Consuming cannabis affects the epigenetics of the smoker, thus altering his genetic profile and that of the spermatozoa in men. Results that raise questions about the possible consequences for the future children of consumers.
Previous studies have already shown that smoking tobacco acts on the functionality of spermatozoa, in particular by degrading the DNA transmitted to the embryo. In a new study, American researchers have shown that smoking cannabis can also cause a change in the genetic profile of sperm. Their results were published in the journal Epigenetics.
THC alters the genetic profile of sperm
Tetrahydrocannabinol, or THC, the active principle of cannabis, impacts the epigenetics of smokers but could also potentially modify the genetic profile of their future offspring. “What we found is that the effects of cannabis use on men and their reproductive health are not completely zero, in that cannabis use affects the genetic profile of sperm” , said Scott Kollins, professor of psychiatry and behavioral sciences and lead author of the study.
The researchers conducted experiments on rats, then on 24 men. They compared the sperm of regular smokers, defined here as those who smoked marijuana at least once a week in the six months prior to the study, to those who had not used marijuana during that time and no longer. ten times in their lifetime.
An influence on the offspring to be specified
They found that THC impacts hundreds of different genes, but it targets genes in two main cellular pathways and alters DNA methylation, a process essential for normal development. One pathway involves helping organs in the body grow to their maximum size, while the other involves a large number of genes that regulate growth during development. “We don’t yet know what this means but we should think about the fact that more and more young men of childbearing age have legal access to cannabis,” said researcher Scott Kollins.
Regarding the impact this may have on the future children of cannabis smokers, researchers remain cautious. “As far as the impact this has on the developing child, we just don’t know,” said Susan Murphy, a researcher who was involved in the study. “It is not even known whether THC-affected sperm could be healthy enough to even fertilize an egg and continue development into an embryo,” she said.
Stop cannabis 6 months before conceiving
The study is a starting point for research into the epigenetic effects of THC on sperm. The too small number of men involved in the trial makes it impossible to generalize and the results could also be confused with other factors affecting their health, such as their nutrition, sleep, alcohol consumption and other lifestyle habits. However, it is a starting point, with researchers saying they want to continue research on a larger group. They also say they want to study whether sperm changes are reversed when men stop using marijuana. They hope, finally, to test the umbilical cord blood of babies born to fathers with THC-modified sperm to determine what epigenetic changes, if any, are passed on to the child.
“We know that cannabis use has effects on sperm DNA regulatory mechanisms, but we don’t know if they can be passed on to the next generation,” Susan Murphy said. “In the absence of a larger definitive study, the best advice would be to assume that these changes will occur. We don’t know if they will be permanent. I would say as a precaution stop using cannabis for at least six months before trying to conceive.”
