Reaching your 100th birthday is an achievement most of us can only dream about.
But what if we told you there’s an even more exclusive club, one with just 279 validated members worldwide, of people who’ve blown past that century mark and kept going well into their second century of life?
Scientists are studying Brazil’s remarkable supercentenarians, people who live beyond 110 years.
Their research has uncovered fascinating insights into what helps these extraordinary individuals not just survive but thrive.
And the answer might surprise you: it's all about having an immune system that refuses to act its age.
To understand just how remarkable these individuals are, consider this: only about one in 1,000 centenarians will ever reach the age of 110.
And overwhelmingly, about 90 per cent of these supercentenarians are women, reflecting the general pattern that women tend to outlive men by several years.
Right now, 116-year-old Ethel Caterham from Surrey holds the title of world's oldest living person, following the death of Brazilian nun Sister Inah in April 2025.
Meanwhile, Brazil's own João Marinho Neto, at 113, is the world's oldest living man.
But Brazil isn't just home to record-holders; it's becoming the world's most important laboratory for understanding extreme longevity.
The South American nation boasts an unusually high number of people living well past 110, making it a unique treasure trove for researchers trying to unlock the secrets of the human lifespan.
What makes Brazil so special in the longevity game? It turns out the country's rich history of colonisation dating back to the 1500s has created some of the most genetically diverse populations on Earth.
This genetic melting pot appears to offer protective advantages that help people not just live longer but live better.
The study continues with over 160 centenarians and 20 verified supercentenarians from across Brazil, providing a uniquely valuable group for research.
What's particularly striking is that many of these individuals have spent most of their lives in areas with limited access to modern healthcare, yet they've thrived.
'If there is a fountain of longevity out there, it's probably somewhere in Brazil.'
Dr Mayana Zatz, University of São Paulo
The really fascinating discovery centres on these supercentenarians' immune systems.
While most of us expect our immunity to decline with age, hello, more frequent colds and slower recovery times, these remarkable individuals have immune systems that behave more like those of people decades younger.
Their immune cells maintain incredibly efficient 'housekeeping' systems, constantly recycling proteins and clearing out cellular debris that would normally accumulate and cause problems.
It's like having a maintenance crew that never takes a day off, keeping everything in tip-top condition.
Even more intriguing, their immune systems show unusual adaptations.
Normally, CD4+ 'helper' T cells coordinate immune responses, while CD8+ 'killer' cells do the direct attacking of threats.
But in supercentenarians, the helper cells start behaving more like killer cells, a pattern rarely seen in younger people that seems to provide extra protection.
While we can't all inherit Brazil's unique genetic advantages, the research offers valuable insights into healthy ageing.
The key seems to be maintaining robust immune function throughout life, rather than simply trying to fix problems after they occur.
The Brazilian supercentenarians don't follow any particular diet, they're not all adhering to Mediterranean-style eating or special exercise regimens.
Instead, their advantage appears to be built into their biology, particularly their ability to avoid serious diseases rather than just survive them longer.
Previous research from Sweden has shown that people who live to 100 develop fewer serious diseases throughout their lives, accumulate health problems more slowly, and are much less likely to suffer major conditions like heart attacks, strokes, or dementia.
The Brazilian findings help explain why their immune systems are actively protecting them from disease development.
The research team is now working to develop cellular models that could help identify the specific biological mechanisms protecting Brazil's supercentenarians.
The ultimate goal? Understanding how healthy ageing might be extended to broader populations.
While we're still years away from practical applications, this research challenges the long-held belief that living longer inevitably means spending more years in poor health.
These Brazilian supercentenarians are proving that extreme longevity can come with quality of life maintained well into the second century.
For the moment, the best we can do is focus on maintaining our immune systems through proven strategies: regular exercise, adequate sleep, stress management, and staying up to date with vaccinations.
While we might not all make it to 110, we can certainly work towards ageing as gracefully as possible.
The work continues in Brazil, where researchers are building what may become the world's most important database of extreme human longevity.
Who knows? The secrets they uncover might just help the rest of us add not just years to our lives, but life to our years.
What aspects of healthy ageing are you most curious about? Have you noticed changes in your own immune system as you've aged? Share your thoughts and experiences in the comments below.
Abegail Abrugar