Is there a limit to human longevity? New data, new study
A new study published in Demographic Research by researchers from INED, the Université de Montréal, and INSERM enriches our knowledge on the question of human longevity. The authors’ analysis, based on French data from the International Database on Longevity (IDL) currently developed by INED, does not find a mortality “plateau” for human beings at extreme ages.
In 2016, geneticists published an article in Nature suggesting that the limit of human longevity was approximately 115 years (Dong et al. 2016). Two years later, in 2018, demographers using Italian data suggested the opposite in Science: no formal limits to the human lifespan (Barbi et al. 2018). Their study found essentially constant mortality rates beyond the age of 105, which led them to claim that a “mortality plateau” existed for human beings beyond that age (Figure 1). The existence of such a plateau meant, according to those authors, that after 105 years of life, mortality rates ceased being dependent on age and remained the same regardless of age. This in turn would seem to imply that there were no strict limits on human longevity, as the highest observed age values would depend only on the number of people reaching the plateau age.
New Data
The new study published in Demographic Research used rich, exceptionally reliable data from IDL (see box) to replicate the 2018 Italian study for the French population. It does not confirm the Italian findings; on the contrary, it suggests an increase in mortality rates after 105 years of age and finds nothing to indicate the existence of a mortality plateau. The authors confirm a significant disadvantage for men with regard to mortality but find no birthyear effect on the results (Figure 2). They therefore call for pursuing data collection, to provide material for later studies, and avoiding all hasty conclusions about mortality at extreme ages.
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IDL: THE INTERNATIONAL DATABASE ON LONGEVITY INED coordinates development of the IDL database, which comprises validated individual data on nearly 20,000 people who died at age 105 or over in 13 countries. The ultimate goal of IDL is to enable researchers to attain an exact measure of mortality at extremely old ages. |
Sources
Dang L.H.K., Camarda, C. G., Ouellette, N., Meslé, F., Robine, J.-M. and Vallin, J. (2023). The question of the human mortality plateau: Contrasting insights by longevity pioneers. Demographic Research, 48: 321–338.
On line:April 2023