The world's official oldest person is 115 years and 4 days old. Edna Parker lives in a retirement community in Shelbyville, Indiana, and was born on April 20, 1893. Parker was born on the same day as silent movie star Harold Lloyd. In the same retirement center also lives Sandy Allen, the tallest woman in the world.

Born in Morgan County, Indiana, Parker got a teaching certificate at Franklin College in 1911. She married her husband, Earl Parker, in 1913. She has outlived her husband (who died in 1938) and her two sons, and has 5 grandchildren, 11 great-grandchildren, and numerous great-great-grandchildren.

"We don't know why she's lived so long. But she's never been a worrier and she's always been a thin person, so maybe that has something to do with it," said Don Parker, her 59-year-old grandson.

A team from the New England Centenarian Study at Boston University took a blood sample from Parker in 2006 in a study gathering DNA information from supercentenarians (people who live to 110 and beyond).

"Her DNA is now preserved with samples of about 100 other people who made the 110-year milestone and whose genes are being analyzed. They're really our best bet for finding the elusive Holy Grail of our field -- which are these longevity-enabling genes," said project director Dr. Tom Perls.

"The key to a long life is now believed to be a mix of genetics and environmental factors such as health habits. Our research on about 1,500 centenarians suggests another factor that may protect people from illnesses such as heart attacks and stroke - they don't seem to dwell on stressful events," he added.

At the moment, only 75 people (64 women and 11 men) are recorded to be 110 or older. Japan holds the world record for average longevity, with about 28,000 persons aged over 100. This fact is attributed to the Japanese healthy alimentation and quality medical care. Japan possesses one of the longest average life spans, 85.3 years for women and 78.3 for men. The world's oldest man is also Japanese, Tomoji Tanabe, and is 111 years old, born September 18, 1895.

In fact, Parker "received" her title last year from a Japanese woman, Yone Minagawa, born on the 4 of January 1893. Unlike Mianagawa, whose state was relatively precarious (she moved around in a motorized wheelchair and did not hear well), Parker enjoys a better health.

The French woman Jeanne Calment, who died in 1997, aged 122, currently holds the world's absolute longevity record.

Speaking of records, the Guinness Book seems to include many slip-ups, as was the case back in 2007, when it was proven that the world's tallest human was in fact an Ukrainian man, and not a Chinese one. Two possible cases of people older than Parker have been signaled: the Ukrainian Hryhoriy Nestor, a bachelor from the Lviv region, who seems to have been born on the 15th March, 1891 (he died in December 2007); and a still living Palestinian woman, Mariam Amash, an inhabitant of the town of Jisr az-Zarqa, in northern Israel, who seems to be 120 years old, in conformity with a birth document delivered by the Turkish authorities ruling Palestine one century ago.