Humans may have peaked and climate change could be making things worse, scientists warn.
New research suggests humans may have reached their maximum limits for height, lifespan and physical performance, despite scientific advances being made in nutrition as well as curing and treating diseases.
Professor Jean-Francois Toussaint from Paris Descartes University, France, said: “These traits no longer increase, despite further 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 this.”
The team reviewed 120 years of historical information.
They believe anthropogenic activities – changes in climate and environment caused by human activity – could have a profound impact on human health and contribute to the plateau.
Prof Toussaint said: “This will be one of the biggest challenges of this century as the added pressure from anthropogenic activities will be responsible for damaging effects on human health and the environment.
“The current declines in human capacities we can see today are a sign that environmental changes, including climate, are already contributing to the increasing constraints we now have to consider.”
Rather than continually improving, we will see a shift in the proportion of the population reaching the previously recorded maximum limits, the researchers say.
They believe the effects of these plateaus could see a decrease in the number of sports records being broken.
Prof Toussaint added: “Observing decreasing tendencies may provide an early signal that something has changed but not for the better.
“Human height has decreased in the last decade in some African countries; this suggests some societies are no longer able to provide sufficient nutrition for each of their children and maintain the health of their younger inhabitants.”
The researchers are hoping their findings will encourage policymakers around the world to focus on strategies that can help increase the quality of life.
The study is published in the journal Frontiers in Physiology.