Cannabis Improves Sperm Quality in Rats, Study Finds
Cannabis leaf extracts can significantly improve sperm quality and increase levels of hormones important to male fertility, according to a new study led by researchers from Landmark University, Nigeria.
Published in BMC Complementary Medicine and Therapies, the study looked at the effects of three different concentrations of ethanolic leaf extract of cannabis (ELEC) on the fertility of male rats, compared to the antioxidant vitamin C and an inactive control.
The researchers found significant improvements in sperm count, sperm motility, and testicular weight, which may indicate that the flavonoids in ELEC have antioxidant properties strong enough to protect testicular and sperm cells from damage.
Further research into cannabis leaf extracts may one day lead to the discovery of new drugs for treating infertility, the researchers say.
Cannabis leaf extract improves sperm quality in rats
Oxidative stress is a major factor in male infertility as testicular tissues are particularly vulnerable to oxidative damage. Oxidative stress can also negatively impact the morphology of sperm cells and their DNA, leading to more problems. As a result, antioxidants are sometimes used as an alternative therapy for idiopathic male infertility problems.
The cannabis plant contains many phytochemicals with potential antioxidant properties, and so there is a need to evaluate whether the plant could be used as an alternative fertility treatment.
For this latest study, the researchers prepared ethanolic leaf extracts of cannabis (ELEC) at three different concentrations: 5 milligrams per kilogram (mg/kg), 10 mg/kg, or 20 mg/kg body weight. The phytochemical content of each ELEC was evaluated using high performance liquid chromatography ultraviolet (HPLC-UV) spectroscopy.
Groups of five male rats were given one of the ELECs, an oral solution of vitamin C, or an inert control orally for 60 days. After this time, sperm and testicular tissue samples were tested to assess for any changes in testicular function and sperm health.
The researchers found the ELECs to have significant amounts of antioxidant phytochemical compounds, including flavonoids, steroids, alkaloids, and phenolics. The researchers did not specifically report any amounts of CBD or THC being detected, though it should be noted that cannabinoid levels in cannabis leaf are generally much lower than in cannabis inflorescences.
After 60 days of treatment, they found that the animals given vitamin C or ELEC doses had significant increases in sperm volume, concentration count, motile count, total sperm count, and percentage motility. Sperm motility is one of the most important parameters used when assessing fertility, as it is a direct measure of the sperm’s ability to move to where it could fertilize the ova.
The vitamin C and ELEC groups had a higher number of fast-moving sperms and significantly more morphologically normal sperms than the control group. The rats in the ELEC group also tended to have a greater percentage weight gain in the testis, which the researchers say may demonstrate the lessoned cell death from oxidative stress in the treatment group.
Cannabis and fertility
In the ELEC-treated group, the researchers found there to be a significant increase in the concentrations of two sex hormones key to spermatogenesis: follicle-stimulating hormone (FSH) and luteinizing hormone (LH). They also found the ELEC group tended to display reduced serum testosterone levels. However, the researchers believe that the decreased testosterone may not have passed the threshold required to disrupt sperm production.
Interestingly, another recent study that looked at the effects of the cannabinoid tetrahydrocannabinol (THC) in monkey fertility also saw a noticeable drop in testosterone levels, accompanied by increases in FSH and LH levels.
In that study, after seven months of eating THC-containing edibles, the researchers found that the monkeys’ testicles had shrunk by around 57% on average, though no significant changes in sperm numbers, sperm morphology, or sperm motility were detected.
In contrast, another recent fertility study, this time using mice exposed to vaporized cannabis material, found that regular exposure to the cannabis vapor did result in lowered sperm count and sperm motility for the animals. This held true not only for the mice that were directly exposed to the cannabis vapor, but also for their sons.
“This is a warning flag. You may take cannabis for some kind of momentary stress, but it could affect your offspring,” study author Dr. Kanako Hayashi, associate professor in the Washington State University School of Molecular Biosciences, commented in a press statement.
Studies looking at the effects of cannabis on human fertility have returned similarly mixed results. A 2015 study of young Danish men found that those who used cannabis tended to have lower sperm concentration and a lower total sperm count than their non-using peers. In contrast, a study of American men visiting a fertility center in Massachusetts found that the cannabis users had higher sperm concentrations and sperm counts, and lower serum FSH concentrations, than men who had never smoked cannabis.
Given these mixed findings, more research into the effects of different cannabis preparations and their effects on testicular health and fertility are needed in order to fully characterize the relationship between cannabis and healthy male reproductive function.