The results of an international study involving the University of Murcia point to a significant decline in sperm count worldwide, especially since 2000.
In 2017, researchers from the University of Murcia (UMU) were already warning of male fertility problems in Europe, due to a decrease in sperm concentration among males.
Now, a new international study, in which the Public Health and Epidemiology research group of the University of Murcia (UMU) has participated, has also been carried out this study among men from South and Central America, Asia and Africa, which joins the data extracted from North America, Europe and Australia, to highlight not only the decrease in the number of sperm in all continents but also how this problem is accelerating during the 21st century.
This “emerging crisis”, as the authors themselves mention, is not only worrying in relation to male fertility, “it is also an indicator of the state of men’s health, with low levels associated with an increased risk of chronic diseases and testicular cancer,” says Jaime Mendiola, professor of Public Health at UMU. The authors also point out that this decline reflects a global crisis related to ongoing environmental degradation and society’s stressful pace of life, with wide-ranging implications for the survival of the human species.
A global problem
The results, just published in Human Reproduction Update, have been collected over the past seven years (2011-2018) with data from 53 countries, and focus on trends in sperm counts among males in regions not previously reviewed, specifically South America, Asia and Africa. The data show, for the first time, that men in these regions share a significant decline in sperm count and a reduction in sperm concentration, a reality previously observed in North America, Europe and Australia.
Moreover, this study shows that the decline has been much greater since the turn of the century. As Hagai Levine, lead researcher of the project, summarises: “Overall, we are seeing a significant global decline in sperm counts of more than 50% over the past 46 years, a decline that has accelerated in recent years.
As confirmed by Mendiola, a member of the international research team and co-author of the paper, “the studies analysed in Spain reflect a similar trend to that shown in the global study and show a decrease in total sperm count and sperm concentration”.
While the current work does not analyse the causes of the observed sperm decline, recent research indicates that alterations in the development of the reproductive tract during foetal life are associated with impaired fertility during adulthood, as well as other markers of reproductive dysfunction. In addition, Levine also associates that “certain lifestyle habits and chemical compounds in the environment are adversely affecting fetal development.”
“Our findings serve as the canary in the coal mine,” highlights the researcher from the Hadassah Braun School of Public Health in Jerusalem. “We have a serious problem on our hands that, if not mitigated, could threaten the survival of humanity. An urgent call for global action is needed to promote a healthier environment for all species and to reduce the exposures and behaviours that threaten our reproductive health.
Significant implications for men’s health
Professor Shanna Swan, co-director of the project and a researcher at the Icahn School of Medicine at Mount Sinai (New York, USA), pointed out that low sperm counts not only affect male fertility, but also have important consequences for overall male health, and are linked to other adverse trends, generically termed testicular dysgenesis syndrome.
“The disturbing decline in sperm counts and sperm concentration of more than 1% per year shown in our work are consistent with adverse trends in other male pathologies, such as testicular cancer, hormonal disruptions and genital birth defects, as well as declines in female reproductive health,” explains Swan.