Among the myriad of physical insecurities that already plague the male mind – flabby abs, receding hairlines, penile insecurities – it appears young men may have yet another biological fear to contend with – the quality of their sperm.
On Monday, a paper published in the British Journal of Sports Medicineby researchers from Harvard School of Public Health brought to the forefront a continuing debate on whether or not the quality of men’s sperm has been declining in recent decades and, if so, for what reasons. The year-long study (2009-2010) found a negative association between watching TV and sperm count and concentration, while the opposite effect was observed with exercise.
Conducted at the University of Rochester in Rochester, New York, samples collected from 222 men between the ages of 18 and 22 were routinely analyzed and compared with self-reported exercise and TV-watching data. While there was no significant effect on sperm shape or movement speed, men who watched more than 14 hours of TV per week produced ejaculates of 44% lower sperm concentration than men who watched 4 hours of TV a week or less.
Furthermore, the sedentary behavior of men who watched TV for more than 14 hours a week seemed to modify the effects of moderate-to-vigorous physical activity on sperm concentration. Participants who watched 14 or more hours of TV per week, as well as engaged in moderate-to-vigorous physical activity for 4 hours or less per week, had the lowest sperm concentration of the subject group – 24 million sperm per milliliter – after controlling for race, BMI, diet and smoking habits.
However, before any young men rush to the couch and attempt to use the TV as a contraceptive, they should first be made aware of the implications of this modest change in sperm count. Conventionally, semen analysis is conducted for the primary purposes of understanding and improving fertility and artificial insemination. The significance of sperm count and sperm concentration is found in its direct link to male infertility. However, according to Richard Cone, spermatologist and Hopkins researcher of contraceptive design, the decrease in sperm count is small compared to what it takes to reduce fertility.
“[While it] might take a little longer to conceive, [it represents a largely] non-significant trend, not even approaching the level where fertility specialists would say ‘Uh oh! You don’t have enough sperm,’” Cone said.
The World Health Organization (WHO) currently classifies oligospermia, the medical term for low sperm concentration, as semen samples containing lower than 15 million sperm per milliliter. Thus, even after control adjustments, the men who produced the lowest concentration of sperm still had at least 6 million more sperm per milliliter, or approximately 40% more sperm, than an infertile man.
While the Harvard study has built upon past studies by extending the range of hours of physical activity and inactivity per week observed, whether or not TV-watching merits any concern in reproductive health is still in question. However, regardless of the fertility effects, the study stresses the health benefits of a physically active lifestyle to the male anatomy, which is always wise and effective advice to follow for any self-doubting men looking to curb their latest nagging pangs of a negative body-image.