Japan: A Super-Aged Society Leading in Longevity
For the 55th consecutive year, Japan has broken its own national record for centenarian population. The Health, Labour and Welfare Ministry announced in September 2025 that the country was home to 99,763 people aged 100 or older, with women comprising the vast majority at 88%. This consistently high number is a testament to Japan's public health advancements and societal changes over the past decades. The rapid rise in its elderly population is a major demographic trend, with experts noting that Japan is a frontrunner for other aging nations to learn from.
Absolute Number vs. Per Capita Rate
When discussing which country has the most centenarians, it is crucial to distinguish between the absolute number and the per capita rate. While some large, populous countries may have a high number of centenarians simply due to their overall population size, Japan also excels when looking at the proportion of centenarians per 100,000 people. This indicates a deeply ingrained societal and biological predisposition for longevity, rather than just a statistical artifact of its population size. For instance, a 2024 analysis showed Japan had approximately 80.6 centenarians per 100,000 people, a stark contrast to many other nations.
Factors Contributing to Japanese Longevity
Numerous factors contribute to Japan's success in supporting its aging population. Research and observations point to a combination of diet, healthcare, and social structures.
Diet and Lifestyle
- Nutrient-Dense Diet: The traditional Japanese diet is low in refined carbohydrates and rich in fish, vegetables, and whole grains. This eating pattern is associated with lower rates of chronic disease.
- Active Lifestyle: Okinawan studies, for example, have noted a culture of staying active into old age, with activities like gardening and walking playing significant roles.
Healthcare and Social Support
- Universal Health Coverage: Japan implemented universal medical insurance coverage in 1961, providing a safety net that has contributed to better health outcomes over generations.
- Robust Long-Term Care: The country's Long-Term Care Insurance (LTCI) system provides comprehensive support for those over 65, including home- and community-based care, reducing the burden on families and improving quality of life.
- Strong Community Bonds: The Okinawan study also highlighted the importance of a caring, supportive community that prevents isolation among older adults. Programs like the Silver Human Resource Center also help older adults stay engaged by matching them with temporary jobs.
A Comparative Look at Centenarian Populations
| Country | Latest Estimate (Year) | Absolute Number | Notes on Prevalence |
|---|---|---|---|
| Japan | 99,763 (2025) | ~100,000 | Highest rate per 100,000 people globally; consistently rising. |
| United States | 98,034 (2024) | ~98,000 | Quadrupled over recent decades; highest absolute number until surpassed by Japan. |
| China | 54,166 (2013) | ~54,000 | Smaller share of overall population, but projected to have the largest absolute number by 2054 due to massive population size,. |
| Italy | 21,211 (2024) | ~21,000 | Another aging society in Europe with a strong centenarian presence. |
| Thailand | 45,561 (2024) | ~45,000 | Higher per capita rate than many countries, demonstrating strong regional longevity. |
Looking Towards the Future
As global life expectancy increases, the number of centenarians worldwide is expected to grow dramatically. The United Nations has predicted a significant rise in centenarian populations in the coming decades. Projections from the Pew Research Center indicate a major shift, with China potentially having the largest number of centenarians by 2054, largely due to its enormous population size. However, countries like Japan will likely continue to lead in the proportion of their population reaching this milestone. This demographic shift presents both opportunities and challenges for healthcare, social security, and economic planning around the world.
The Health Profile of Centenarians
Research into centenarians provides valuable insights into the science of extreme longevity. Studies show that centenarians often delay or compress the onset of age-related diseases toward the very end of their lives, rather than experiencing a prolonged period of poor health.
- Delayers vs. Escapers: A 2024 study noted that a large percentage of centenarians were 'delayers,' meaning they were diagnosed with age-related diseases only after age 80. A smaller group, known as 'escapers,' had no major chronic disease at all.
- Robust Genetic Makeup: While lifestyle factors are critical, a genetic component to exceptional longevity is increasingly recognized. Researchers suggest that groups of genetic modifiers with modest effects can have a strong influence on reaching extreme ages.
- Unique Biological Markers: Comparisons of biological markers in centenarians often reveal lower levels of glucose, hemoglobin, and triglycerides compared to shorter-lived peers.
Conclusion
While the answer to which country has the most people over 100 years old? is definitively Japan, the broader story of centenarians is a global one. The increasing number of people reaching 100 is a triumph of public health, lifestyle choices, and genetic fortune. Japan's experience offers invaluable lessons for a world facing a rapidly aging population, demonstrating that a combination of a healthy diet, robust healthcare, and a supportive community can foster exceptional longevity. As researchers continue to study these remarkable individuals, we gain a deeper understanding of what it takes to not just live longer, but to live well. For further reading, explore the Pew Research Center's global demographic studies on centenarians.
