Supercentenarian
A supercentenarian (sometimes hyphenated as super-centenarian) is a person who has reached the age of 110 years. This age is achieved by about one in 1,000 centenarians. Supercentenarians typically live a life free of major age-related diseases until shortly before the maximum human lifespan is reached. Incidence. The Gerontology Research Group maintains a top 30–40 list of oldest verified living people. The researchers estimate, based on a 0.15% to 0.25% survival rate of centenarians until the age of 110, that there should be between 300 and 450 living supercentenarians in the world. (See the List of the  oldest living people for a top 100 of verified ages.) A study conducted in 2010 by the Max Planck Institute for Demographic Research found 663 validated 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 first verified supercentenarian in human history was Dutchman Geert Adriaans Boomgaard (1788–1899), and it was not until the 1980s that the oldest verified age surpassed 115. Etymology. 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 popularized 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. History. 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 1620–1732) does not meet the standards required by Guinness World Records. Church of Norway 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. 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 man ever verified is Jiroemon Kimura of Japan, who died in 2013 aged 116 years and 54 days. Lucile Randon (born 11 February 1904) from France is the world's oldest living person, aged . Research into centenarians . Research into centenarians helps scientists understand how an ordinary person might live longer. Organisations that research centenarians and supercentenarians include the GRG and the Supercentenarian Research Foundation. In May 2021, whole-genome sequencing analysis of 81 Italian semi-supercentenarians and supercentenarians were published, along with 36 control group people from the same region who were simply of advanced age. Morbidity. 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 semi-supercentenarians 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 ageing 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 ageing, 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. A 2021 genomic study identified genetic characteristics that protect against age-related diseases, particularly variants that improve DNA repair. Five variants were found to be significant, affecting STK17A (increased expression) and COA1 (reduced expression) genes. Supercentenarians also had an unexpectedly low level of Somatic mutations.