This week the UK press has been buzzing over a new study that finds that for men with infertility issues, lifestyle changes such as cutting smoking and alcohol don't make much of a difference. But avoiding tight-fitting underwear does. On Wednesday, the National Health Service issued a report that it hopes will clear the air, claiming the study's findings were "overblown" for hype.
"Before dads-to-be ponder the boxers-vs-briefs debate over a beer, a cigarette and a burger, it should be noted that the research behind today's attention-grabbing headlines does not suggest that unhealthy living is not detrimental to sperm quality," reports NHS.
The study -- carried out by researchers from the University of Manchester, the University of Sheffield and the University of Alberta in Canada -- looked at a very select group of men with fertility problems, and the findings indicate "very little about the general population or the effects of these vices." The reports adds: "Also, the study has not explored the reasons the men were experiencing fertility problems."
In the findings, researchers found no association between sperm motility and smoking, alcohol, recreational drug use or being overweight, although wearing tight underwear was associated with reduced sperm motility.
The researchers recruited 2,249 men from 14 fertility clinics around the UK. The men had been trying for a baby with their partner for at least 12 months. They filled in detailed questionnaires about their background and lifestyle and provided semen samples, which were examined for healthy sperm, or sperm that swim at normal speeds.
Around 40 in 100 men had a low number of healthy sperm -- but these men were no more likely to smoke, drink, use drugs, or be overweight than men with normal sperm count. However, they were more likely to work in manual labor and less likely to wear boxer shorts. The study appears in the journal Human Reproduction.
Previous studies have suggested that wearing tighter underwear could slow sperm production by raising the temperature of the testicles. WebMD cites that other research points to the chemicals used in manufacturing, building, and other types of manual work as possibly playing a role in reducing men's sperm count.