The neutrality of this article is disputed. Relevant discussion may be found on the talk page. Please do not remove this message until conditions to do so are met. (October 2024) (Learn how and when to remove this message)

A blue zone is a region in the world where people are claimed to have exceptionally long lives beyond the age of 80 due to a lifestyle combining physical activity, low stress, rich social interactions, a local whole-foods diet, and low disease incidence.^[1] Examples of blue zones include Okinawa Prefecture, Japan; Nuoro Province, Sardinia, Italy; the Nicoya Peninsula, Costa Rica; and Icaria, Greece.^[1] The name "blue zones" derived simply during the original survey by scientists, who "used a blue pen on a map to mark the villages with long-lived population."^[2]

The concept of blue zones with longevity has been challenged by the absence of scientific evidence,^[3] and by the substantial decline of life expectancy during the 21st century in one of the first proposed blue zones, Okinawa.^[4]

A 1999 study of elderly people living on Sardinia found a prevalence of 13 centenarians per 100,000 population, indicating unusual longevity.^[5] A 2004 followup report showed that longevity was concentrated in the Nuoro province of Sardinia, specifically in its mountain regions where locally-born men lived longer than those in the rest of Sardinia, although reasons for the longevity were unknown.^[2]

Beginning in 2005 in collaboration with author Dan Buettner, the list of blue zone regions was extended from Sardinia to include Okinawa, Nicoya in Costa Rica, and Icaria in Greece.^[6]

Sardinia

Nicoya

Icaria

Loma Linda

Okinawa

class=notpageimage|

Proposed blue zones

In the original study of centenarians living in 14 mountain villages of Sardinia (the first proposed blue zone), the research team developed an Extreme Longevity Index (ELI) representing the ratio between the number of eventual centenarians born between 1880 and 1900, and the total number of births recorded during the same time interval for the region.^[2] The ELI was defined as the number of centenarians per 10,000 newborns, and was used to determine the probability that any person born in that municipality would reach 100 years old while remaining mentally and physically functional.^[2]

Another longevity index applied was the Centenarian rate (CR) for the 1900 birth group (number of persons surviving to 100 years old per 10,000 people alive at age 60) in December 2000.^[2] The Sardinia and Okinawa blue zones had CR values for men substantially higher compared to several other countries, whereas values for women were mostly above those in other countries, while comparable to others.^[2]

Several possible errors or limitations exist for these estimates, such as failure to validate accuracy of ages, unreliable interviews or missing birth records.^[2][6]

In 2008, Dan Buettner established the marketing company, Blue Zones LLC, adding Loma Linda, California, to the list of blue zones.^[7] Buettner described the Seventh-Day Adventist community there as having unusual longevity due putatively to a healthy lifestyle and plant-based diet.^[7][8] In 2020, the Blue Zones company was acquired by the Seventh-Day Adventist health care system, Adventist Health.^[9]

Recent years have seen the blue zone concept featured in initiatives in industries such as insurance, technology and tourism. ^[10]

The concept of blue zone communities having exceptional longevity has been challenged by the absence of evidence-based information.^[3]

It has also been questioned by the substantial decline of life expectancy during the 21st century in Okinawa, with the analysis concluding that "male longevity is now ranked 26th among the 47 prefectures of Japan".^[4] Michel Poulain, one of the authors of the original paper about blue zones, conducted a study in 2011 to validate the claims of longevity in Okinawa, and was unable to verify whether residents were as old as they reported due to many records not surviving World War II.^[6]

Costa Rica’s “Blue Zone” is now being re-examined and shown to be a result of cohort effects.^[11]

Harriet Hall, writing for Science-Based Medicine, stated that there are no controlled studies of elderly people in the blue zones, and that blue zone diets are based on speculation, not evidence through a rigorous scientific method.^[3]

• AARP/Blue Zones Vitality Project
• Alameda County Study
• Centenarian
• Gerontology Research Group
• Longevity
• Research into centenarians
• Supercentenarian

• Barclay, Eliza (11 April 2015). "Eating to Break 100: Longevity Diet Tips from the Blue Zones". The Salt. NPR. Retrieved 28 January 2022.
• Publications on longevity blue zones, Michel Poulain