Harvard University researchers have done the most comprehensive study to date into the effect of underwear on sperm quality and found that the tighter the garment the lower the sperm count and concentration. It looked at 656 men who were part of couples seeking treatment at the clinic.
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 trousers. Lidia Mínguez-Alarcón, author and a research scientist at Harvard's T.H. Chan School of Public Health also said that this study provides science behind the recommendation for loose underwear to men who have fertility problems.
It's been suggested that 21st Century man is, reproductively speaking, only half the man his grandfather was.
It also found out that boxer-wearing men had one third more swimming sperm in each ejaculation compared to those who wear different underwear.
Although the men were attending hospital for fertility treatment, the researchers say most had good semen quality when compared to the World Health Organization's reference standards, and so the findings could be useful for all men.
"Men could improve their sperm production by easily changing their type of underwear". Higher levels of FSH indicate that the body is pushing the testes to produce more sperm as counts are low.
But if that isn't enough to put men off of wearing them in favour of boxers, this new study just might. 53% participants reported mostly wearing boxers. "There seems some compensation, but this compensation is not sufficient to bring them back to sperm counts of men who wear looser-fitting underwear".
The results showed that men who chose looser-fitting undergarments like boxers had a higher average sperm count and concentration than men who frequently wore briefs. It was published Wednesday in the journal Human Reproduction.
Dr. Jorge Chavarro, associate professor of nutrition and epidemiology at Harvard, lead author of the study has explained that tight underwear in men such as briefs can raise the scrotal temperatures and this can contribute to a lower sperm count and infertility.