This was determined by a statistical analysis published in the journal Science of the survival probability of about 4,000 people who reached the age of 105 or more.
A team of scientists, led by demographer Elizabeth Barbi from the University of Sapienza and statistician Francesco Lagon from the University of Roma Tre in Rome, concluded that the risk of death, which seems to increase with age, balances out after the age of 105, creating a kind of “mortality plateau” “.
According to scientists, since that time, the chances of someone dying before reaching their next birthday are half-and-half.
French demographer Jean-Marie Robin, who was not involved in the research, believes that if there is a balance in mortality, there is no limit to human longevity. Scientists have long debated whether there is an upper age limit to life in humans.
The consensus is that the risk of death increases systemically in adulthood, until about age eighty.
But there is great disagreement about what happens when people reach their ninetieth or hundredth year.
Some scientists have reexamined demographic data and concluded that there is a fixed, natural “expiry” of the human species and that the death rate continues to rise. Others have gone through the same data and concluded that the risk of death levels off at a very advanced age and that, accordingly, human lifespan has no upper limit. In 2016, a group of geneticists reopened that debate by analyzing the recorded ages of the world’s oldest individuals. They estimated that human longevity peaks at the age of 115. The group substantiated this with the example of only a few individuals who have lived the longest possible lifespan since the mid-nineties.
On the other hand, research published in various journals claims the same thing. According to Donald Roland, the world is facing a new global trend of increasing the number of old people, which will lead to a series of social changes worldwide. Namely, in 1950, no country had more than 11 percent of the population over 65 years old. In 2000, this number increased to 18 percent, and by 2050, scientists predict that as many as 38 percent of the total population will be older than the mentioned age. Only in the last quarter of the twentieth century, this number increased by a full six percent, while at the same time a serious decline in fertility was recorded. According to Roland, the world will soon have more pensioners than children, considering that they will make up as much as a quarter or a third of the number of nations.
In this connection, numerous economic studies were conducted that predicted a large burden on pension funds and calculated how many young, able-bodied people would have to work to support just one pensioner. However, not only pension funds will be affected by the aforementioned trend, but also healthcare, the economy, the working-age population and many other aspects of modern society.
Today, there are numerous definitions of age that most agree on. However, when it comes to the age limit and the criteria used to classify people in this category, there are different understandings in different countries on different continents.
The longest lifespan was recorded in the case of the French woman Jean Calme, who died in 1997 at the age of 122. In the study, scientists focused on a group of people aged 105 and older in Italy, the country with the highest percentage of very old people per capita. Thus, they avoided the problem of variation in data collection among different legal jurisdictions. Most believe that these data provide the best evidence for the onset of mortality balancing at very old ages in humans.
There are about 500,000 people in the world today who are 100 years old and older – a number that is expected to double every next decade. Even if mortality risk in later life remains flat, the growing number of people over 100 should continue to grow at a rate of one year per decade.
Scientists hope to better understand the causes of the decline in death rates in later life. Some of them believe that too few centenarians and older people are included in the analysis and that therefore the evidence for balancing mortality is not credible.
News and Science 
Leave a comment