Exposure to cannabis vapor causes lower sperm count in male mice and their offspring, study finds
- The study used 30 male mice – 15 were exposed to cannabis vapor three times a day for 10 days and 15 were not exposed at all
- Scientists compared sperm counts among the animals and found those exposed had a lower count, along with sperm that moved slower
- The mice exposed to cannabis were bred with female mice that were not
- The male offspring also had lower sperm counts and evidence of DNA damage
Using cannabis vapor is found to lower sperm count and the speed in which they move male users and their sons, a new study finds.
Researchers at Washington State University conducted the study with mice: Some were exposed to cannabis vapor three times a day for 10 consecutive days, while the rest were not, and then sperm counts between the two groups were compared.
The team found that immediately after the exposure period, the mice’s sperm motility decreased, and after one month, sperm counts were lower.
Male offspring of the mice exposed to cannabis vapor were also found with a lowered sperm count and motility, along signs of with DNA damage – even though the sons did not inhale the drug.
Scroll down for video
Researchers have revealed that cannabis has a relaxing effect on sperm leaving it ‘mellow’ and potentially cutting counts of the cells by a third
Kanako Hayashi, who is an associate professor in WSU’s School of Molecular Biosciences and the paper’s corresponding author, said in a statement: ‘This is a warning flag. You may take cannabis for some kind of momentary stress, but it could affect your offspring.’
A total of 30 mice were used in this study – 15 were exposed to cannabis vape and 15 were not.
After determining how the mice’s sperm was impacted the team then bred several of those exposed to cannabis vapor with unexposed females.
Not only did the male offspring show the same lower sperm counts and motility, but there was also evidence of DNA damage and disruption related to sperm cell development.
The team found that immediately after the exposure period, the mice’s sperm motility decreased, and after one month, sperm counts were lower. Male offspring of the mice exposed to cannabis vapor were also found with a lowered sperm count and motility
‘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,’ said Kanako.
A third-generation, the grandsons of the exposed male mice, did not show the same impacts, however, which suggests that the cannabis exposure impacted the second-generation mice at a developmental stage.
Not only does cannabis use slow down sperm, but a study in 2017 found it makes them ‘swim in circles.’
Another study from the University of South Australia found that there are differences between the way marijuana users and non-users walk.
Those who smoke the drug tend to have stiffer shoulders, more flexible elbows and quicker knees – which move faster than those of non-users.
While differences in movements were detected, there were no significant differences between the balancing abilities and neurological functions.
Along with impacting fertility, smoke cannabis can also increase the likelihood of suicidal thoughts.
Researchers from the US National Institute on Drug Abuse (NIDA) studied data on the mental health and drug habits of more than 281,000 young adults.
They found that only 3 percent of people who did not smoke cannabis had suicidal thoughts, but this rose to 14 percent for those with a ‘cannabis use disorder’ — a near five-fold increase.
However, these stats were observed for people without depression, and the figures for those with depression were even more alarming.
Exactly half of the adults with both depression and a cannabis use disorder — defined as problematic cannabis use — were revealed to have suicidal thoughts.
WHAT EVIDENCE IS THERE THAT CANNABIS INCREASES RISK OF MENTAL HEALTH ILLNESS?
- Schizophrenia: Researchers questioned more than 6,500 teenagers aged 15 and 16 on their cannabis use. They were monitored until the age of 30. Smoking cannabis just five times as a teenager can triple the risk of psychotic symptoms alongside major depression and schizophrenia in later life, according to the study at The Academy of Finland, published in the British Journal of Psychiatry in March 2018.
- Socially unacceptable behaviour: Researchers from the University of Montreal analysed around 4,000 13-year-olds from 31 high schools in the surrounding area for four years. Going from being an occasional marijuana user to indulging every day increases the risk of psychosis by up to 159 percent. Frequently abusing the substance also significantly reduces a user’s ability to resist socially unacceptable behavior when provoked. The research was published in the Journal of Child Psychology and Psychiatry in July 2017.
- Negative emotions: Scientists at the National Institute on Alcoholism and Alcohol Abuse in Bethesda analysed 60 people, half of which were cannabis dependent. The study’s participants completed a questionnaire that asked them about their feelings of stress, aggression, reactivity and alienation. Cannabis users are more likely to experience negative emotions, particularly feeling alienated from others. People who use marijuana are significantly more likely to feel that others wish them harm or are deceiving them. The research was published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging in January 2018.
- Panic attack reaction: Researchers from the University of Vermont scanned the brains of teenagers in Europe and found just one or two joints is enough to change the structure of a teenager’s brain. It could cause changes affecting how likely they are to suffer from anxiety or panic. Researchers found 14-year-old girls and boys exposed to THC had a greater volume of grey matter in their brains. This means the tissue in certain areas is thicker – the opposite of what usually happens during puberty, when teenagers’ brain matter gets thinner and more refined. The study was published in The Journal of Neuroscience in January 2019.
- Bipolar: Researchers at Warwick Medical School analysed 3,370 women’s cannabis use at 17 years old. At 22-to-23 years old, the participants completed a questionnaire. People who used cannabis at least two-to-three times a week at 17 years old are more likely to experience hypomania in their earlier 20s. Hypomania is defined as elevated mood alongside irritability or an inflated ego, an unrealistic sense of superiority, a reduced need for sleep and frenzied speech. Such symptoms frequently occur in bipolar disorder sufferers. The research was published in Schizophrenia Bulletin in December 2017.