A 2015 Stanford University study found that men who wear boxers during the day and sleep in the buff at night had 25 percent lower rates of damaged DNA in their sperm compared to those who wear tighty-whities day and night.
The team looked at data on 656 men who were seeking treatment at a fertility centre in American between 2000 and 2017, assessing the quality of their semen and asking the men to fill in questionnaires about their lifestyle, which included a question on whether they most frequently wore boxers, bikinis, briefs, or jockeys.
They sought to test the theory that briefs, being more constricting, raise scrotal temperature and have a negative effect on fertility.
Co-author Associate Professor Dr Jorge Chavarro at the Harvard T.H. Chan School of Public Health said: "We didn't have enough men in the study who wore no underwear to be able to make any meaningful comparisons".
Tight underwear decreases sperm count.
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. Therefore, to determine the cause of male infertility, you first analyze the amount and concentration of sperm.More news: Saudi Arabia's diplomatic dispute with Canada: An explainer
In order to improve your sperm production, you can try wearing loser underwear for improving your sperm production. "We're talking in the neighborhood of about 20 million sperm difference", he said.
The groundbreaking study is the largest of its kind to look into the truth of a long-held suspicion that tighter trousers such as Y-fronts or briefs affect a man's ability to father children.
The study was published on Wednesday in the journal Human Reproduction.
From time immemorial, the debate about the best underwear for men has divided men into two camps: the ones who favour tight briefs and the others who love shorts.
"Potentially switching from tight to loose might help some men who are on the lower edge of sperm production". If your testicles feel hot and squashed, it might be time to swap to boxers or get some jeans in a larger size. "There is a big difference between measuring aspects of sperm quality (as done in this study) and measuring fertility". "That's why you see seasonal variations in sperm count", he added. Other potentially confounding factors that were not taken into consideration included the type of pants worn, and the textile fabric of the underwear. Underwear choice had no effect on these other markers.
The findings suggest that this hormone kicks into gear when it needs to compensate for increasing scrotal temperatures and decreasing sperm counts in tight underwear.