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In 1825, the British mathematician Benjamin Gompertz noticed a strange peculiarity about human aging and mortality: our risk of dying increases exponentially as we get older. Scientists now refer to this as the law of Gompertz mortality, and it has remained intact since it was documented nearly 200 years ago.
According to this law, at 50, for example, the risk of dying the next year is more than three times that of 30 years. As the 60s and 70s approached, our chances of dying doubled every 8 years.
It is considered an inescapable fact of life: the older you get, the greater the probability of dying. But recent research suggests that mortality rates stabilize after a certain age and indicate that there is no limit to the expectation of human life.
According to the study, the risk of dying is stabilized at the time of death. 105 years This means that a 106 year old has the same probability of living up to 107 years as a 112 year old person
The study found that mortality rates , which increase exponentially in adulthood, begin to slow down after the age of 80. years and they seem to stagnate or even decrease slightly after 105 years. At this point, the chances of dying in a given year are about 50-50.
Surveys of laboratory animals, such as fruit flies and nematodes, show mortality trays, in which their chances of dying do not increase after a certain age. In the case of humans, this leveling of mortality risk has been difficult to demonstrate, in part because of the difficulty of obtaining accurate data on the elderly.
To overcome this limitation, researchers used data collected by the National Institute of Statistics of Italy (ISTAT) between 2009 and 2015. This unique dataset contains information recently collected and validated on the individual survival rates of all Italian residents over 105 years: a total of 3836 people, Based on the data collected, the researchers built their model, linking mortality by all causes with age. The resulting curve of 80 years was in good agreement with the Gompertz law, but after that the probability of mortality began to decrease and in 105 years it had reached a leveling point.
For both women and men, the possibility of dying at the age of 68 was about 2%; at 76, it was about 4%. At age 97, the probability has risen to about 30% and in 105 years the probability of death has reached 60%, but has remained stable beyond this value.
This analysis was purely statistical and demographic, therefore the authors did not provide any tangible or significant explanation for the leveling of observed mortality risk.
However, the authors believe that leveling can occur because fragile people die gradually, leaving only the most resistant. Many factors, including biological and genetic factors, are likely to account for their resistance, and the identification of these factors may suggest ways to increase survival among young people
Reference: The plateau of The longevity of the pioneers. Science, 2018. https://doi.org/10.1126/science.aat3119
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