Effect of different types of textile fabric on spermatogenesis: an experimental study.
Level 5 - mechanism / opinion, no new human data
Animal experimental study
PubMed 8279095 · doi:10.1007/BF00296839
What was done
Thirty-one dogs were allocated to wear loose-fitting cotton underpants (n = 12), loose-fitting polyester underpants (n = 12), or no underwear as controls (n = 7). Garments were worn continuously for 24 months, followed by a 12-month recovery period after removal. Semen characteristics (sperm count, motility, abnormal forms), testicular temperature, testicular biopsy histology, and serum hormones (testosterone, FSH, LH, prolactin) were monitored across the 36-month period.
What was found
In the polyester group, testicular temperature and serum hormone levels showed no significant changes (P > 0.05). By month 24, polyester-wearing dogs showed a significant decrease in sperm count and motile sperms, a significant increase in abnormal sperm forms (P < 0.001), and degenerative changes on testicular biopsy. After garment removal, semen parameters returned to normal in 10 dogs, while 2 remained oligozoospermic. Cotton and control groups showed no significant changes in any parameter over the 36 months (P > 0.05). Numerical values for sperm parameters and temperatures were not reported in the abstract.
Why it matters
This experimental model suggests that polyester fabric may negatively affect spermatogenesis through non-thermal mechanisms that are largely reversible upon cessation of exposure.
Limits
The study was conducted in a small canine cohort (31 dogs), limiting direct applicability to human clinical outcomes. Exact baseline and post-intervention numerical values are omitted from the abstract, and the hypothesized electrostatic mechanism was not directly measured or verified.
Cited by
- contradicts Wearing polyester underwear lowers testosterone levels.