What Does It Take to Live to 100 and Beyond?

A first-of-its-kind review by AUC researchers analyzed more than half a century of research on the world's oldest people and found that exceptional longevity is shaped by an interconnected mix of health behaviors, genetics and social factors.

The findings point to a simple but powerful shift in the way we think about longevity: Living longer is only part of the story. The real goal is to live longer while remaining well.

"For public health, the priority is to help more people remain healthy and independent as they get older, rather than focusing only on reaching an exceptional age."

"There is no single magic formula for living past 100, but people do not live this long by chance," said Shaima Ibrahim (MS ’14), a PhD candidate in the Department of Biological, Chemical and Global Health Sciences and pharmacologist who led the research study. “A lot of what we see in exceptional longevity is built over a lifetime. The habits, the way people think, how they cope with challenges, how active they stay and how they connect with others — all of these things matter.”

The scoping review, published in Discover Public Health in July 2026, examined the genetic, biological, lifestyle, psychological and environmental factors that may contribute to exceptional longevity among centenarians (100+), semi-supercentenarians (aged 105–109) and supercentenarians (aged 110+) from around the world. 

"It’s not just about adding more birthdays. It’s about being able to get up, move around, think clearly, interact with people and enjoy your life for as long as possible."

“As the global aging population increases and the number of centenarians around the world rises, understanding what allows some people to live longer, and remain healthy as they do, is becoming an increasingly urgent area of research,” said Sungsoo Chun, professor at AUC's Department of Biological, Chemical and Global Health Sciences and research supervisor.

The work is part of a broader effort at AUC to develop a common framework for studying centenarians and human longevity, bringing researchers working in different countries and disciplines into a more coordinated research effort. “For public health, the priority is to help more people remain healthy and independent as they get older, rather than focusing only on reaching an exceptional age,” said Chun. 

The Goal Isn’t Simply To Reach 100

Longevity research is increasingly moving beyond the question of how long people live to ask how well they live.

That distinction is at the heart of the AUC research.

“Healthspan is what really matters,” said Ibrahim. “It’s not just about adding more birthdays. It’s about being able to get up, move around, think clearly, interact with people and enjoy your life for as long as possible.”

Ibrahim and her colleagues searched thousands of papers before narrowing them down to 124 studies that investigated factors linked to exceptional longevity. Many of today's centenarians lived through the 1918 influenza pandemic and the two World Wars, raising questions about whether a lifetime of surviving major health and social upheavals might somehow contribute to resilience later in life.

“Good health and wellbeing are number one,” said Ibrahim. “When studying people who live exceptionally long, we found that they follow certain habits and practices they started when they were younger in their 20s or 30s, and kept following these practices throughout their life. For example, it’s rare that you find a centenarian who is a smoker or physically inactive.”

The researchers grouped the findings into several broad categories, from biology to behavior. 

Their results suggest that exceptionally long-lived people may age differently at the cellular level, with evidence of more efficient DNA repair and greater protection against age-related disease. Across populations, centenarians were also more likely to eat largely plant-based diets, stay active through everyday activities such as walking and gardening, avoid smoking and maintain strong social and family ties. Resilience and lower neuroticism also emerged as recurring themes.

Perhaps the most striking finding concerned not whether centenarians get sick but when. Many encounter  major age-related diseases much later in life — a phenomenon known as the “compression of morbidity.” The researchers describe three groups: “escapers,” who avoid major age-related disease; “delayers,” who develop it much later than average; and “survivors,” who develop disease earlier but live with it for years. “Surprisingly, the centenarian group did not seem to suffer COVID as badly. General symptoms were minimal compared to the regular seniors,” said Ibrahim. 

When studying centenarians, women seem to have three times higher chances of reaching 100+ compared to men. However, if they do, their overall health condition is weaker than men due to bone deterioration and other factors, the researchers found. 

The evidence is far from complete, the researchers caution.

“We are still learning what makes someone exceptionally long-lived,” said Chun. “There are many factors we still cannot measure or fully understand. The important thing is to bring these pieces together and continue studying them systematically.”

New Research for an Old Phenomenon

For AUC researchers, the value of studying centenarians is not simply understanding the rare individuals who reach 100 or 110. It is understanding what their lives can teach the rest of us.

"People will say, ‘We are going to age. Why try? We will all die eventually.’ Well, let’s die healthy. Let’s lead healthier, longer lives instead of living with illness."

Research on centenarians began in the 1970s but were mostly expensive feats concentrated in developing countries. When AUC launched its master’s and PhD programs in global public health, it officially became one of only two institutions in Egypt to offer this specific type of programming open to both physicians and non-physicians.

The Global Supercentenarian Cohort Network Study (GSCNS), a groundbreaking international research initiative launched and hosted by AUC, leads the global protocol to study exceptional longevity. Founded and led by Chun, the network serves as the first multi-country platform dedicated strictly to studying extreme longevity. A key question asked by AUC researchers is how to scale their research to different models of environments and lifestyles. 

“Egypt’s position as one of the Middle East’s largest and most influential societies could also give research conducted here a wider regional reach, particularly as other countries in the region confront the same demographic changes,” said Chun. 

Egypt, like much of the world, is entering an era of population aging, making questions about healthy longevity increasingly relevant to public health. The researchers hope that over the next decade, a better understanding of the factors associated with exceptional longevity could help inform everyday choices around diet, physical activity, social connection, and other aspects of health and wellbeing.

The researchers see the work as part of a broader effort to shift how societies think about aging, from simply extending life to preserving health and independence for as long as possible.

“We are all human beings. What works for people in Egypt works for people on the other side of the world. Social, community and dietary habits differ, but the scoping review has lessons that are applicable to the general public’s daily life,” said Ibrahim.

That does not mean everyone can — or should — try to replicate the life of a centenarian. Genetics, circumstances and chance all play a role. Instead, the research points toward behaviors that are broadly beneficial regardless of whether someone ultimately reaches 100.

Changing those habits is likely to be a gradual process. Centenarians who were part of the study didn’t know that they were going to live that long; most didn’t plan it. The next step will be to create a pilot test to determine whether the protocol is valid or not. Then the network intends to run a study spanning the next 30 years.

“My main vision now is to instill good health and wellbeing behavior and tactics to all of society: young and old. People who reached an exceptional age did not do so out of nowhere. They adopted practices and behaviors across a lifetime,” said Ibrahim. “People will say, ‘We are going to age. Why try? We will all die eventually.’ Well, let’s die healthy. Let’s lead healthier, longer lives instead of living with illness.”