Which men’s underwear is best for healthy sperm? Science finds the answer

9 Aug 2018

Image: Dande_lion_studio/Shutterstock

Men fond of wearing tight underwear who are currently trying to conceive a child might want to think again following a new study.

In one of the largest studies of its kind, a team of researchers from the European Society of Human Reproduction and Embryology has analysed the link between what type of underwear a man wears and his semen quality.

As it turns out, those who wear boxer shorts were found to have higher sperm concentrations that those who opt for tighter-fitting underwear.

Publishing its findings in the journal Human Reproduction, the team asked 656 men seeking infertility treatment at one particular hospital between 2000 and 2017.

Unlike similar studies, this was the first to have a narrow focus on semen quality and include information on a variety of indicators of testicular function, such as reproductive hormones and sperm DNA damage.

Of the 656 men surveyed, 345 of them (53pc) said that they wore boxer shorts and were also typically younger, slimmer and more likely to take hot baths or Jacuzzis than those wearing tighter underwear.

The findings went on to show that the men who wore boxer shorts had a 25pc higher sperm concentration, 17pc higher sperm count and 33pc more sperm in a single ejaculate.

Body tries to compensate

Also, boxer shorts-wearing men were found to have lower levels of follicle-stimulating hormone (FSH) which stimulates sperm production.

The researchers said this likely shows FSH levels increase when it needs to compensate for testicular damage indicated by increasing scrotal temperatures, and decreasing sperm counts and concentration.

“We were able to find a potential compensatory mechanism whereby decreased sperm production relating to the type of underwear signals to the hypothalamus to increase secretion of gonadotropin, a hormone that acts on the testes and that is reflected by the increased levels of FSH, to try to increase sperm production,” said Dr Lidia Mínguez-Alarcón who led the study.

“This hypothesis requires confirmation by further research,” she added.

Such future research will also need to cater for the fact that these findings can’t be generalised for all men as those studied were attending a fertility centre.

Other factors that might affect scrotal heat – such as the type of trousers worn and underwear fabric – could also affect the results.

Mínguez-Alarcón concluded: “Since men can modify the type of underwear they choose to wear, these results may be useful to improve men’s testicular function.”

Colm Gorey was a senior journalist with Silicon Republic