Scientists are concerned that society is facing a crisis of male infertility, as a new study revealed a sharp decline in testosterone levels in men over the past five decades.
Study Results
According to data presented at the annual meeting of the European Society of Human Reproduction and Embryology in London recently, the overall testosterone level in men has decreased by 54% between 1972 and 2019.
Possible Causes of Decline
Although the rise in obesity and diabetes is one cause, researchers believe that external factors also play a significant role. These include chemicals that disrupt the endocrine system, which may be present in household items, as well as global warming.
Expert Opinions
Professor Haggai Levin from the Hebrew University of Jerusalem's Hadassah School of Public Health and Medicine noted that there is a serious crisis in male reproductive health that is not receiving enough attention. He emphasized that the observed drop in total testosterone by more than 50% over this period reflects a trend of decreasing by more than 1% annually, which is a very strong trend.
Previously, the same team of researchers published work on a significant decrease in sperm count over the last 40 years. Meanwhile, US Health Secretary Robert F. Kennedy Jr. recently called the decline in male fertility an 'existential problem.'
Specialist Comments
Professor Channa Jayasena from Imperial College London, a consultant in reproductive endocrinology, stated that the latest observations regarding testosterone should serve as a 'necessary reality check.' He expressed his conviction that the health of the male reproductive system is deteriorating and appears to have been worsening over time.
Levin added that 'reproductive health is a very important indicator of overall health,' noting that people live in an environment that is not ideal for health due to exposure to chemicals, climate, and lifestyle.
Hormone and Health Relationship
The link between testosterone and men's health is complex and bidirectional. This hormone is critical for sperm production, libido, muscle growth, bone strength, mood, energy levels, and metabolism. Simultaneously, health problems such as obesity can lower testosterone levels because excess fat promotes the conversion of testosterone to estrogen.
It should also be noted that taking testosterone supplements remains a subject of medical debate, as they can paradoxically suppress the body's natural sperm production.
Seeking Solutions and Warnings
Jayasena suggested that obesity and diabetes might explain all these changes but insists on the need to determine whether external factors, beyond obesity and diabetes, are triggering these processes. However, it is currently unclear which specific environmental factors may be involved, as studies on air pollution and endocrine disruptors yield inconsistent results.
In light of this uncertainty, Levin called for the precautionary principle to be applied, stating that a 95% confidence level is not required. Instead, he believes that more effective ways must be found to protect the population from hazardous chemicals, which he feels is currently not being done well enough.

