Israeli Study Finds Men’s Testosterone Levels Have Dropped Over 50% in 50 Years
A new Israeli study presented at the European Society of Human Reproduction and Embryology (ESHRE) annual conference in London reveals that men’s total testosterone levels worldwide have declined by 54% between 1972 and 2019. This represents a consistent drop of over 1% per year. The research was led by Professor Hagai Levine, chair of the Israeli Public Health Physicians Association and a faculty member at the Hebrew University and Hadassah School of Public Health. He described the findings as a "significant reproductive health crisis" that has not received adequate attention.
Testosterone, the primary male sex hormone, plays a crucial role in sperm production, libido, muscle mass, bone density, energy levels, mood, and metabolism. Reduced testosterone levels can contribute to fertility issues, fatigue, muscle loss, and increased risk of metabolic diseases.
The study conducted a meta-analysis of six long-term studies involving 118,593 men from Israel, the United States, Brazil, Finland, and Denmark. Each study showed declining testosterone levels, with the decrease accelerating after 2000. Researchers suggest that rising obesity and diabetes rates partly explain the trend, as excess fat tissue converts testosterone into estrogen, lowering hormone levels. However, Professor Levine estimates that obesity and metabolic syndrome account for only 25% to 50% of the decline, indicating other environmental and behavioral factors may be involved.
These factors could include exposure to chemicals, climate change, diet, smoking, and physical inactivity. The research originated from Alon Levy’s master’s thesis in public health at Hebrew University. The authors emphasize the broader health implications beyond fertility and call for increased public health efforts to raise awareness about men’s reproductive health and reduce exposure to harmful substances. They also stress the need for further research to pinpoint the exact causes of the testosterone decline.
