A study on longevity in Spanish regions has been conducted by Michel Poulain, a demographer and expert on 'zonas azules'. This research has resulted in the creation of a map showing the longevity rates of different regions in Spain. The map reveals significant differences in longevity across the country.

Some regions have a notably higher concentration of centenarians. Further details on the study and its findings are available from the source, El Mundo. The study's results can be found in El Mundo, which provides more information on the research and its conclusions regarding the longevity of Spanish regions, including the comparison of certain provinces such as Soria, La Rioja, and Segovia to others like Cádiz, Sevilla, and Málaga.