A new US study has found that men who wear loose-fitting boxers have a significantly higher sperm count than those who wear other types of underwear.
Researchers at Havard University found that men who wore boxers had a 25 per cent higher sperm concentration and a 17 per cent greater sperm count than men wearing different forms of underwear, reports New Scientist.
The study, called Type of underwear worn and markers of testicular function among men attending a fertility center, involved getting 656 men to give a semen sample, before answering questions about what sort of underwear they wore the most in the last three months.
It also found out that boxer-wearing men had one third more swimming sperm in each ejaculation compared to those who wear different underwear.
Scientists made the findings taking into account external factors such as age, body mass, and smoking.
However, they said that there could be further factors that weren’t included in the study.
Jorge Chavarro, associate professor of nutrition and epidemiology at the university, led the study.
Chavarro told New Scientist that, although men who wear tight underwear have a lower sperm count, they generally still have sperm concentrations that fit in the average range.
“The men who may benefit most from paying attention to what type of underwear they’re wearing are men who are already having problems with fertility,” he said.
Sperm production is affected by temperature, and needs a cooler environment than in the nearby abdomen.
Chavarro pointed to previous studies that have shown how tight underwear can move the testes nearer to the abdomen, which increases the temperature in the scrotum.
The study also examined how different types of underwear affected reproductive hormone levels in men’s blood.
The abstract for the study concludes: “Men who reported most frequently wearing boxers had higher sperm concentration and total count, and lower FSH levels, compared to men who did not.”