Your quest for a fuller head or larger muscles can make you infertile, according to experts.
They argue that body dysmorphic disorders and societal pressures may cause some men to take anabolic steroids (AAS), as described in their letter published in The Association for the Publication of the Journal of Internal Medicine. This theory, called the Mossman-Pacey Paradox, is named after the two researchers who described the phenomenon: James Mossman, Ph.D. Brown University, and Prof. Allan Pacey of the University of Sheffield. They also note that this paradox can be used in men who use medications such as finasteride to treat baldness.
Mossman was inspired to coined the term when he earned his doctorate at the University of Sheffield.
"I noticed that some men came to test their fertility, and these types were huge," Mossman told the BBC . "They really try to look big to look like the pinnacle of evolution, but they are evolutionarily very incompetent because, without exception, they did not have any sperm in their ejaculations."
This urge to become physically fit, despite the consequences, makes some men become anabolic steroids, they argue. That in turn makes guys less evolutionary fit.
There are currently no accurate data on steroid abuse in the United States, according to the National Institute of Health. However, the National Health Service in England believes that steroid abuse is a major cause of preventable male infertility.
"Evolutionary is no sperm = no baby = low fitness", Mossman and Pacey wrote in their letter. "In other words, many men have set themselves the unattainable goal of being both physically and evolutionarily fit when using AAS and bringing their masculinity and musculature into direct conflict."
Mossman and Pacey may have coined the term to describe the paradox, but it is important to note that they have not discovered the effects of steroid abuse or finasteride on fertility. It is well known that anabolic steroids reduce fertility by breaking the hormone signals required for the production of sperm, according to the Cleveland Clinic. And studies have shown that finasteride can cause erectile dysfunction and poor sperm quality, WebMD reported. In both cases, men can regain healthy sperm when they stop taking medication. Men who have taken steroids for long periods in high doses, however, can suffer irreversible damage.
However, Mossman and Pacey believe that there needs to be more education about the dangers of steroid abuse, especially in young men.
"It [steroid abuse] keeps coming up in clinics and the news is not going to young men that it's a problem, and some information could save them a lot of grief," Pacey said. BBC .