Top News

Blue Zones have long been held as a classic example to people wanting to live longer and healthier lives. Despite some questioning whether the claims held up, many experts stuck by their beliefs that people living in some specific parts of the world not only lived longer but were also fitter going into old age.

Now a study has examined the truth behind the claims to see if they really to match up to reality. And after looking at the data, the experts have confirmed 'blue zones' really might hold the secret many would like to know.

So called "blue zones" are parts of the world where people have unusually long lives. There are also a high number of people aged 90 and above.

• Met Office tells Brits in 47 areas 'get emergency kit ready' for 13-hour warning
• Snow maps reveal blizzard will bury UK cities and bring 31 inches over 24 hours

While the idea of blue zones has been around for almost two decades, there have been questions over its accuracy with many of the residents' ages self-reported. Critics said rather than people actually living well into their 90s and beyond, this was in reality down to poor record-keeping or clerical errors.

However in the study, published in the journal The Gerontologist, scientists said their study had found that these areas not only had unusually large numbers of elderly people, but also many of these people had exceptional health and vigour, well into advanced age. The study examined places which were geographically defined and had an exceptionally high concentration of people living to at least 90 years old over the past 150 years, and records that could validate birth and death certificates.

Using this data, four regions – Sardinia, Okinawa, Ikaria, and Nicoya – stand out as having unusually high survival into later life. Steven N. Austad, co-author of the study and scientific director at the American Federation for Aging Research said: "While exaggeration of exceptional longevity may be rife in many parts of the world, the ages of people in these four classic Blue Zones have been extensively validated using the best techniques of modern demography. They still have much to teach the world about how to live a long, healthy life."

However the researchers also discovered that being a blue zone isn't guaranteed forever with two of the four already starting to lose their status. Okinawa and Nicoya are both seeing changes which are affecting the lives of their residents.

The Sardinian blue zone covers six villages in the east-central part of the island, a region called Ogliastra containing about 12,000 people. The percentage of centenarians among people born between 1880 and 1900 was approximately five times higher than in the rest of Europe, and three times higher than in Sardinia as a whole. That proportion has continued to increase since the original study.

Researchers validated the ages of every person over 90 by cross-checking civil and ecclesiastical archives. They also looked at family genealogies to rule out errors or identity mistakes.

There are about 8,000 people living on Ikaria, a small Greek island in the Aegean sea. It was first found to be a blue zone in 2009 when the percentage of residents aged 90 or over was approximately three times the national average.

The Japanese island was first reported to have a percentage of centenarians seven times higher than the rest of the country 50 years ago in 1976. However the researches found the island no longer meets blue zone requirements.

Those born before 1940 now fulfil the criteria. By 2006, the centenarian rate had fallen to only about twice that of the rest of Japan. The study said wars and increasing westernisation, much of it linked to the long-standing United States military presence on the island, appear to have eroded islanders' health.

The study found that Nicoya is another blue zone that appears to be losing its claim to longevity. Many men born before 1930 lived to reach the age of 100, while those born later are less likely to become centenarians.

Dr Austad said: "Examination of these men during the period 1990–2011 found that 60–69-year-old men were seven times as likely to reach the age of 100 years as Japanese males of approximately the same time period—a time at which Japan was the longest-lived country in the world"

The Nicoya blue zone spans five neighbouring cantons – Santa Cruz, Carrillo, Nicoya, Nandayure, and Hojancha – in the northern part of the Nicoya Peninsula in Costa Rica. By 2010, new analyses found the original Nicoya blue zone had shrunk to about one-quarter of its original size. But it is not known why the numbers are falling.

However a new area of exceptional longevity has emerged. This covers three provinces in northern Costa Rica, near the Nicaraguan border. The expert added: "Investigation of changes in lifestyle factors as well as public health and medical changes in both of these areas will be illuminating."

Dr Austad said: "A common theme of these four classic Blue Zones is isolation. Three of the four (Sardinia, Ikaria, Okinawa) occupy all or part of islands, the fourth (Nicoya) lies on a peninsula that until recent times was difficult to access.

"The relative isolation of the islands is apparent in that each has evolved its own language or dialect relative to the mainland. Isolation makes possible cultural, and possibly genetic, uniqueness."

"Blue Zones provide an opportunity to study salubrious lifestyle factors in depth, " said Dr Austad. "They also offer an opportunity to evaluate how successfully (or not) traditional healthy lifestyles can interact with modernised infrastructure, public health policies, and medical practices. In some cases, adding modern medicine and infrastructure to traditional ways of life may extend and enhance Blue Zones, perhaps even creating new ones such as in northern Costa Rica.

"In other cases, as in Okinawa, modernisation might be fatal to a pre-existing exceptional health and longevity. Ultimately, Blue Zones stand as a beacon for global health and longevity. Embracing their lessons offers a promising path toward a longer, healthier future."