's roadside station. In 2015 the village had about 418 residents aged 80 or older, roughly one in eight villagers, and 4 aged 100 or older.
Are blue zones real? The critique and the reply
The strongest critique comes from researcher Saul Justin Newman. In a preprint first posted in 2019, he showed that in the United States the introduction of birth certificates was associated with a 69–82 percent fall in records of people aged 110 and over, and that only 18 percent of "exhaustively" validated supercentenarians had a birth certificate. He also pointed out that the blue zones of Sardinia, Okinawa and Ikaria corresponded to regions with low income, low literacy and short life expectancy relative to their national averages. A 2024 preprint found implausible places, such as Western Sahara and Malawi, among the world's top regions for reaching 100. Newman received the 2024 Ig Nobel Prize in Demography for this work.
Blue-zone researchers answer that their ages were checked individually. In 2025 Steven Austad and Gianni Pes argued in The Gerontologist that blue-zone ages were validated by cross-checking several independent documentary sources and are reliable, and the 2008 Okinawa validation study reached the same conclusion for Okinawa.
A fair reading is this: individual age validation in Sardinia and Okinawa has been published in peer-reviewed journals, Newman's population-level critique is in preprints, and the debate is open. Separately and beyond dispute, Okinawa's life expectancy today is no longer exceptional within Japan.
Blue zones and ikigai: what you can take from them
Purpose sits on every list of blue-zone traits, and in Okinawa it has a name: ikigai, the Japanese sense that life is worth living. Here the research is more direct than for any single habit. In the Ohsaki Study of 43,391 Japanese adults, people who said they had no ikigai had a 1.5 times higher risk of dying over seven years than those who had it, after adjustment for other factors. That is an association, not proof that ikigai adds years, but it is a consistent finding across Japanese cohorts.
What the blue zones offer, then, is not a diet to copy but a way of looking at an ordinary week: how much of it involves moving without effort, belonging to people who rely on you, and doing something that feels worth getting up for. Those are things you can examine in your own life today, whatever the outcome of the debate about centenarian records.
A practical start is to ask which of these is weakest for you right now: daily joy, a sense of direction, or the feeling that you matter to others. That is exactly what the ikigai test on this site measures in two minutes.
Questions people ask
What are the 5 blue zones?
The five regions usually listed are the Barbagia area of Sardinia (Italy), Ikaria (Greece), the Nicoya Peninsula (Costa Rica), the Seventh-day Adventist community of Loma Linda (California, USA) and Okinawa (Japan). The list comes from Blue Zones LLC, built around Dan Buettner's work.
Who came up with the term blue zone?
Demographer Michel Poulain and physician Gianni Pes. In a study published in 2004 they marked an area of exceptional male longevity in central-eastern Sardinia in blue on their map. Dan Buettner later popularised the term.
Is Okinawa still a blue zone?
It is still on the list, but its numbers have changed. Okinawan men fell from 1st among Japan's 47 prefectures in life expectancy in 1980 and 1985 to 43rd in 2020, and Okinawa fell from 1st to 37th in centenarians per 100,000 by 2025. The famous longevity belongs mainly to the pre-war generation.
What did people in Okinawa eat?
In 1949 Okinawans ate about 1,785 kilocalories a day, with sweet potato as the staple supplying roughly 69 percent of calories in the Willcox brothers' breakdown, plus rice, other grains, soy and very little fish or meat. That traditional diet has largely disappeared since the war and the island's return to Japan in 1972.
Are blue zones a myth?
Not entirely, but they are debated. Age records in Sardinia and Okinawa were validated in peer-reviewed studies, while researcher Saul Newman argues in preprints that many extreme-age records reflect poor documentation. The 2025 scoping review found supporting evidence for Sardinia, Okinawa and Nicoya and none for Loma Linda.
What is the Power 9?
"Power 9" is a registered trademark of Blue Zones LLC for nine lifestyle lessons drawn from the regions, such as moving naturally, having a purpose, eating mostly plants and belonging to a community. It is a journalistic summary, not a result of a controlled study.
What is a moai in Okinawa?
A moai is a rotating savings and mutual-aid group: members pay a fixed sum at regular meetings and each in turn receives the pot. It is recorded in Ryukyu sources from 1733. Today many moai are also social circles of friends, which is the form popular books describe.
What is the village of Ōgimi known for?
Ōgimi in northern Okinawa declared itself Japan's number-one longevity village on 23 April 1993 and set up a stone monument. In 2015 about 418 of its residents were aged 80 or older and 4 were 100 or older. There is no verified current ranking that makes it the world's oldest village.
Can you live longer by copying blue zone habits?
No study has tested the blue-zone lifestyle as a package and shown that it adds years. The regions show that certain ways of living were common among very long-lived people; individual habits such as regular movement and social connection are studied separately in other research.
How are blue zones connected to ikigai?
Purpose is one of the traits described in every blue zone, and in Okinawa it is called ikigai. Japanese cohort studies, such as the Ohsaki Study of 43,391 adults, link having ikigai with lower mortality risk, which is an association rather than proof of cause.
- Poulain M., Pes G. M., Grasland C., et al. Identification of a geographic area characterized by extreme longevity in the Sardinia island: the AKEA study. Experimental Gerontology, 2004, 39 (9), 1423–1429.
- Buettner D. The Secrets of Long Life. National Geographic, November 2005; Buettner D. The Blue Zones: Lessons for Living Longer From the People Who've Lived the Longest. National Geographic, 2008.
- Candal-Pedreira C., et al. Blue Zones, an Analysis of Existing Evidence through a Scoping Review. Aging and Disease, 2025.
- Willcox D. C., Willcox B. J., Hsueh W. C., Suzuki M. Genetic determinants of exceptional human longevity: insights from the Okinawa Centenarian Study. Age, 2006, 28 (4), 313–332.
- Willcox D. C., Willcox B. J., He Q., Wang N. C., Suzuki M. They really are that old: a validation study of centenarian prevalence in Okinawa. Journals of Gerontology A, 2008, 63 (4), 338–349.
- Willcox B. J., Willcox D. C., Todoriki H., et al. Caloric restriction, the traditional Okinawan diet, and healthy aging. Annals of the New York Academy of Sciences, 2007, 1114, 434–455.
- Willcox D. C., Scapagnini G., Willcox B. J. Healthy aging diets other than the Mediterranean: a focus on the Okinawan diet. Mechanisms of Ageing and Development, 2014, 136–137, 148–162.
- Ministry of Health, Labour and Welfare of Japan. Prefectural life tables 2020 (令和2年都道府県別生命表の概況); centenarian statistics 2025–2026.
- Newman S. J. Supercentenarian and remarkable age records exhibit patterns indicative of clerical errors and pension fraud. bioRxiv/medRxiv preprint (first posted 2019), doi 10.1101/704080; Newman S. J., medRxiv preprint 2024, doi 10.1101/2024.09.06.24313170.
- Austad S. N., Pes G. M. The validity of Blue Zones demography: a response to critiques. The Gerontologist, 2025, 65 (12), gnaf246.
- Sone T., Nakaya N., Ohmori K., et al. Sense of life worth living (ikigai) and mortality in Japan: Ohsaki Study. Psychosomatic Medicine, 2008, 70 (6), 709–715.
This page brings together the demographic studies behind the blue zones, Japan's official prefectural statistics and the published critique, each stated with its source and year. It describes what researchers observed and does not give diet or health advice.