Researchers show that "the possibility that human beings will be extinct" by decreasing the number of sperm

Based on research contents and data published so far,The number of male spermatozoa has been decreasing in recent decadesResearchers have shown the view that it is. There are also researchers who look skeptical about the claim that "the number of sperm is decreasing", but in the new research, nearly 200 research contents carried out in about 40 years were analyzed , Indicating that even if the current trend continues, there is even "the possibility of human beings becoming extinct".

Temporal trends in sperm count: a systematic review and meta-regression analysis | Human Reproduction Update | Oxford Academic
https://academic.oup.com/humupd/article-abstract/doi/10.1093/humupd/dmx022/4035689/Temporal-trends-in-sperm-count-a-systematic-review

Sperm count drop 'may lead to human extinction' - BBC News
http://www.bbc.com/news/health-40719743

Sperm counts among western men have halved in last 40 years - study | Life and style | The Guardian
https://www.theguardian.com/lifeandstyle/2017/jul/25/sperm-counts-among-western-men-have-halved-in-last-40-years-study

As a result of analyzing 185 studies conducted from 1973 to 2011, the concentration of semen of men living in North America, Europe, Australia, New Zealand has changed from 99 million / ml to 47.1 million / ml, and the annual average By decreasing by 1.4%, it turned out that it decreased by 52.4% within the investigation period. The total number of spermatozoa had decreased by 59.3%. In addition, this reduction rate is still continuing, and we know that there is an acceleration trend in some countries.

Hagai Levine who is the epidemiologist of the Hebrew University, who led the current study, the future when the "life of the ideal and the environment, and the current situation that has been exposed to a chemical substance did not change us, I I am worried. "" I will finally have problems of reproductive problems and extinction of mankind "to the BBC.

Meanwhile, there was no significant decrease in South America, Asia and Africa. However, in these countries researchers point out that the number of surveys underlying data itself is small, Levine concludes that eventually the number of spermatozoa in countries such as South America, Asia and Africa I am worried that it may decrease.

ByMichael Taggart Photography

However, while praising about the research itself, some experts look skeptical about the view that "humanity may be extinct". Among the studies that gave rise to the data are things that are not enough research results, such as those that are investigating a few men who visited infertility clinics as subjects. In addition, the result that "the number of sperm is decreasing" is easier to publish than the article "content of sperm is increasing", and the measurement method used in the initial study is sperm It is also pointed out that possibly overestimating the number of.

Like Professor Allan Pacey of the University of Sheffield, "I have not been convinced about a number of studies claiming that" the number of spermatozoa have been decreasing in recent years. "However, Levine's The research handled the defects of past research from the front, "some researchers said. Professor Pacey said that this research is "reducing the possibility of mistakes" while not discarding all mistakes, the survey results should be treated with caution.

Although the results of the research that "the number of sperm is decreasing" is still in the middle of discussion and there is no conclusion, this research is the first to clarify the direction of the contents of the survey to be done It can be said that it is a step. Although no clear cause of sperm reduction is known in previous studies, it shows relationships with chemical substances contained in agricultural chemicals, plastics, etc., and obesity, smoking, stress, diet, over-viewing of television It is. Mr. Levine identified the cause of spermic depletion and said, "We need to take action, such as by regulating artificial chemicals etc. And if we are not going to solve problems such as smoking and obesity I will not do it. "

BySteve Corey