Coming back at this issue it seems possibly quite serious, it certainly seems underexamined.
I found this Vox article and the wikipedia page useful. It seems quite clear that there is quite a large drop in Western countries. That a similar drop isn’t seen in non-Western countries is especially telling.
The Vox article also points towards research into in-utero exposure to certain chemicals permanently decreasing sperm count. This also seems quite scary.
One of the scientists to first describe this phenomenon, Mount Sinai’s Shanna Swan, told Vox that these early chemical exposures have lifelong results. “The lowered androgen and alteration of development that happens in utero [results in] changes that are lifelong,” she said. “They are not correctable. Maybe in the future with genetic modification, you can alter a man’s germ cells that produce his sperm — but for now, if those are impacted adversely, a man will have a lowered sperm count his whole life.”
Separately, a March 2019 study found exposure to phthalates and polychlorinated biphenyl — again, two ingredients found in plastics — damaged the quality of sperm exposed to the chemicals.
This Forbes article is a typical piece about falling testosterone counts in men. Much is made of changing cultural mores, social expectations of men, etc. The biological component seems to get mentioned only in passing.
I found this article by urologists quite frightening. The effect size is eye-popping.
After controlling for confounders—including year of study, age, race, BMI, comorbidity status, alcohol and smoking use, and level of physical activity—total testosterone was lower among men in the later (2011-2016) versus earlier (1999-2000) cycles (P < 0.001). Mean total testosterone decreased from 1999-2000 (605.39 ng/dL), 2003-2004 (567.44 ng/dL), 2011-2012 (424.96 ng/dL), 2013-2014 (431.76 ng/dL), and 2015-2016 (451.22 ng/dL; all P < .0001).
Coming back at this issue it seems possibly quite serious, it certainly seems underexamined.
I found this Vox article and the wikipedia page useful. It seems quite clear that there is quite a large drop in Western countries. That a similar drop isn’t seen in non-Western countries is especially telling.
The Vox article also points towards research into in-utero exposure to certain chemicals permanently decreasing sperm count. This also seems quite scary.
This Forbes article is a typical piece about falling testosterone counts in men. Much is made of changing cultural mores, social expectations of men, etc. The biological component seems to get mentioned only in passing.
I found this article by urologists quite frightening. The effect size is eye-popping.