MAR 05, 2019 01:11 PM PST

Surprising Study Finds that Pot May Increase Sperm Concentrations

WRITTEN BY: Amy Loriaux

In a surprising report published in the journal Human Reproduction scientists from Harvard revealed their results of smoking marijuana on sperm health. Apparently, it may be good for it! The authors, led by Dr. Feiby L Nassan, cautioned that this result is surprising because they are "not consistent with a deleterious effect of marijuana on testicular function". They also caution that men should not go running to their nearest dispensary based on their study. However, the study does highlight the lack of quality research out there on how marijuana affects the body.

Photo source: PixaBay.com

The researchers used samples from a population of men at a local fertility clinic to study the association between self-reported marijuana smoking and markers of testicular function. Markers for semen quality used in this study included sperm concentration, sperm DNA fragmentation, and serum reproductive hormones. In line with the previous literature on the subject, the authors themselves predicted a negative effect of marijuana smoking on testicular hormones. Boy were they surprised.

Their results showed a significantly higher sperm concentration in men with a prior history of smoking marijuana than those who did not (average sperm concentration of 63 million sperm per milliliter of semen, compared with 45 million sperm per milliliter of semen among those who had never used marijuana). Nevertheless, there were no associations of a history of marijuana with other measures, such as markers of sperm DNA integrity or other reproductive hormone concentrations.

Because these results were unexpected, the researchers re-categorizing marijuana smoking based on the last time of reported use and after restricting analyses to men without a diagnosis of male factor infertility. Further analyses looked only at the first semen sample per man and further adjusted for stress levels or history of STDs. Finally, the researchers adjusted for time of sample collection to testosterone analysis. Despite this deep analysis, the main findings remained the same.

Photo source: PixaBay.com

The authors pointed out the various flaws in previous studies, some of which are over 30 years old. These studies used men with a much wider history of multi-drug abuse, which may have confounded their results. The most recent comparative study, performed in 2015 in a population of Danish men, found that marijuana decreased sperm concentration. Yet, the authors of the present study raised the possibility that the amount of marijuana smoked could be a factor in determining the effects of marijuana. Thus, they proposed that marijuana could increase concentration in moderate users, but greater use could lead to low concentrations. This is a common pharmacological process known as the "inverted U-shaped curve" and is present in many physiological functions, such as stress

One final interesting piece in this puzzle is the data from animal studies which show a role for the endocannabinoid system in spermiogenesis. Apparently, genetic inactivation of the endocannabinoid receptor CB1 in mice causes DNA damage in sperm. Also, in genetic CB1 knock-out mice sperm lose the ability to function normally. The results of the current study are surprising compared to the human but not the animal literature. This means that their results should be interpreted very carefully. Ultimately, more experimental studies on animals and humans are needed to determine what to do with the results.

See the video below detailing the complex results of studies on smoking and overall sperm health.

Video source: YouTube.com

SourceHuman Reproduction, Fertility and Sterility, www.livescience.com, Advances in the Biosciences, American Journal of Epidemiology, www.mindtools.com, Proceedings of the National Academy of Science of the United States of America, Frontiers in Endocrinology, Endocrinology, General and Comparative Endocrinology

 

 

About the Author
  • I am passionate about science. My specialties include neuroscience and psychology. I have over 10 years of biomedical neuroscience research at Arizona State University and the University of Texas at Southwestern Medical Center.
You May Also Like
SEP 20, 2018
Cannabis Sciences
SEP 20, 2018
Hemp or Hype? Is Hemp the Real Deal?
Hemp is a form of the cannabis plant that was specially bred for its use in textiles. It contains very little of the psychoactive component, tetra-hydrocan...
OCT 17, 2018
Cannabis Sciences
OCT 17, 2018
What is the FDA Doing About Medical Marijuana?
You may be wondering, with all of these changes in marijuana laws occurring around the country, is anybody monitoring it? In terms of medical marijuan...
OCT 23, 2018
Cannabis Sciences
OCT 23, 2018
Does Marijuana Help or Hinder Stroke Recovery?
A recent study reported in the Journal of Stroke and Cerebrovascular Diseases has found that marijuana smokers have a higher rate of hospital adm...
DEC 13, 2018
Cannabis Sciences
DEC 13, 2018
Does Vaping Get You Higher Than Smoking?
A recent report from Johns Hopkins Behavioral Pharmacology Research Unit in Baltimore published in JAMA Network Open.  Using 17 healthy...
DEC 20, 2018
Cannabis Sciences
DEC 20, 2018
Marijuana and Racism: A History
Various drugs have various stereotypes. Cocaine is linked with highly-paid, white-collar workers while crack is linked to poor, disenfranchised people. Ecs...
JAN 02, 2019
Cannabis Sciences
JAN 02, 2019
Why Does Cannabis Help Arthritis?
One of the main health claims for marijuana is rheumatoid arthritis (RA). If marijuana acts to alleviate symptoms of rheumatoid arthritis, it begs the ques...
Loading Comments...