The first meta-analysis demonstrating declining sperm counts among men from South and Central America, Asia, and Africa was published by an international team 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, along with researchers in Denmark, Brazil, Spain, Israel, and the USA.
Alarmingly, this study also demonstrates that the reduction in sperm counts observed by this team in 2017 across North America, Europe, and Australia has persisted and even accelerated in the twenty-first century.
Sperm count is a measure of male health and human fertility, with low levels linked to a higher risk of chronic illness, testicular cancer, and a shorter life span. According to the authors, the decline is a reflection of a world crisis connected to our contemporary environment and lifestyle, which has significant implications for the survival of the human species.
This most recent study, which included information from 53 nations, was released in the journal Human Reproduction Update. It focuses on sperm count trends among men in previously unresearched regions, notably South America, Asia, and Africa, and adds an additional seven years of data collecting (2011–2018).
The information reveals, for the first time, that men in those regions share the marked reduction in total sperm counts (TSC) and sperm concentrations (SC) that were previously seen in North America, Europe, and Australia. Additionally, this analysis demonstrates a post-2000 acceleration in the global fall of TSC and SC.
“Overall, we’re witnessing a dramatic worldwide reduction in sperm counts of over 50% in the previous 46 years, a decline that has increased in recent years,” Levine said in summarising these findings.
Levine cited recent studies showing that disturbances in the development of the reproductive tract during foetal life are linked to lifetime impairment of fertility and other markers of reproductive dysfunction, despite the fact that the current study did not investigate the causes of sperm count declines.
Levine added that “environmental toxins and lifestyle choices are negatively influencing this prenatal development.”
Time is running out, cautioned Levine. “Our findings serve as a canary in a coal mine. We have a serious problem on our hands that, if not mitigated, could threaten humankind’s survival. We urgently call for global action to promote healthier environments for all species and reduce exposures and behaviours that threaten our reproductive health.”
Swan emphasised that low sperm counts have serious consequences for men’s health generally, have an impact on men’s fertility, and are associated with other troubling trends collectively known as testicular dysgenesis syndrome.
“According to our paper, men’s sperm concentration and total sperm counts are declining alarmingly at a rate of over 1% annually, which is consistent with declining female reproductive health and unfavourable trends in other men’s health outcomes like testicular cancer, hormonal imbalance, and genital birth defects. It is obvious that this cannot go on unchecked.”