As the recreational cannabis market continues to grow and flourish globally, we are learning more and more about the plant, how it can benefit us and also how it affects us in ways we may not have anticipated.
A recent study in the journal Therapeutic Advances in Urology falls in the latter category, finding that men and people with testicles who smoke cannabis can expect a lower sperm count and higher likelihood of deformed sperm, though the sperm do have greater motility, or ability to move independently using metabolic energy.
The researchers evaluated semen analyses from men seeking infertility evaluations from July 2017 to April 2018. All participants completed a questionnaire, which included items regarding cannabis consumption.
Of the 409 men surveyed, 174 claimed to have tried cannabis at some point in their lives, and 17 percent identified themselves as current users. In comparison to men who had never used cannabis, current users were twice as likely to have abnormal sperm morphology, though the misshapen sperm were even more common among past users than current users. The study’s authors suggest this may be because of a “delayed negative effect of marijuana on sperm morphology.”
The study also reported that sperm count was down among past and current users, cannabis users three times as likely to suffer from low semen volume than participants who had never used cannabis.
Interestingly enough, though cannabis consumers past and present saw their sperm impacted by their use, the study shows that these participants had “significantly greater chances of sperm motility within WHO reference range and trended toward improved odds of normal progressive motility.”
The researchers say this suggests a partially pro-spermatogenic effect, which was observed in a previous study as well, though the mechanism that promotes the increased motility among sperm is still not apparent and requires further study.
That said, the research goes on to explain that, regardless of the increased sperm motility observed as a whole, reduced semen volume among cannabis users will often lead to reduction in total sperm motility; essentially, if there are less sperm cells, the motility will naturally fall along with the lower sperm count. The study authors ultimately say, because of this, men and people with testicles should avoid smoking cannabis if they are looking to conceive.
The researchers say that this study was limited, in that it took place at a single center in Washington State, where cannabis is legal for recreational use, and ultimately that limits how accurately the findings can be generalized for the entire US population.
They also did not ask participants about the use of other recreational drugs, like opiates, and admit that the literature would benefit from further studies incorporating other recreational drug use.
Other limitations of the study include that lack of collection of hormonal data and testicular function, the lack of inclusion of factors like diet and exercise and the researchers’ limited ability to standardize cannabis dosage and method of consumption.
This is not the only recent study that has looked toward the relationship between cannabis and sperm production. Research involving more than 1,200 recreational drug users found that regular cannabis consumption was associated with a 30 percent reduction in sperm count. However, another study in Massachusetts confirmed the opposite, that cannabis users tend to have a higher sperm count than those who had never tried it.
The data allows for more research and raises additional questions, but the researchers say as a whole, in combination with previously published reports, confirm that cannabis does indeed have an impact on the male reproductive system and sperm function.
“While this discourse continues, it is important to account for reporting bias, which may explain the discrepancies between studies, particularly given the legal status of marijuana in each site of study,” the authors note. “Additionally, the ability of patients to accurately recall marijuana usage, and for investigators to adequately quantify use, are also important limitations to this field of study. Significant breakthroughs in this area of study will require additional means of clarifying marijuana use, such as hair drug screening.”