Blue Zone, a Demographic Concept and Beyond

Abstract

The concept of Blue Zone (BZ) refers to regions with exceptionally high concentrations of centenarians, often in good health. Four BZs have been validated, Okinawa (Japan), Sardinia (Italy), Nicoya (Costa Rica), and Ikaria (Greece), with Martinique recently emerging as the fifth. Despite their popularity, BZs face criticism regarding data reliability, particularly the accuracy of centenarians' ages. This article reviews the process used to identify a BZ through a three-step methodology. First, it outlines the strict age validation procedures used to confirm longevity claims. Second, it reviews key demographic indicators to assess population longevity. Third, it defines BZ criteria, using the Sardinian BZ as a reference and requiring the eligible area to show a longevity level at least 50% higher than the national average. Martinique meets these criteria, while Galicia's validation is still ongoing. The study also highlights core longevity factors-diet, physical activity, social support, and environment-and underscores the importance of adopting the 7 BZ principles to foster longer, healthier lives worldwide. The BZ thus remains a valuable model for understanding the impact of lifestyle on aging and for applying these insights in public health and lifestyle medicine strategies.

Keywords: Blue Zone; age validation; centenarian; demographic concept; longevity.

Figure 1.

Spatial determination of the BZ in Sardinia based on the cohort born between 1880 and 1900 (left), and between 1907 and 1920 (right) (see Poulain et al. 2004 for the initial BZ, while the results on the new map elaborated by Claude Grasland are not yet published).

Figure 2.

Evolution of ELI for the generations born from 1907 to 1920 for the six areas under study (three years mobile averages). Detailed figures are proposed in Annex 2.