Israeli-led study finds steep decline in sperm counts globally
An international study has found declining sperm counts among men around the world, reinforcing concerns of a looming fertility crisis.
Professor Hagai Levine
The team of researchers from Israel, the US, Denmark, Brazil and Spain was led by Professor Hagai Levine of the Hebrew University of Jerusalem’s Hadassah Braun School of Public Health, with Prof. Shanna Swan at the Icahn School of Medicine, Mount Sinai, New York. The team published its first meta-analysis in the peer-reviewed Human Reproduction Update on Tuesday.
The results showed declining sperm counts in North America, Europe and Australia and suggest the rate has accelerated since a previous study in 2017 by the same researchers.
Sperm count refers to the amount of sperm contained in an average ejaculation. For healthy males, this count may be as high as 200 million sperm per millilitre of semen. The World Health Organization considers 15 million sperm per millilitre of semen to be low.
The researchers found that while average sperm counts are currently 50 million and within normal parameters, the numbers have been dropping steadily since 1973 and may continue falling to less-than-optimal levels in future years.
The researchers stressed that sperm count is not only an indicator of human fertility but also is an indicator of men’s overall health. Low sperm levels are associated with an increased risk of chronic disease, testicular cancer and a decreased lifespan. The authors say the decline reflects a global crisis related to the environment and lifestyles, with broad implications for the survival of the human species.
“The troubling declines in men’s sperm concentration and total sperm counts at over one percent each year as reported in our paper are consistent with adverse trends in other men’s health outcomes, such as testicular cancer, hormonal disruption, and genital birth defects, as well as declines in female reproductive health,” Swan explained. “This clearly cannot continue unchecked.”
The study included an additional seven years of data collection (2011-2018) and focused on sperm count trends among men in regions not reviewed previously, specifically South America, Asia and Africa. The data showed, for the first time, that men in those regions share the significant decline in total sperm counts (TSC) and sperm concentration (SC) seen previously in North America, Europe and Australia.
Furthermore, this study shows an accelerated post-2000 decline in TSC and SC globally.
“Overall, we’re seeing a significant worldwide decline in sperm counts of over 50% in the past 46 years, a decline that has accelerated in recent years,” Levine said.
The current study did not examine the causes of sperm count declines, but Levine said recent research indicates that disturbances in the development of the reproductive tract during fetal life are linked to lifetime impairment of fertility and other markers of reproductive dysfunction.
Levine added that “lifestyle choices and chemicals in the environment are adversely affecting this fetal development.”
“Our findings serve as a canary in a coal mine. We have a serious problem on our hands that, if not mitigated, could threaten mankind’s survival. We urgently call for global action to promoted healthier environments for all species and reduce exposures and behaviors that threaten our reproductive health.”
Two or three children per couple is enough in our population crowded planet so no need to increasing the sperm counts. For believers, perhaps a declining sperm count is Gods way of controlling population growth.