Wear boxers instead of briefs for higher sperm count: Study

Boxers or briefs may say a lot about a man’s personality, but new research says it also can predict their sperm count, with the loose-fitting underwear the better choice for more potent swimmers, according to research published Wednesday.

Researchers followed 656 men over 17 years and found that of those who wore boxers, they had a higher sperm concentration, total count of sperm and lower FSH, or follicle-stimulating hormone, levels (high counts can signal a problem with the pituitary gland).

The latest research is one of the only larger-scale projects to study a phenomenon inconsistent in the literature, the authors wrote in their study, which was published in the journal Human Reproduction.

They sought to test the theory that briefs, being more constricting, raise scrotal temperature and have a negative effect on fertility.

Dr. Jorge Chavarro, lead author of the study and associate professor of nutrition and epidemiology at Harvard, told NBC News their study confirms previous smaller-scale studies.

“We set out to take a deep, broad look at the effect of self-reported underwear choice on sperm,” he said. “What we saw is that type of underwear is related to semen quality. Guys who wear boxers had higher sperm concentration than men who wore more tightly fitting underwear.”