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 lifestyle factors that influence longevity. But not everyone is convinced.

“The biggest secret of the Blue Zones is that they don’t exist,” says Saul Newman at University College London. Newman recently threw a wrench into decades of claims that centenarians can be found congregated in five Blue Zones. He says the data behind these claims can’t be validated and appears riddled with mistakes – and sometimes outright fraud. Demographers who have spent their careers investigating Blue Zones, and others who have created profitable business ventures around these regions, are hitting back against the claims.

The saga recently hit new lows. Relationships among the originators of the Blue Zone Project have disintegrated, and Science and The New York Times recently reported that a leading voice in the venture – journalist Dan Buettner, who wrote a 2005 National Geographic article that popularised the concept of Blue Zones – only included a location in the US to please his editor. However, Buettner has claimed he was misquoted on this point.

So, is there evidence that…