Men's Testosterone Levels Fell 54% From 1972 to 2019 as Scientists Warn of Fertility Crisis
Updated
Updated · The Guardian · Jul 8
Men's Testosterone Levels Fell 54% From 1972 to 2019 as Scientists Warn of Fertility Crisis
3 articles · Updated · The Guardian · Jul 8
Summary
A meta-analysis of 118,593 men across six longitudinal studies found total testosterone dropped 54% between 1972 and 2019, with the decline appearing to accelerate after 2000.
Researchers linked the fall primarily to obesity and diabetes, while also pointing to endocrine-disrupting chemicals and global heating as possible contributors to worsening male reproductive health.
Scientists said the evidence strengthens concerns over a broader fertility decline because testosterone helps regulate sperm production, sex drive, muscle mass, bone density, mood and metabolism.
The findings still face caveats: the studies controlled for age but not obesity, and some experts said obesity and diabetes alone could explain much or even all of the decline.
Doctors also warned against social-media promotion of testosterone supplements, noting they can suppress sperm production even as debate continues over the causes of the long-term drop.