Blue Zone

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 term, Blue Zones, is also used in marketing to promote a healthy lifestyle during aging. The concept of blue zones with longevity, however, has been challenged by the absence of scientific proof,[3] and by the substantial decline of life expectancy during the 21st century in one of the first proposed blue zones, Okinawa. https://en.wikipedia.org/wiki/Blue_zone

2023: Places claiming to be centenarian hotspots may just have bad data

Harriet Hall: "Blue Zones Diet: Speculation Based on Misinformation"