All things considered, Jose Aguinelo dos Santos is a pretty  lively Brazilian man. He walks without a stick, has no known health problems, smokes a pack of cigarettes a day, and is still a childless bachelor, according to reports. Oh, and he might be 126 years old—the world’s oldest living person.

That’s the claim being made by Vila Vicentina, the home for the poor and indigent where dos Santos lives.

Home staffers say that one of their most lucid residents has documents suggesting that his birth date was July 7, 1888. Two months before his purported birth, Brazil was the last country in the western hemisphere to abolish slavery. He was an infant when the country still had an imperial family.

Photos of dos Santos’sdocumentation and details of his story were first published by the Brazilian news service G1 on Sunday. The son of freed Afro-Brazilian slaves, dos Santos may have been born on a slave compound that he still vividly remembers. He was one of six children living in a community of former slaves with no beds, according to staff at the Vila Vicentina. His life’s work was manual labor on a coffee plantation in the Sao Paolo town of Bauru.

But to this day he still sings, tells jokes and has a reputation for being as stubborn as a mule.

“He's one of our most with-it residents,” Mariana Silva, a psychologist at the Vila Vicentina home, told the Telegraph. “He doesn't have high cholesterol, diabetes or high blood pressure. The only medicine he takes are vitamins and a tablet to give him an appetite, which you can lose with old age.”

"He doesn't like to take a bath every day and it's sometimes impossible to get him to the shower. When he puts his foot down, that's it. No one can get him in there," she added.

Currently, the oldest verified living person is 116-year old Misao Okawa of Japan, according to the Gerontology Research Group, an international organization which tracks and verifies “Supercentenarians” -- people who have lived to be older than 110. And dos Santos would be an outlier on the list for more than his notably advanced age. Only two of the 74 verified supercentenarians are men.

The process of verifying individuals who reach exceptionally old age relies on difficult to obtain documentation. GRG co-founder L. Stephen Coles told in a recent interview that his group requires up to three items of documentation to prove age, which could be a birth certificate or a baptismal record, along with a photo ID from a reliable government agency. 

Confirmed supercentenarians are interviewed and the group sometime takes blood samples from the people who are willing.

According to Coles, who is a University of California lecturer, the list GRG maintains probably vastly underestimates the true number of some of the world’s oldest people in places where documentation is scarce or non-existent:

While Japan has kept scrupulous birth records for more than a century (perhaps partly explaining why that country has so many supercentenarians per capita), other countries have historically been less meticulous about that task. Due to a general lack of written birth records in African nations, for example, Table E includes no one from that massive continent. Similarly, China certainly has many supercentenarians, but none are confirmed because the Chinese government did not track births prior to the early 1900s. India, likewise, did not keep such records until around 1903, when the British began tracking some births there—especially of eldest sons in landowner families. As a result, Coles expects that more and more Indians will join the list as years pass.

Even as people have begun living longer in general, our fascination with extreme ages hasn't waned.

Dos Santos, for example, is reportedly a long-time pack-a-day smoker, but also has no known medical problems. According to Thomas Perls, a professor of medicine and geriatrics at Boston Medical Center, and director of the New England Centenarian Study, people like him have almost nothing in common, except perhaps good genes.

“About 70 percent of average aging is in your hands with health-related behaviors,” Perls told “But if you get beyond 100, the tables turn and it’s more like 70 percent genetic and 30 percent behaviors.”

Dos Santos was issued a birth certificate and identity documents in 2001 after an extensive interview with a judge, according to Reuters.

But that is unlikely to be enough, the officials at dos Santos’s nursing home know.

They plan to use a carbon 14 dating procedure to more closely verify his age--an expensive proposition to the tune of $22,000.

"We are trying to find a way to do it without having to pay,” Jose Roberto Pires, the president of the retirement home, told the Telegraph. “This is very important. We believe the world's oldest ever person is living here with us, and this is the only way we can really prove it."

More likely, however, dos Santos’ claim is what Robert Young of the Gerontology Research Group calls a “longevity myth.”

Young, who is a senior consultant for gerontology for the Guinness World Records, said that the lack of original documentation, family history and a complete lack of long term evidence such as work or church history suggests that the claim is a “junk case.”

The maximum proven human lifespan is 122.45  years, and the odds of living to 126 are one trillion to one, Young said.

“A case like this is extremely, extremely, extremely unlikely to be true,” Young said in an email. “If we had all the data from around the world for everyone, it's likely that Brazil's oldest living person was born in 1899 and is 115 years old....and statistically should be a woman.”

[This post has been updated.]