↑ Poulain, Michel; Herm, Anne; Pes, Gianni. The Blue Zones: areas of exceptional longevity around the world in: Vienna Yearbook of Population Research, vol. 11, 2013, p. 87–108. backup Quote: "...These populations succeeded in maintaining a traditional lifestyle implying an intense physical activity that extends beyond the age of 80, a reduced level of stress and intensive family and community support for their oldest olds as well as the consumption of locally produced food...Based on a strict validation method, the ages of Sardinian centenarians were thoroughly proven to be correct (Poulain et al. 2006)... [footnote 2:] The term was chosen simply because at the time the authors used a blue pen on a map to mark the villages with long-lived population... [definition:] In practice, a blue zone (BZ) is defined as a rather limited and homogenous geographical area where the population shares the same lifestyle and environment and its longevity has been proved to be exceptionally high. [] Other validated BZs have been found so far in Okinawa (Japan), on the Nicoya peninsula (Costa Rica) and on the island of Ikaria (Greece)...The extreme longevity area identified in Sardinia and named as Blue Zone (BZ) includes a group of 14 villages in Barbagia and Ogliastra, covering the highest mountain area of Sardinia.4...Starting from 2005, in cooperation with D. Buettner, a journalist writing for National Geographic, the BZ concept was extended to other relevant regions of the earth (Buettner 2012). Exceptional longevity at population level has been identified and validated so far in three other settings: the island of Okinawa in Japan, the peninsula of Nicoya in Costa Rica and the island of Ikaria in Greece (Figures 3)..."
