India, Oct. 6 -- Some parts of the world are home to an unusually high number of people who live into their 90s and even past 100. These regions, popularly known as "Blue Zones," have attracted attention for their exceptionally high rates of longevity and relatively low rates of chronic disease.

The term "Blue Zone" was popularised by longevity researcher and author Dan Buettner, who worked with National Geographic, the National Institute on Ageing and other researchers to identify regions where people appeared to live exceptionally long lives. The name came from the blue circles researchers drew on maps while identifying these longevity hotspots.

India is not among the 5 traditionally recognised Blue Zones. According to the official si...