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The Plateau of Human Mortality

12-07-2018

Is there a biological limit to human longevity? How is our risk of death correlated to ageing? In order to answer these questions, researchers from the Sapienza Department of Statistical Sciences, in collaboration with ISTAT – the Italian Statistics Institute and the Univesrities of Roma Tre, Berkeley and Southern Denmark, conducted a study on Italians aged between 105 and 110 to estimate their mortality risk. The results of the study, which have been published on Science, surprisingly indicated that those who are older than 105 reach a constant morality risk level.

This is the first time that a team of researchers has accurately, and with unprecedented precision, estimated the mortality rate for these very old individuals. “The analysed data, which has been carefully documented,” explains Sapienza Professor Elisabetta Barbi, “leads to the conclusion that the mortality curve rises exponentially until about we are 80, but then decelerates and reaches a plateauafter 105.” Moreover, the study also highlighted how our mortality risk slightly decreases even at such extreme ages. “If there is a limit to our longevity,” adds Professor Barbi, “it has not been reached, yet.”

Until today, the lack of reliable data on these “pioneers of longevity” has driven a controversial worldwide debate amongst scientists. In fact, the scientific community is divided amongst those who believe that the mortality risk curve continues to increase exponentially with age and those who believe it decelerates and eventually reaches a plateau at advanced ages, mimicking the behaviour of other animal species.

The discovery of this plateau is crucial to understanding the mechanisms that underlie senescence and human longevity. “This is an important confirmation for researchers in this field,” concludes Prof. Barbi, “of the importance of selective survival. It provides the necessary empirical data for the progress of studies on the evolutionary theory of senescence.”

 

References

The Plateau of Human Mortality: Demography of Longevity Pioneers - Elisabetta Barbi, Francesco Lagona, Marco Marsili, James W. Vaupel, Kenneth W. Wachter – Science, 29 Jun 2018: Vol. 360, Issue 6396, pp. 1459-1461 DOI: 10.1126/science.aat3119

For further information:

Elisabetta Barbi, Department of Statistical Sciences, Sapienza University 
elisabetta.barbi@uniroma1.it