A study spanning more than 100 years of historical records of human capabilities and performance suggests that it has.
The twentieth century was a period of significant increase in human lifespan, height and physical performance, owing in particular to nutritional, medical and scientific progress. But according to the latest conclusions of a multidisciplinary team in France, this trend could soon be coming to a close – if it hasn’t already.
A debate has been going on for decades between those who posit that there exist upper limits for traits such as human lifespan or physical feats and those who claim that life expectancy and sport records will continue to rise indefinitely.
A new study, led by Jean-François Toussaint from the Institute of Biomedical Research and Epidemiology of Sport, at Paris Descartes University, has revisited more than a century of available data on the evolution of physical performance (during the Olympic Games), longevity and human height in a way that factors in, for the first time, the biological and environmental aspects that shape these historical trends.
Until now, according to the authors, constraining parameters such as the inherent physical limitations of the human body, its design and its biology, as well as the inescapable phenomena of aging – and last but not least, the body’s interactions with the environment – had not been taken into consideration when plotting the evolution of these human traits. But when these parameters are integrated into the math, the maximum biological limits for height, age and physical abilities all appear to have plateaued during the last several decades. “These traits no longer increase, despite the continuous nutritional, medical and scientific progress. This suggests that modern societies have allowed our species to reach its limits. We are the first generation to become aware of these limitations”, write the authors in their paper, published in a recent issue of the journal Frontiers in Physiology.
The scientists predict that the effects of these plateaus will be, among others, a decreasing number of record-breaking in sports and the fact that people will not exceed the longest lifespan achieved until now (by French woman Jeanne Calment, who outlived her 122nd birthday).
And that’s not all, they add. Deteriorating global environmental conditions, such as climate change – which is mostly derived from human activities –, are deleterious to human health and to the environment. Therefore, they may even result in downward trends for these indicators of human capabilities in the future.
In an appeal to policymakers, the authors stress that the biggest challenge for the coming decades will not be to improve human performance beyond its biological limits, but to avoid the decline of these human achievements by ensuring that most of the population can be maintained close to those limits.
Ana Gerschenfeld works as a Science Writer at the Science Communication Office at the Champalimaud Neuroscience Programme
Edited by: Catarina Ramos(Science Communication office).