Just as scientists have previously studied what effect alcohol and tobacco could have on pregnancy, researchers have begun to place cannabis under a similar microscope. A recent study, however, focused on the male side of things. According to a report published in Epigenetics, habitual cannabis usage could reduce male sperm count and also alter sperm as well. Previous studies have also shown that cannabis use could lower sperm count.
Scientists at Duke University discovered that cannabis use could significantly change how genes operate in the cells. In other studies, similar changes in sperm’s genetic makeup were associated with abnormal growth and cancer. However, researchers could not determine if these changes affected fertilization and the long-term health of children. They did advise caution, though.
In the absence of a larger, definitive study, the best advice would be to assume these changes are going to be there [in sperm],” said study co-author Susan Murphy, a gynecology professor at Duke. “I would say, as a precaution, stop using cannabis for at least six months before trying to conceive.”
The study was divided into two different types of participants: rats and humans. One group of rats was given THC, the psychoactive component of cannabis, and another group was not. Duke scientists also recruited 24 human males, comparing the sperm of men who consumed cannabis weekly and men who smoked marijuana less than 10 times in their lives.
In both humans and rats, scientists found lower sperm counts and altered genes in the sperm. Though researchers did not control for THC count in male cannabis users, they did find that more THC in the urine correlated with more changes in the sperm.
Murphy emphasized this was a pilot study originally focused on if cannabis usage had an effect on sperm whatsoever. The scientists have already planned follow-up studies.
“We don’t yet know what that means, but the fact that more and more young males of child-bearing age have legal access to cannabis is something we should be thinking about,” senior study author Scott Kollins, a psychiatry professor at Duke, said in a statement.
Numerous scientists have stated the need for further research on just what effect cannabis could have on sperm. Would they have long-term impact on offspring and how mutable sperm could be to change cannabis usage represent just some of the questions scientists hope to explore.
“I want to be very careful to not have the results turned into something that they’re not,” Murphy told The Verge. “It’s not intended to scare people. Our whole objective is to learn more about biology and what effects there might be.”