"Blue zones" are areas of the world where people live considerably longer lives. On these territories we can find octogenarians, nonagenarians and many centenarians, and even some supercentenarians (people who have reached the age of 110).
These regions were named "blue zones" after the Belgian demographer Michel Poulain and the Italian doctor Gianni Pes discovered a population with such features in the region of Barbaglia (Sardinia, Italy), and they marked out the area with blue ink.
A demographic study carried out at the beginning of this century showed that one out of 196 people who were born between 1880 and 1990 reached the age of 100 years old.
Later on, the American researcher Dan Buettner embarked on a project aimed at identifying other areas with high longevity rates. He found four additional regions. These were also named "blue zones": Okinawa (Japan), Icaria (Greece), Loma Linda (California) and Nicoya Peninsula (Costa Rica). In all these territories there is a high proportion of long-lived people, and each area is characterised by specific features which relate to that condition.
In the region of Barbaglia, located in the Sardinian mountain area, there is the world's largest concentration of centenarians. Okinawa Island is inhabited by the oldest women on Earth. Icaria – an island which is located in the Aegean Sea – has the long-lived population with the lowest senile dementia levels. Loma Linda is home to a community of Seventh-day Adventists whose life expectancy is 10 years over the average lifespan in the United States. And in Nicoya we can find the second-largest community of centenarians in the world.