While the average human life lasts about seven decades, a few sturdy souls press on to become centenarians – people who live for at least a century. About 1 in 1,000 centenarians will survive an additional decade, earning the elite title of ' supercentenarian ' upon reaching their 110th birthday.
Scientists are understandably fascinated by these notable survivors, who may hold valuable secrets about longevity. Research has yielded lots of clues, including links to genes as well as to behavior and environment, but clear answers remain elusive.
That may be partly due to inadequate data, according to the authors of an ongoing longitudinal study on centenarians and supercentenarians in Brazil.
While Brazil's average life expectancy may not rival those of more notable countries like Japan or Italy, it does have a large portion of centenarians, the researchers note.
In a new viewpoint article, they synthesize recent discoveries about biological distinctions of centenarians – including data from their cohort in Brazil, where the abundance of centenarians in a genetically diverse population may offer key insights about human longevity.
Previous research has largely relied on genomic data from relatively homogenous populations, especially compared with Brazil.
With little representation from such diverse populations, there's a gap in our knowledge that could hinder efforts to find mechanisms behind longevity.
"This gap is especially limiting in longevity research, where admixed supercentenarians may harbor unique protective variants invisible in more genetically homogeneous populations," says first author and gerontologist Mateus Vidigal de Castro, a researcher at the Human Genome and Stem Cell Research Center in São Paulo.
Brazil's genetic diversity is among the world's highest, driven by a history of colonization, slavery, and immigration that led to extensive genetic admixture, or mixing of genetic material from other disparate populations.
This includes Indigenous people as well as Portuguese colonists who began arriving in 1500, but also millions of enslaved Africans taken to Brazil in the following centuries, plus waves of immigration from Europe, Japan, and elsewhere.
In a viewpoint and accompanying press release, de Castro and colleagues explain their ongoing research in Brazil.
They recruited from various regions across the country, forming a cohort of more than 160 centenarians, 20 of whom are supercentenarians. These include Inah Canabarro Lucas, a nun recognized as the oldest living person until her death in 2025 at age 116. The cohort also features two of Earth's oldest men, one of whom is reportedly now 113 years old.
Many participants not only survived to 100 but remained surprisingly capable.
"Notably, at the time of contact with our researchers, some Brazilian supercentenarians were lucid and independent in basic daily activities, such as feeding themselves," the study's authors write.
One family in the cohort boasted an incredible cluster of centenarians: a 110-year-old woman and her three nieces, aged 106, 104, and 100 at the time the viewpoint was published. Cases like this support existing evidence that longevity runs in families, and can help clarify differing influences on the length of a human life.
"Investigating such rare familial clusters offers a rare window into the polygenic inheritance of resilience and may help disentangle the genetic and epigenetic contributions to extreme longevity," de Castro says.
As previous research indicates, however, genes are just a piece of the puzzle, and lifestyle factors may play an even bigger role in determining longevity.
The new paper highlights recent insights about common traits of centenarians, such as a tendency for youthful-looking immune systems.
Many centenarians in the cohort hail from underserved regions of Brazil with limited access to medical treatment, hinting at protective mechanisms independent of modern health care.
Three Brazilian supercentenarians survived COVID-19 in 2020 before vaccines were available, for example, a feat the researchers attribute to robust immune function and undisturbed proteostasis.
The team continues to examine their data, both for contrast with less diverse populations and in hopes of discovering protective adaptations unique to Brazil.
To truly understand human longevity, and to ensure our insights help everyone, more research should focus on diverse populations like Brazil's, says co-author Mayana Zatz, a professor of genetics at the University of São Paulo.
"International longevity and genomics consortia should expand recruitment to include ancestrally diverse and admixed populations, such as Brazil's, or provide financial support for genomic, immunological, and longitudinal studies that deepen scientific insight and enhance equity in global health research," Zatz says.