Pot, Sperm and You: Sperm Toke Too

Posted on by Paul Turek, MD
Marijuana and Male Fertility
So pretty and so powerful (Courtesy: Esteban Lopez, Unsplash.com)

Surely pot isn’t as bad for you as is smoking or alcohol…right? Fully one-third of reproductive-age Americans have used pot in the last year, and it’s now legal in more than half of US states, so how unhealthy could it be? As a reproductive specialist, I’ve always been worried about pot, but lately I’ve become even more concerned. I’m worried not only about the health of pot users, but also of their kids!

Doobie Blues

As with tobacco use, pot use has clearly been shown to impact semen quality. Pot has also been associated with higher rates of developing testicular cancer, which is also not good for fertility. The latest research, using the newest tools in molecular medicine, now shows an effect of pot that goes far beyond sperm count.

Flick the Fattie

A nicely performed study recently examined whether pot use could alter the genetic package of sperm. For background, let me remind you that the sperm DNA payload isn’t like any other—the DNA of this cell is unique in that it’s passed to offspring. A liver cell just stays a liver cell all its life, but a sperm passes its DNA to new human beings. A big difference.

But I digress. The study asked whether regular cannabis use changes how sperm DNA is regulated. In other words, is the epigenetic oversight of sperm gene expression altered by pot? And if so, how? They compared the epigenetic profiles of sperm from regular cannabis users (defined as at least weekly use) to non-cannabis users. And they also compared those sperm profiles to those of rats fed THC, the active ingredient in pot.

Here’s what they found:

  • Confirming earlier research, sperm counts in pot users were significantly lower than non-users.
  • There was “substantial disruption” of sperm gene regulation in pot users when compared to non-users
  • The genomic areas most affected by pot use involve genes active in growth and development, pathways known to be altered with cancer.
  • The gene pathways altered by human cannabis use were similar to those found in THC exposed rats, making THC the prime suspect for the effect.

Reefer Sadness

So, extrapolating just a little from what we know about epigenetic dysregulation and human disease, it’s quite plausible that pot-exposed sperm could lead to male infertility, poor embryo development after fertilization, altered or lethal embryonic or fetal growth patterns, and even cancer development in offspring. Granted, this is all speculation, but as I said before, I am worried. The old adage “What you don’t know can’t hurt you” is certainly outdated today. For now, I agree with the study authors’ advice to stop pot completely at least 6 months before trying to conceive.