The world’s “blue zones”, which are home to an unusually high number of centenarians, keep changing every few years, according to a new study that may unravel the secret to long life.
These blue zones – Italy’s Sardinia, Japan’s Okinawa, Costa Rica’s Nicoya, Greece’s Ikaria – count among their inhabitants a disproportionately large number of people living into very old age, especially past 90.