Tighty-whities have been the butt of jokes in sitcoms and TV for donkeys years now.
But if that isn’t enough to put men off of wearing them in favour of boxers, this new study just might.
Research into the effect of underwear on sperm quality has found that men who opt for airy boxer shorts made much more sperm than those who wore restrictive pairs.
That’s because they’re better at keeping your testicles cool, the researchers concluded.
Scientists at the Harvard T H Chan School of Public Health tested 656 men and found that those who wore boxers had 25% more sperm per millilitre and 17% in each ejaculate than those that wore briefs, jockeys or smaller pants.
The researchers explained in Human Reproduction how they quizzed men in couples who were seeking fertility treatment about their favourite underwear choices.
More than half (345) wore boxer shorts, and only a slightly smaller number of the group wore snugger-fitting underwear: 311.
After accounting for the men’s activity, smoking, body mass index and even if the men enjoyed hot baths, the researchers found consistent differences in their semen samples.
Importantly, while those differences were significant, none of the men had clinically low sperm counts – so while wearing looser boxers might be better for your sperm count, going for tighter ones wouldn’t necessarily make you infertile.
The study also doesn’t prove that tight underwear and a lower sperm count are tightly connected.
Men were asked to recall what underwear they prefer rather than actually being observed, and all of the men were seeking fertility treatment – so the findings might be have been different if other men had been involved in the test.
Other things weren’t taken into account either, such as how long they spend sitting down on a daily basis.
“The results from this study are very practical,” Lidia Mínguez-Alarcón, who worked on the study, told The Guardian.
“Men could improve their sperm production by easily changing their type of underwear.”
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