A global drop in sperm counts, first noted in 2017, is accelerating, according to research showing the phenomenon seen in other parts of the world is also affecting men in South America, Asia and Africa.
The analysis, conducted by Professor Hagai Levine of the Hebrew University of Jerusalem and Professor Shanna Swan of the Icahn School of Medicine in New York, found that the world’s average sperm count more than halved between 1973 and 2018.
It has fallen by about 1 percent every year since 1972, the researchers said. Since 2000, however, the average annual decline has been more than 2.6 percent.
Levine said the results served “like a canary in a coal mine.” “We are dealing with a serious problem that, if not mitigated, could threaten the very survival of humanity,” he said.
The paper, published Tuesday in the journal Human Reproduction Update, was based on data from 53 countries and included statistics collected since the earlier study. It focused on sperm count trends in men in South America, Asia and Africa – regions not examined in the earlier report.
Men in these regions shared the significant declines in total sperm count and sperm concentration previously observed in North America, Europe and Australia, the researchers reported.
Levine said, “Overall, we are seeing a significant global decline in sperm counts of over 50 percent over the past 46 years, a decline that has accelerated in recent years.”
While the study didn’t examine the causes of these declines, Levine pointed to recent research suggesting that disorders in the development of the reproductive tract in utero were associated with “lifelong impairments in fertility and other markers of reproductive disorders.” He called for global action “to promote healthier environments for all species and reduce exposures and behaviors that threaten our reproductive health.”
Swan said the accelerating decline in global sperm counts means “more people need to use assisted reproduction to conceive.” The impact went beyond reduced fertility, as lower sperm counts were associated “with more diseases later in life — cardiovascular disease, diabetes and reproductive cancer — and a shorter life expectancy.”
The decline was too rapid to be due to genetic causes alone, she argued, pointing out that some risk factors for lower sperm counts are related to lifestyle factors such as diet, smoking, obesity, stress and binge drinking. However, she emphasized the role of environmental chemicals, particularly chemicals with the ability to affect the steroid hormones crucial for reproduction.
Most important were the “hormone-disrupting” chemicals that could alter testosterone and estrogen levels, like the phthalates – found in hundreds of cleaning and personal care products – and the bisphenols (BPA), which are often a component of containers used to Storage of food uses beverages such as bottled water. These are “crucially involved in reproductive function,” Swan added.
She urged men to avoid “smoking, a sedentary lifestyle, excessive weight gain, drug and alcohol abuse, and potentially toxic chemicals.”