Off with tight trunks and into boxers to be fit for fatherhood

MEN who wear boxer shorts have higher sperm concentrations than those who wear tight-fitting underwear, a study has found.

Scientists at Harvard said that swapping snug briefs for a roomier pair could be an easy way to improve sexual function.

Examinations of 656 men showed that those who primarily wore boxer shorts had a 25 per cent higher sperm concentration, 17 per cent higher total sperm count and 33 per cent more swimming sperm than men who wore tight-fitting underwear.

Boxer shorts-wearers also had lower levels of follicle-stimulating hormone, which kicks in to stimulate sperm production when things go wrong including through increased testicular temperatures.

Dr Lidia Mínguez-alarcón of Harvard Thchan School of Public Health said: “Since men can modify the type of underwear they choose to wear, these results may be useful to improve men’s testicular function.”

The study is the first to look at several measures of sexual function such as reproductive hormones and damage to DNA in sperm.

The men involved were aged between 18 and 56 and visited Massachusetts General Hospital between 2000 and 2017 as part of couples seeking fertility treatment. Each provided semen and blood samples and they were asked about the style of underwear they wore most frequently in the preceding three months. Although the men were attending hospital for fertility treatment, researchers said most had good semen quality compared with World Health Organization reference standards.

Allan Pacey, professor of andrology at the University of Sheffield, said: “This study confirms my long-held belief that men with poor sperm quality could potentially improve things by wearing looser underwear and keeping their testicles as cool as possible. There is no actual proof that switching underwear style will make any difference. However, I think it is a reasonable low cost and low-risk lifestyle change that men with poor sperm quality can undertake to potentially improve their semen quality.

“The study is not implying underpants are a major cause of infertility – in fact, fertility has not been measured. There is a big difference between measuring aspects of sperm quality (as done in this study) and measuring fertility.” The research was published in the journal Human Reproduction.

33pc The increase in the number of swimming sperm in samples from men who wore boxer shorts compared to briefs-wearers