Ethical questions raised in search for Sardinian centenarians' secrets

There is something like gold flowing through the veins of 100-year-old Maria Tegas, and everyone wants a piece of the treasure.

The centenarian, who lives in a poor and remote area of central eastern Sardinia – in one of 14 villages known to geneticists and genealogists as the Blue Zone – has not had an easy life. Orphaned at the age of one, she remembers what it was like to go hungry, when homemade acorn bread was her main sustenance. As a young woman, she often walked 15 miles (24km) a day in steep and rocky terrain to bring food home to her six children.

“We lived like birds in the sky,” she says in a tiny whisper of a voice. Life got better, she says, when she began receiving welfare at the age of 50.

Tegas and hundreds of Sardinians like her have been considered a medical mystery since scientists started competing to find out why Blue Zone inhabitants have a life expectancy that is significantly higher than other Sardinians about 20 years ago.

For every 100,000...