– EN Fitness & Wellbeing – While research into smoking marijuana and fertility has been limited, it was widely believed that smoking too much pot could have a negative impact on a man’s sperm count.
But a new study has blown that notion out of the water, with scientists from Harvard University finding that men who smoke cannabis, or who lit up in the past, had higher sperm concentrations and counts.
“We spent a good two months redoing everything, making sure that there wasn’t any error in the data. We were very, very surprised about this,” researcher Dr. Jorge Chavarro from the Harvard T.H. Chan School of Public Health, said, explaining the team had expected to find the opposite.
To get their results, Dr. Chavarro and his colleagues analysed semen samples from more than 650 men, who had sought treatment at a U.S. fertility centre with their partners.
The test group were mostly white and college-educated, with an average age of 36, and were all asked about lifestyle factors, including drug use both past and present.
It was found that men who had used marijuana had a higher sperm count than those who never had, and that men who no longer smoked it had an even higher count than those who still did.
Dr. Chavarro was quick to point out that the results do not mean men should start smoking in a bid to increase their fertility chances, but rather the findings likely show men with higher testosterone levels are more likely to smoke the drug.
“It is well-documented that within normal ranges, high testosterone levels are associated with greater engagement in risk-seeking behaviours, including drug use,” he noted. “Higher testosterone levels are also related to slightly higher semen quality and sperm counts.”
Researchers also looked at cocaine use and sperm, and found it was linked to a lower quality. Dr. Chavarro points out that this could be the reason previous papers have concluded marijuana had a negative effect on fertility as multiple drug use could be the culprit, and not the weed.
The study has been published in journal Human Reproduction.