It's long been suspected that the underwear men use and the positions they hold their bodies in can affect sperm quality, and now new research has backed up the notion that men should be free and unfettered in the interest of having children.
According to a recent study, men who wore boxer shorts during the day and nothing to bed had significantly lower levels of damaged DNA in their sperm compared to those who wore tight underpants during the day and at night.
"Among men in the general population attempting pregnancy, type of underwear worn during the day and to bed is associated with semen quality," said lead researcher Katherine Sapra of the US National Institute of Child Health and Human Development. "Reducing exposure for bed decreases DNA fragmentation; better semen quality parameters are observed in men wearing boxers during the day and none to bed."
The study tracked 500 men over the course of a year, taking note of the underwear choices they made and the quality of their sperm.
The researchers found that those who slept naked and wore loose-fitting boxers during the day experienced 25 percent less DNA fragmentation than those who opted for tight underwear like briefs. Although the sample size in the study was relatively small, it's further evidence that adopting a more liberal approach when it comes to undergarments could pose considerable health benefits for men's fertility.
"We have known for some time that men who increase the temperature of their testicles, either through the heat exposure at work or by wearing tight underwear, have poorer semen quality compared to men whose testicles are cooler," said Allan Pacey, a male fertility expert at Sheffield University in the UK, who was not involved with the study. "What has never adequately been shown is whether men can improve things by changing the choice of their underwear, but this study – although quite small – goes some way to suggest that is true."
Beyond merely analysing sperm quality, however, future research would offer even more valuable insight if it focused on quantifying the effects of a man's underwear choice. "What we really need to see is whether switching to looser underwear makes their partners get pregnant more often or quicker than they would have done had the men continued to wear tight underwear," he said.
But in the meantime, prospective dads – or men who simply want to look after the health of their sperm – have nothing to lose by adopting more flexible garb (or even going without entirely), knowing that in doing so, they may well be protecting their power to procreate.
"[S]witching underwear is hardly a risky thing to do," said Pacey, "so buying some looser pants might be good advice for would-be fathers."