The nine Melis siblings who reside on the Italian island of Sardinia have a total of 818 years among them. They are the oldest siblings in the world.

The oldest sibling, Consolata, is 104 years old, and will turn 105 on Wednesday. Mafalda, nicknamed "The Little One" by her siblings and 27 years younger than her sister, is a relatively youthful 78. In between them are Claudia, aged 99, Maria, 97, Antonio, 93, Concetta, 91, Adolfo, 89, Vitalio, 86, and Vitalia, 81. Consolata still goes to mass every week, cooks and feeds her goats. Adolfo, who narrowly escaped capture at the hands of Nazi soldiers during World War II, runs the neighborhood bar.

The Melis family is from the village of Persdasdefogu on the southeastern corner of the island, in the Olgliastra province. At least 2,500 centenarians have lived on the island since 1996.

Craig Glenday, the editor-in-chief of the Guinness Book of World Records, said to The Guardian, "To have such a large number of living siblings with an average age of more than 90 years is incredibly rare. We believe Ogliastra likely contains the highest number of centenarians per capita in the world."

Seven of the 70 people in the world known to be over the age of 110 are Italian. In fact, while the world's oldest person is Jiroemon Kimura, who is 114 and lives in Japan, the second-oldest person is an Italian-born woman. She now lives in the United States.

Within Sardinia, 371 people are over 100 – not bad for an island that only boasts 1.67 million people. In fact, for every 100,000 residents, 22 people are over the age of 100.

So what's their secret? According to the Melis family, minestrone soup plays a huge role. Scientists add that genetics, diet and lifestyle all play a role as well.

Luca Deiana, a professor at Sardinia's University of Sassari, said to The Guardian that the DNA of Sardinians, which has been well-preserved due to the resistance of invaders, is geared toward long lives. It is windy there, constantly changing the air that they breathe, and temperatures are mild. Because of the prevalence of shepherding and farming, people are very active.

They eat less carbohydrate-heavy pasta as compared to their neighbors in the peninsula, subsisting primarily on proteins from milk and cheese. They also eat few sweets, saving them for holidays.

Older Sardinians are also very well-respected in their communities. They live with their children during their old age. Claudia's daughter Marta, 79, lives with her.

The only drawback of life in Persdasdefogu is its placement on the edge of a military testing site, Salto di Quirra. The site is currently being investigated for claims that its pollutants contributed to a spike in cancer in area residents. But that claim is rebuffed by Adolfo, who says that his younger brother Antonio worked at the site for a quarter-century.

The huge family consists of the siblings, as well as their 150 children, grandchildren, and great-grandchildren. Consolata alone has nine living children, 14 grandchildren, and 25 great-grandchildren.

The large size of the family was recognized in 1940 by Benito Mussolini, the Fascist dictator during the war, who gave their mother Eleonora a Medal of Honor and certificate.