The international team behind it says the data is alarming and points to a fertility crisis that threatens the very survival of humanity. Their meta-analysis looked at 223 studies based on sperm samples from more than 57,000 men in 53 countries. It shows for the first time that men in Latin America, Asia and Africa share a similar decline in total sperm count and concentration as previously observed in Europe, North America and Australia. The authors warn that the average sperm count has now fallen dangerously close to the limit that makes conception more difficult, meaning couples around the world may face problems having a baby without medical help. The findings, published Tuesday in the journal Human Reproduction Update, serve as a “canary in a coal mine,” said Professor Hagai Levine, lead author of the study from the Hadassah Braun School of Public Health at the Hebrew University of Jerusalem. “We have a serious problem on our hands which, if not mitigated, could threaten the survival of humanity,” he said in a statement.

50% reduction in sperm count

As part of a team that also includes Professor Shanna Swan at the Icahn School of Medicine in New York, along with researchers in Denmark, Brazil, Spain, Israel and the US, Levine studied sperm count trends in areas that were not previously reviewed. The same group had already reported in 2017 an alarming decline in sperm count across the Western world. In this latest study, they found that the average sperm count worldwide had dropped by over 50 percent over the past five decades. Data from 1973 to 2018 showed that sperm counts declined by an average of 1.2 percent per year. Data after the year 2000 showed a decline of more than 2.6 percent per year. “It’s just unbelievable. I couldn’t believe it myself,” Levine told Euronews Next. The fact that these findings were confirmed across the rest of the world points to a global crisis that could be compared to climate change, according to Levine. “As with climate change, the impact could be different in different places, but overall the phenomenon is global and should be treated as such,” he added. “It’s like a pandemic. It’s everywhere. And some of the causes may stay with us for a long time.”

Decreased chances of conception

The researchers say that while sperm counts are “an imperfect indicator of fertility,” they are closely related to fertility chances. They explain that above a threshold of 40-50 million/ml, a higher sperm count does not necessarily mean a higher chance of conception. On the other hand, below this threshold, the chance of conception decreases rapidly as the sperm count decreases. “At the population level, the drop in mean sperm count from 104 to 49 million/ml that we report here implies a significant increase in the proportion of men with delayed conception,” the study authors wrote. Professor Richard Sharpe, of the University of Edinburgh’s Center for Reproductive Health, called the findings “desperately bad news for couples’ fertility”, but also for aging nations more generally. “These issues are not just a problem for couples trying to have children, they are also a huge problem for society over the next 50 years, as fewer and fewer young people will be around to work and support the growing population of older people. ” he said. Although their research did not investigate the causes of this decline in sperm count, the authors say it reflects “a global crisis related to our modern environment and lifestyle” and point to the disruptive role of chemicals in hormonal and reproductive our system. They add that sperm count is also an indicator of men’s health, with low levels associated with an increased risk of chronic disease, testicular cancer and reduced lifespan. Dr Sarah Martins da Silva, senior lecturer in reproductive medicine at the University of Dundee, said she found it particularly worrying that the rate of decline in sperm counts had doubled since 2000 and called for more research into the reasons behind the trend. .
“The human race is not in immediate danger of extinction, but we really need research to understand why sperm counts are declining,” he said.
“Exposure to pollution, plastics, smoking, drugs and prescription drugs, as well as lifestyle, such as obesity and poor diet, have been suggested as contributing factors although the effects are poorly understood and unclear.”

The turning point for humanity?

The findings were published on a day when the world’s population passed the 8 billion mark, putting more pressure on the planet’s limited natural resources. “Philosophically, maybe lowering sperm count and infertility is somehow the world’s way of balancing out what’s going on,” Levine told Euronews Next. “But, you know, that’s just a thought. It’s not a scientific thought.” He said the findings should concern everyone — regardless of their views on how many human beings the planet needs right now. “Sperm count is a very good measure of global health and our future. And no matter how many people you think we need on Earth, you don’t want it to be determined by dangerous events rather than our own choices,” said Levine said. “I think we have to watch it very carefully at the global level, at the population level, at the local country level, as well as at the personal level,” he added, calling on authorities to improve lifestyles and limit human exposure to man-made chemicals through better setting. “Sometimes there’s a tipping point and the system collapses immediately. It means something is happening to our ecological systems, our reproductive systems — and at some point, it’s just too much.”