- Men who have smoked cannabis have higher sperm concentrations and counts and lower serum follicle-stimulating hormone (FSH) concentrations.
Why this matters
- These findings are not consistent with those of other studies, which show a negative effect of cannabis on testicular function.
- Researchers in this longitudinal study examined subfertile men (N=662).
- The researchers analyzed associations between cannabis smoking and semen parameters, as well as sperm DNA integrity and serum reproductive hormones.
- Funding: National Institute of Environmental Health Sciences.
- Men who had smoked cannabis (n=365) had a significantly higher sperm concentration (62.7 [95% CI, 56.0-70.3] million/mL) than never-smokers (n=297; 45.4 [95% CI, 38.6-53.3] million/mL) after adjustment for potential confounders such as tobacco smoking and cocaine use (P=.0003).
- Sperm concentration was similar between current (n=74; 59.5 [95% CI, 47.3-74.8] million/mL) and past cannabis smokers (n=291; 63.5 [95% CI, 56.1-72.0] million/mL; P=.60).
- Cannabis smokers had significantly lower FSH concentrations than never-smokers (95% CI, −27% to −4%), and there were no significant differences between current and past smokers (P=.53).
- Cannabis use was self-reported.
- Findings may reflect reverse causation or be dose-dependent.