Eight months ago, three researchers strongly shaken the foundations of the science of aging.
In an article published in the journal Nature (October 2016), three genetics from the new York medical Institute, albert Einstein argued that limit the duration of human life is 115 years old. With rare exceptions, such as Italian Emma Morano, who died in April this year at the age of 117 years, to live more than above period was not destined to anyone.
Of course, there is no denying that life expectancy has increased significantly over the last hundred years.
But does the same with a maximum life expectancy? In their study, Xiao Dong (Xiao Dong), Brandon Milholland (Brandon Milholland) and Yang Vig (Jan Vijg) argued that, despite increased life expectancy, the human body is designed for a certain maximum age, which, moreover, has reached its limit between 1995 and 1997. After that moment she stopped its growth on the basis of what the scientists have concluded that humanity had reached the natural age.
Last week British science magazine again addressed this issue by giving the floor to other scientists from different countries, which is bound to smash to smithereens of the authors. For this reason, the talk about the fact that the duration of human life is limited, seem frivolous.
The authors of the article in the journal Nature studied the age of death 534, break the 110-year milestone. “It is impossible to make any solid conclusions on the basis of such insufficient evidence,” — said the employee of the University of Groningen (the Netherlands) Nicholas brown (Nicholas Brown). He believes that the analysis and conclusions contained in the article, are invalid.
“The authors do not tell how they set the termination to increase the maximum lifespan,” says Hekimi Siegfried (Siegfried Hekimi) from McGill University in Montreal (Canada), a very critically minded in relation to the article in the journal Nature. Says Hekimi, all this indicates that the hypothesis of a maximum life of 115 years was the result of speculative observations. That is, the authors built a graph of the passing of the most famous centenarians and concluded that the maximum increase in life expectancy has stopped, and to live more than we, as a species, simply can not.
“It is very difficult to predict how long people will live in the distant future, if this limit exists. Three hundred years ago, many people lived very long by modern standards. If someone said that one day their descendants will be able to live 100 years, they would have thought we were crazy,” said Siegfried Hekimi.
Did not consider the factor of Jeanne calment
In 1997, the Frenchwoman Jeanne calment (Jeanne Calment) died at the age of 122 years. She was the oldest man ever lived on Earth, people whose dates of birth and death are documented. Born in 1875 in Arles (Arles) and smoked all his life. This fact, as critics believe, could have an adverse impact on the results of the study. “They claim that life expectancy has stopped increasing between 1995 and 1997, which died on Jeanne calment. If the authors conducted their study in 1980, then the maximum lifespan would they have still 111 years,” says Hekimi.
Dane Morten Rosing (Maarten Rozing), researcher, Center for healthy ageing at Copenhagen University, is very categorical in his explanation: “In 1968, Bob Beamon (Beamon, Bob) set a record in the long jump that lasted more than 20 years, until then, until it was broken by Mike Powell (Mike Powell),” explains Rosing.
If we apply here the same analytical principles of linear regression, which were used in the study of aging, separating the data before and after the establishment of a record (in this case, longevity), then we would come to the conclusion that after the record of Powell’s indicators jumpers fell. But “when we apply the same analysis to all the data, we see that there is a statistically significant growth of the long jump during the entire period of time.”
Contrary to biology
The same Rosing adds that “the knowledge which we now possess in the field of biology of aging, deny the assertion that the end of human life genetically programmed”, in this case for 115 years.
Added to the aforementioned increase in life expectancy. According to a Danish researcher, this “suggests that human aging is a much more flexible process than we previously thought, and the authors made a statistical error, making the erroneous conclusion that for a lifetime there is a limit and even lower, although in reality there is a possibility that it will continue to increase.”
Their own data contradict their claims
This controversial article not only attracted the attention of physicians and biologists. According to James Vaupel (James Vaupel), researcher of the Institute of the estate of max Planck (Germany), specializing in demography, work, published in the journal Nature last year, devoid of any meaning: “the Chart of life the world’s oldest men and women, since 1955, taken from the database group for the study of gerontology, indicates that the maximum human life span is increasing and there is no evidence that it has the limit.”
Dutch researcher Joop de beer (Joop de Beer) of the Interdisciplinary Institute of demography is even more categorical: “Even if in gerontology will not happen breakthrough, by 2070 Japanese women will live to be 118 years old.”
If the survival rate of people who have reached 100 years, will remain at the same level for the last 55 years, according to Dutch scientist, their number will increase from 56 thousand people in 2015 to 750 million by 2050. Of these, only one in a thousand will live another ten years, but the likelihood that some of the women-the inhabitant will overcome 120 years old by 2050, according to IAPA de beer, “high enough”.
Moreover, 840 out of every thousand women, which in 2015 was 70 years, one will live to be 125 in 2050.
“It’s hard to say. Three hundred years ago, many people lived very long by modern standards. If someone said that one day their descendants will be able to live 100 years, they would have thought we were crazy,” said Hakimi.
Canadian researchers re-analyzed the changes in life expectancy of people over the last 50 years and came to the conclusion that humanity has not yet reached the limit of the biologists from the United States said last year, according to a paper published in the journal Nature.
“It is very difficult to predict how long people will live in the distant future, if this limit exists. Three hundred years ago, many people lived very long by modern standards. If someone said that one day their descendants will be able to live 100 years, they would have thought we were crazy,” said Siegfried Hekimi (Siegfried Hekimi) from McGill University in Montreal (Canada).
The typical duration of human life before the birth of civilization ranged from 20 to 30 years and then rose steadily with the development of science and medicine. Today people live more than 60 years in several countries around the world, and over 80 years in Japan and other developed countries with high quality of life and excellent medicine.
On the other hand, for many organisms there is a maximum age at which most animals die from old age. In recent years, scientists actively debated whether it is for a person. In October last year, the American researchers said that a similar maximum age, perhaps, equal 100-115 years, and this is quite modest by the standards of the age of several biblical characters.
Hekimi and his colleagues cross-checked these findings, re-analyzing the statistics on life expectancy the most long-lived people in the US, the UK, France and Japan from 1968 to the present day.
They used the same technique as the authors statements about the existence of the limit of life: they were not interested in the number of deaths of people of a certain age, and that where the most notable decline in the number of deaths of people when comparing data in earlier and later years.
If the limit of life, this “hump of survival,” as it is called by scientists, is smoothly and continuously move in the direction of a more advanced age. If it exists, this “hump” will stop at a certain point and will not move further.
The lifting of the end of eternity
The problem, according to Hekimi, is that the number of centenarians, who were selected for the analysis of American biologists, was too small to draw firm conclusions. In addition, the authors of these statements have divided the dataset into two unequal parts — the period before 1994 and after. Only last a much shorter period of time — played a significant role in the quest for limit of life.
Hekimi and his colleagues have extended the dataset and analysed it as a whole, not divided into arbitrary segments. The analysis showed that growth and average and maximum life expectancy has not stopped during this time, American researchers were able to detect not the limit of life, and the traces of fluctuation in the maximum lifespan.
For example, something like Hekimi and his colleagues found at the beginning of this time span, from 1968 to 1980 when the maximum life expectancy also remained in place or even falling as in the last two decades. Accordingly, we can say that we have not yet reached the limit of life or that it does not exist in principle, the scientists conclude.
However, the discovery of the “limit of life” have already expressed their disagreement with the conclusions Hakimi. They believe that their opponents are using incorrect methods of analysis and incorrectly believe that the statistics on the maximum duration of life is subject to the same mathematical rules as sets of completely random values. Therefore, according to Yana Viga (Jan Vijg) and his colleagues from the University of new York (USA), their conclusions remain true, and the criticism Hakimi — unaddressed and incorrectly.