rash of riveting headline In the past few months, it has warned of a growing infertility crisis in men due to a drop in sperm count. The shop has claimed that plastic is behind the death of the great sperm But it turns out that the truth about fertility can be much more complicated than that.
Researchers have suspected in the early 1990s that human sperm counts may have declined. But a 2017 study really changed the conversation. study in question, Refer to Levine et al. after the author. This was a meta-analysis of other study groups. Regarding the sperm count between 1973 and 2011, the analysis found that the sperm count in samples taken from Western men dropped by more than 50% during that time.
These remarkable findings sparked a media frenzy in the study’s publication. with headlines talking about sperm count.”can cause human extinctionOne of Levine’s co-authors, et al., paper Shanna Swan published. her own book this year It’s about the declining sperm phenomenon that has triggered a new wave of headlines. They argue that endocrine disruptors in plastics, chemicals and other products Most often blame the shaky nature.
“Simply put, we are living in an era of fertility calculations that have a resonant impact all over the world,” the book’s foreword reads. (Later chapters advise readers to leave household items such as mothballs, air fresheners, scented candles, and antibacterial soaps in the name of sperm health. and advise parents to throw away plastic bins for toys instead of baskets.) “If these The shocking trend remains unchanged. It is difficult to predict what the world will look like in a hundred years. What does this dramatic drop in sperm count mean if it remains on the current trajectory? Does it signal the beginning of the end of the human race—or are we on the verge of extinction?”
That’s enough to make everyone want to throw away all their Tupperware. See Maid’s story It’s a documentary and notes what we can expect for sperm to come. But other experts Said there was still a lot of work to be done before we sounded the alarm.
First of all, there is the question of whether we are experiencing large, dead sperm in modern times. In paper Some scientists published earlier this month in Human Fertility argue that most of the panic was caused by some structural problem in the Levine et al. study.
Marion Boulicault, one of the lead authors of the latest report, said: “The problem with this study is that the main underlying issues affecting overall sperm reduction research,” Boulicault stressed, said Levine et al. And the statistical analysis itself wasn’t wrong. However, she said, “the implicit hypothesis built into the research and seems so plausible that it’s invisible.”
One of the main points, Boulicault said, is that studies assumed that men in the 1970s had ideal sperm levels. She noted that there was no “Specific scientific evidence” for this. And it’s not acceptable enough to have a large number of sperm counts. Men can have them naturally and remain fertile. The current World Health Organization standard states that a “Low” sperm count There are less than 15 million sperm per milliliter of semen. In particular, the decrease in sperm count Levine, et al. documented a shift from an average of 99 million sperm per ml in 1970 to 47 million sperm per ml in early 2010. to the end of society as we know it men are still fertile They just use a little less ammunition.
I reached out to Swan to see if she had any comments on Boulicault and colleagues’ paper. Swan’s publicist sent me a quote back to her co-author Hagai Levine. another shop: “We are delighted that our article has sparked discussion and brought attention to the highly neglected male reproductive issue. The response paper did not add new information. Of course, facts and interpretations are always different.”
Another point that Boulicault and her co-authors pointed out was how the discussion about low sperm count was misshaped based on the original research that divided the results, Levine et al. The findings fall into “Western” (Europe, Australia, and North America) and “other” countries (basically, everywhere else is a cluster of disparate locations like Tanzania and China). The fact that there is a large sample of studies conducted in “Western” countries versus “other” countries and that the proportion of results is ineffective when compared.
But as a result of the messages raised by the media, there are crises only in developed countries. Which led to news reports that caused panic. which implied or express Foreseeing disaster for a very specific group of people specific lifestyle The relationship between “Western” and “white” in the public imagination also means that a subset of reactive media characters has put this narrative to life.
Conspiracy theorist Alex Jones linked Levine et al to the discovery with his own theory that lower sperm counts are caused by men’s preference for women, while far-right YouTuber and Proud Boys member Joe Biggs. said in the video responds to the study that “men [are] Changed from being an alpha male. to imprisonment, basically Wearing skinny jeans, a masculine figure, a little girl who is a woman.”
While conspiracy theorists have taken the conspiracy People concerned about the environment have linked the decline in sperm to the plastic pollution crisis. But the discovery of a small group in the non-western world Some of which came from countries such as India and China with severe levels of industrialization and pollution—a survey in Levine, et al. The study did not reflect the same decline in sperm count as a large Western cohort study. This does not mean that this group is not affected by anything that interferes with sperm. But more research on sperm count is urgently needed in every corner of the world.
Richard Sharpe, a professor at the University of Edinburgh’s MRC Center for Reproductive Health, said there was no scientifically inaccurate way to prove that sperm count had declined in the past. “Until we can invent time travel and go back to the male example from the past. And then compare it to what is being done in the same lab today—and we certainly wouldn’t do that—we certainly can’t be sure,” he said.
But Sharp, who called the new article on Human Fertility “ludicrous”, said he was “100% confident” that men across most of Europe would “do it.” And possibly other areas of the world are experiencing sperm counts today, which can cause problems for those men who try. to become pregnant with a female partner especially if the pair is older. Such is the case with many modern couples. This lower sperm level does not necessarily mean that a man is infertile. but lower sperm count means “It will take longer to get a partner pregnant. and in the modern social context, which is a recipe for couples’ infertility.”
But Sharpe also cautioned against panicking about plastics or making plastics play a huge role in what’s going on. Sharpe responded to Swan’s claims in her book that in his assessment Much of the research done on the effects of phthalates on reproductive health over the past few decades has shown that “There is no convincing evidence that these have any effect on humans,” he said. Many of these studies are based on animal exposure to high levels of plasticizers that humans have. low Revelations in our daily lives meanwhile Other studies, he said, include pregnant women living near industrial sites or the role of over-the-counter drugs such as Tylenol during pregnancy. were overlooked in comparison.
“The effects we see can be explained by the plastic itself. or modern lifestyle that makes us see those plastics,” he said. “We look under the wrong lamppost. What we are looking at is the low levels of chemicals we are exposed to. But on the other side of the scale We have found incredible use in pharmaceuticals that we experience over and over again.”
There are so many things that we don’t know how our bodies work. And if you get too into the internet world Everything can be a threat. since the plastic wrap Body lotion to overexposure in wet conditions. It is very clear that we will need to mobilize an army of researchers to find out what endocrine disruptors. industrial pollution and other aspects How does modern life affect us? But it’s always worth examining the forces that shape conversations about scientific research. In particular, research that provokes panic and forecasting headlines plays into a niche tropics.
And no matter what factor you are investigating in modern life. The conversation shows how difficult it is to design sound research on the effects of certain inputs on human fertility.
“What do you do? Give Tylenol a certain amount and wait 25 years to see if it affects your sperm count,” Sharp said. “Who’s going to give you money for that? The cards are stacked with researchers.”