Why the world’s longevity hotspots may not be all they seem

Walk the shores of Ogliastra in Sardinia, an Italian island with crystal-clear waters and pink hillside flowers, and you’ll see families eating fresh fish, people working the land and older couples strolling the hills.

You might also see an unusual number of centenarians. This area of Italy is one of three Sardinian provinces that make up a Blue Zone – a handful of regions in the world with a disproportionately high number of exceptionally older people. These areas are highly prized by researchers keen to uncover the genetic and…