FT262


The myth

Wearing tight underwear (or trousers) can reduce male fertility by raising the temperature of the testes, and thus lowering the sperm count.


The "truth"

More than a decade ago, in their groundbreaking Are boxer shorts really better? A critical analysis of the role of underwear type in male subfertility, Munkelwitz and Gilbert of the State University of New York reported, in the Journal of Urology (1998 Oct; 160(4):1337), their study of 97 male volunteers who had been monitored while wearing jockey or boxer shorts. The scientists found “no difference in scrotal temperature depending on underwear type”. They concluded that it was “unlikely that underwear type has a significant effect on male fertility”. Other studies have shown similar results, but men trying to become fathers are still routinely advised to choose the loose knickers option. It’s often sugg­ested that this belief originated in a Dutch study which showed that wearing tight leather trousers and tight plastic underwear together (but not individually) affected sperm viability. Which raises the question: how many people, even in the Netherlands, does that effect?


Sources

'Cut and Thrust of Teen Life', Times Online, 17 June 2006
'Semen and Sperm Quality', netdoctor
'From Underwear to Infertility', ifitandhealthy
'Eight Surprising Fertility Facts', Discovery Health


Disclaimer
Most experts argue that any temperature difference caused by tight clothes would be insufficient to make a permanent difference to sperm count, if it made any at all. Most – but not all. And even some of those who think that the idea is basically balls, nonetheless say that it might make a difference in borderline cases