3rd December 2021
By Roland Sebestyén

A recent study of cannabis in mice has found that exposure to cannabis vapour may not only affect sperm counts and motility in the directly exposed individual but also in their offspring.

Researchers from Washington State University used a mouse model of cannabis exposure to assess potential risks to fertility. The results revealed that cannabis use can, in fact, have an impact on sperm count, as well as the movement and speed of the cells.

Kanako Hayashi, the study’s corresponding author, and an associate professor at WSU said the findings should give “cannabis users a pause.”

She said: “This is a warning flag. You may take cannabis for some kind of momentary stress, but it could affect your offspring.”

For the study, researchers compared 30 adult male mice, exposing 15 of them to cannabis vapour three times a day for ten days straight. The researchers noted that while this may seem like an intense amount, the main goal was to mimic the cannabis intake of frequent cannabis users.

The researchers then compared the sperm counts and motility of the cannabis exposed mice with the unexposed control group, and the results were alarming: they found that, immediately after the exposure period, the mice’s sperm motility decreased, and after one month, sperm counts were lower.

The researchers also bred several of the male mice with unexposed female mice.

Shockingly, the male offspring of the cannabis-exposed mice also showed evidence of DNA damage and disruption related to sperm cell development.

Ms Kanako added: “We were not expecting that the sperm would be completely gone or that motility would be completely offset, but the reduction in sperm count and motility of the offspring, the sons, is probably a direct effect of the cannabis exposure to father.”

It is reported that the grandsons of the affected mice, however, did not show the same impacts, indicating that exposure “impacted the second-generation mice at a developmental stage.”

While these findings are alarming, it remains unclear whether the same effects are detectable in humans. More studies are needed to determine the real potential harms of frequent cannabis exposure.

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