Marijuana intake in men planning fatherhood could impact their sperm as well as the children they conceive, finds a study.
The effect is due to its active ingredient — tetrahydrocannabinol (THC), which like tobacco smoke, pesticides, flame retardants and even obesity can alter sperm.
The findings, from Duke University researchers, showed that THC also affects epigenetics, triggering structural and regulatory changes in the DNA of users’ sperm.
“What we have found is that the effects of cannabis use on males and their reproductive health are not completely null, in that there’s something about cannabis use that affects the genetic profile in sperm,” said Scott Kollins, Professor at Duke.
“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,” Kollins added, in the paper published in the journal Epigenetics.
THC appeared to impact hundreds of different genes in rats and humans, but many of the genes did have something in common – they were associated with two of the same major cellular pathways, said lead author Susan K. Murphy, Associate Professor at the varsity.
One of the pathways is involved in helping bodily organs reach their full size; the other involves a large number of genes that regulate growth during development. Both pathways can become dysregulated in some cancers.
“In terms of what it means for the developing child, we just don’t know,” Murphy said.
“It’s unknown whether sperm affected by THC could be healthy enough to even fertilise an egg and continue its development into an embryo,” she said.
The findings defined regular users as those who smoked marijuana at least weekly for the previous six months. Their sperm were compared to those who had not used marijuana in the past six months and not more than 10 times in their lifetimes.
The higher the concentration of THC in the men’s urine, the more pronounced the genetic changes to their sperm were, the team found.