Cannabis and children are not often mentioned in the same sentence, but for men, wanting one may mean giving up the other. A new study from the Universities of Sheffield and Manchester found that smoking cannabis can harm sperm and reduce fertility.
The research showed that men who had used cannabis in the past 3 months were more likely to have oddly sized and shaped sperm.
According to previous research, doctors believe that a normal healthy man should produce plenty of sperm and around 5% of that sperm should be a healthy shape and size. Men who had smoked cannabis recently were more likely to have less than 4% of their sperm at a healthy size and shape.
Lead author Dr Allan Pacey, Senior Lecturer in Andrology at the University of Sheffield, said: "Our knowledge of factors that influence sperm size and shape is very limited, yet faced with a diagnosis of poor sperm morphology, many men are concerned to try and identify any factors in their lifestyle that could be causing this. It is therefore reassuring to find that there are very few identifiable risks, although our data suggests that cannabis users might be advised to stop using the drug if they are planning to try and start a family."
Other factors that were found to affect healthy sperm percentage were seasonal changes. Men are more likely to produce fewer healthy sperm in the summer which is probably due to the heat. The other factor that effects sperm production is working with organic solvents. Glycol Ethers in particular were shown to lower men’s healthy sperm production. Pain strippers and lead were also implicated in poor sperm production.
The study also looked at other drugs like alcohol and nicotine from smoking but these did not seem to play a role in healthy sperm count. The researchers caution the public though as drug use could affect reproduction in other ways and may still hinder fertility.
Currently the researchers are unsure as to why cannabis affects sperm production. However, as smoking normal cigarettes did not appear to harm healthy sperm levels, it is more than likely a chemical specific to cannabis rather than the by-products of smoking.
To learn more about cannabis, check out the Life Works Cannabis Knowledge Centre.