A supercentenarian (sometimes hyphenated as super-centenarian) is someone who has lived to or passed their 110th birthday. This age is achieved by about one in 1,000 centenarians. Anderson et al. concluded that supercentenarians live a life typically free of major age-related diseases until shortly before maximum human lifespan is reached (~125 years).
In 2003, the Gerontology Research Group estimated that there were 300–450 living supercentenarians in the world (an estimate not updated as of 2017), while they had validated approximately 40 cases. Adding those mentioned in other sources results in over 100 cases. A study conducted in 2010 by the Max Planck Institute for Demographic Research found 663 validated cases of supercentenarians, living and dead, and showed that the countries with the highest total number (not frequency) of supercentenarians (in decreasing order) were the United States, Japan, England plus Wales, France, and Italy.
The term supercentenarian has been in existence since at least the nineteenth century. The term ultracentenarian has also been used to describe someone well over 100 — Norris McWhirter, editor of The Guinness Book of Records, used the word in correspondence with age claims researcher A. Ross Eckler Jr. in 1976, and it was further popularised in 1991 by William Strauss and Neil Howe in their book Generations. Meanwhile, semisupercentenarian has been used for the age range of 105–109 years. Early references to supercentenarian tend to mean simply "someone well over 100", but the 110-and-over cutoff is the accepted criterion of demographers.
While claims of extreme age have persisted from the earliest times in history, the earliest supercentenarian accepted by Guinness World Records is Dutchman Thomas Peters (reportedly 1745–1857). Scholars such as French demographer Jean-Marie Robine, however, consider Geert Adriaans Boomgaard, also of the Netherlands, who turned 110 in 1898, to be the first verifiable case, as the alleged evidence for Peters has apparently been lost. The evidence for the 112 years of Englishman William Hiseland (reportedly 1620–1733) does not meet the standards required by Guinness World Records. Norwegian Church records, the accuracy of which is subject to dispute, also show what appear to be several supercentenarians who lived in the south-central part of present-day Norway during the 16th and 17th centuries, including Johannes Torpe (1549–1664), and Knud Erlandson Etun (1659–1770), both residents of Valdres, Oppland, Norway.
In 1902, Margaret Ann Neve, born in 1792, became the first verified female supercentenarian. Jeanne Calment of France, who died in 1997 aged 122 years, 164 days, had the longest human lifespan documented. The oldest verified man ever recorded is Jiroemon Kimura of Japan, who died in 2013 aged 116 years and 54 days.
Over 1,500 supercentenarians have been documented in history. It is likely that more have lived, but the majority of claims to have lived to this age do not have sufficient documentary support to be validated. This is slowly changing as those born after birth registration was standardized in more countries and localities attain supercentenarian age.
Research on the morbidity of supercentenarians has found that they remain free of major age-related diseases (e.g., stroke, cardiovascular disease, dementia, cancer, Parkinson's disease, and diabetes) until the very end of life when they die of exhaustion of organ reserve, which is the ability to return organ function to homeostasis. About 10% of supercentenarians survive until the last 3 months of life without major age-related diseases, as compared to only 4% of semisupercentenarians and 3% of centenarians.
By measuring the biological age of various tissues from supercentenarians, researchers may be able to identify the nature of those that are protected from aging effects. According to a study of 30 different body parts from a 112-year-old female supercentenarian, along with younger controls, the cerebellum is protected from aging according to an epigenetic biomarker of tissue age known as the epigenetic clock — the reading is about 15 years younger than expected in a centenarian. These findings could explain why the cerebellum exhibits fewer neuropathological hallmarks of age-related dementia as compared to other brain regions.