A study by Harvard University found that men who once smoked marijuana had a semen concentration of sperm 28% higher than those who had never used marijuana.
A sample of marijuana.
American doctors found a link between smoking marijuana and sperm quality indicators. According to the article published in Human Reproduction, average smokers have a higher concentration of sperm and blood testosterone levels than those who never used the drug.
This study based on the nervous system effects explains that the active principle of marijuana (delta-9 tetrahydrocannabinol) is capable of selectively binding to the cannabinoid receptors in the brain. But humans produce endocannabinoids, a substance that is structurally similar to cannabinoids in plants. This component integrates the endocannabinoid system and is associated with the regulation of certain physiological processes, particularly fertility and pregnancy. In the case of animals, the studies also showed that the endocannabinoid system participates in the regulation of spermatogenesis.
While scientists previously investigated the effects of the plant on the reproductive system of men, they were involved people who had abused the drug for a long time. Regarding healthy men who moved regularly, the studies concluded in a lower number of semen in the semen and in an increase in the concentration of testosterone in the blood. Therefore, a correlation was observed between the increase in the dose of the drug and the decrease in the number of sperm.
Virility under the magnifying glass
To better understand how marijuana smokes affect the male reproductive system, doctors at Harvard Institute of Public Health and Harvard Medical School led by Jorge Chavarro conducted a thorough investigation of nearly two decades (2000-2017).
662 men (with an average age of 36.3 years) attended the Infertility Treatment Center at Massachusetts General Hospital. A total of 1143 semen samples and 317 blood samples were collected. In addition, the participants completed a questionnaire with questions about age, education, ethnicity, habits and frequencies such as marijuana smokers. They were even asked if they would smoke right there.
55% of respondents (365 people) today smoke marijuana; 44% earlier and 11% did so during the investigation. On average, 2 marijuana cigarettes per Week. 88% of the participants were white, 84% had a higher education and 94% did not move tobacco during the investigation period.
With regard to the samples, the researchers analyzed the quality of the sperm, confirmed the concentration and the number of sperm; they observed their mobility and DNA integrity and the concentration of sex hormones in their blood. Until then, specialists suggested that marijuana users would have a lower quality of sperm than those who had never used it.
Unexpectedly, men who once had smoked marijuana were a semen concentration of sperm 28% higher (62.7 million sperm per milliliter) than those who had never used it (45.4 million sperm per milliliter). On the other hand, the concentration of sperm in ex-smokers and in current smokers was about the same; and in the latter case, they had a sperm 24% higher than those they had never used: 150 million sperm versus 114 million. Also, in men who once used marijuana, the testosterone level in the blood was higher.
Feiby Nassan from the Harvard Public Health Institute explains how such an unforeseen event is possible: "Our results contradict the original hypothesis, but they are consistent with two different interpretations: the first is that low doses of marijuana can affect the endocannabinoid system, regulating fertility, which in turn can contribute to the development of semen, but this benefit disappears with a higher level of drug consumption, an equally credible explanation being that men with higher levels of testosterone tend to behave more risky than smoking marijuana. "
The researchers indicate that these results should be treated with complete caution. Perhaps some participants who actually use marijuana refused it in the negotiations. To understand whether the amount of marijuana affects spermatogenesis and testosterone levels, a deeper study will be needed.
Meanwhile, marijuana goes fast and not so slowly against its legalization. One of the notable arguments is that it is relatively harmless and beneficial to certain health disorders. The United States last year approved the use of the drug for the treatment of convulsive syndrome in two rare forms of epilepsy. And the legalization of marijuana in 25 states for medical purposes reduced the use of opioid drugs.