CBD, the widely available cannabinoid touted for various health benefits, may have the potential to help people with serious alcohol issues, according to a new review of current scientific evidence.
Not only does cannabidiol appear to “facilitate drinking reduction,” the paper’s authors write, but research also shows the compound “may provide idiosyncratic protection to the liver and brain, which could reduce the development and impact of alcohol-related liver disease and alcohol-related brain injury.”
The review, which is awaiting publication in the journal Frontiers in Pharmacology, offers a comprehensive look at how promising the data is so far regarding the effectiveness of CBD on alcohol use disorders (AUD). The authors, however, also call for human clinical trials, of which none have been published to date, to “pave the way for testing new harm reduction approaches in AUD.”
Researchers in France and Belgium reviewed 26 previous studies published between 1974 and June 2018 that explored the effects of CBD on animal subjects dosed with ethanol. They found several studies that showed CBD can reduce alcohol consumption. In one, for example, researchers discovered that mice administered CBD were less motivated to work (in this case, push a lever) for access to a liquid solution that included 8 percent of ethanol.
“Experimental studies converge to find that CBD reduces the overall level of alcohol drinking in animal models of AUD by reducing ethanol intake, motivation for ethanol, relapse, and by decreasing anxiety and impulsivity.”
Other studies found that mice regularly dosed with the non-intoxicating marijuana compound were also less likely to relapse after they’d been weaned off alcohol, even when they were stressed.
Because of its impact on various aspects of the disease (including “intake, motivation, relapse, anxiety and impulsivity”), CBD “could have a significant action on drinking levels in human subjects with AUD” the review’s authors write. They add, however, that it would be useful to have data using binge-drinking models and models that focus on long-term exposure to alcohol.
The review also highlighted evidence showing CBD could affect alcohol-related liver inflammation. In one study, researchers found that the livers of mice that’d been given the compound prior to being force-fed alcohol every 12 hours for five days were less damaged than those of mice not exposed to CBD.
“CBD seems to have valuable therapeutic properties for ethanol-induced liver damage, through multiple mechanisms,” including the reduction of oxidative stress, inflammation control, and the death of certain cells responsible for large amounts of scar tissue, the authors write.
Finally, CBD may also offer added protection to specific areas in the brain susceptible to alcohol-related damage. In one study, the brains of rats who’d binged on alcohol and given CBD were found to have lost “significantly” fewer brain cells in the hippocampus and entorhinal cortex. In those rats, CBD acted as a “neuroprotective antioxidant,” the review states. In another experiment, CBD also appeared to restore the neurological and cognitive functions of rats in acute liver failure.
“CBD has been found to reduce alcohol-related brain damage, preventing neuronal loss by its antioxidant and immunomodulatory properties.”
The authors suggest these overall benefits of CBD regarding problematic alcohol use may be due to the “complex” way the cannabinoid interacts with CB2 receptors, which are located throughout the body.
Currently, the review states, the pharmaceuticals available to help people with AUD stop drinking are “insufficiently effective at a population level, and new therapeutic prospects are needed. Moreover, no drug for reducing alcohol-related harms, either on the brain or the liver, has ever been studied.”
Plus, the authors conclude, “CBD could have many more positive effects in subjects with AUD, including antiepileptic, cardioprotective, anxiolytic, or analgesic ones. Human studies are thus crucially needed to explore the many prospects of CBD in AUD and related conditions.”
Meanwhile, there’s still time to submit public comments to the U.S. Food and Drug Administration on how the federal government should regulate CBD products, including supplements and foods. So far, hundreds of people have submitted information. The public comment period ends July 2.
Photo by Kimzy Nanney.
THC-Infused Semen Can Be A Side Effect Of Frequent Marijuana Use, Study Finds
Many people have had to take a urine test for cannabis, perhaps as a job requirement. Using the popular procedure, marijuana metabolites can in some cases be detected for weeks after a person’s last use. But here’s a question few may have thought to ask: Can THC be detected in semen?
According to a new study by a team of Harvard Medical School researchers, the answer is yes—at least sometimes. In a study of 12 participants who regularly consumed marijuana by inhalation, the researchers were able to detect delta-9 THC, the main psychoactive ingredient in cannabis, in two subjects’ semen samples. And at least one metabolite of THC—what’s left over after the body processes the compound—could be detected in all samples capable of being analyzed. “Two semen samples,” the report says, “had insufficient volume to be analyzed.”
Why the focus on THC in semen? In a word, pregnancy. Men of reproductive age, the study’s authors note, “are the most prevalent consumers of marijuana, with 19.4% of men in the USA reporting use.” A 2018 study cited by the authors found that 16.5 percent of men and 11.5 percent of women reported using marijuana while attempting to conceive.
How exactly THC affects reproductive systems and childhood development are questions the Harvard authors don’t attempt to answer in the study. The primary goal of the proof-of-concept research, they explain, “was to determine whether THC can cross the blood-testis barrier.” On that front, they appear to have succeeded.
“In the setting of a growing repository of data surrounding the effects of the endocannabinoid system in the regulation and maintenance of fertility and early pregnancy,” the study says, “ours is the first report that the exogenous cannabinoid THC can be detected in any human reproductive matrix.”
Because of the interest in whether THC could be detected at all, researchers focused on regular, long-term marijuana consumers. All participants indicated they had used the drug between 25 and 30 days of the last month, and most said they had been regular consumers for at least five years. “Consequently,” the team said, “our study findings cannot be generalized to include ever users, light, or moderate users of marijuana.”
Of the two participants whose semen contained detectable levels of THC itself, samples contained 0.97 nanograms per milliliter and 0.87 ng/mL.
But it wasn’t clear what set those two participants apart. There was no correlation between semen THC and concentration of the metabolite THC carboxylic acid in urine, nor with time since last cannabis consumption, participant age or participant body mass index.
“It is puzzling that some, but not all, semen samples tested positive for THC,” the study says. “There were no obvious factors that were strongly associated with detectable semen THC; thus, we can propose few predictors of the presence of THC in human semen. Future directions (of research) include identifying characteristics that may affect semen detectable THC levels.”
How precisely THC affects semen—or the sperm within it, not to mention conception, pregnancy or childhood development—is still hard to say with certainty. As the Harvard researchers note in the study, “Evidence linking marijuana to reproductive outcomes is scarce and to date, often conflicting.”
One study of 1,200 young Danish men, for example, found that those who smoked marijuana regularly had lower sperm counts than those who did not. Another study, of 662 older, subfertile men in Massachusetts, found that men who had ever smoked marijuana had significantly higher sperm counts than those who’d abstained.
As for the effects of THC on sperm, or conception itself, those also remain unclear. “The effect of marijuana on human gametes and fertilization is relatively unknown,” the new paper says. Endocannabinoid receptors have been reported on sperm themselves, but “studies examining the direct effect of THC on human sperm are limited.”
Most research so far has either been observational, by measuring THC through self-reporting or blood testing, or studied the behavior of sperm that had been washed in a laboratory with a THC solution. “Our findings, that THC can be directly quantified in human seminal fluid, lay the groundwork to allow for future studies,” the new study says. “Since THC can be detected in the seminal fluid of some individuals, this might provide a direct method of measurement (rather than relying on self-reporting marijuana use, which is subjective and potentially unreliable, or serum levels which only reflect recent exposure) to bridge real-world clinical studies with the prior staged studies in which THC was directly incubated with washed sperm.”
While the THC-washed sperm showed some concerning effects, including decreased motility and mitochondrial oxygen consumption, the Harvard team acknowledged the concentrations of THC used in those studies were significantly stronger than anything observed in their semen study: “It should be noted that even the lowest concentration of THC with which former studies incubated sperm was over tenfold higher than the concentration of THC detected in the semen of our study subjects.”
In other words, the study is a stepping-stone to further research. And while the top-line findings might elicit some giggles, authors say the study is serious business.
“The ability to quantify cannabinoids in human reproductive tissues and fluids,” they conclude, “gives us the capability to directly study the effects of cannabis on early human reproduction.”
States With Medical Marijuana Laws Saw 20% Drop In Some Opioid Prescriptions
States with active medical marijuana laws saw certain opioid prescription rates drop nearly 20 percent compared to prohibition states, a first-of-its-kind study out of Columbia University’s Irving Medical Center has found. Authors said the findings underscore the importance of providing patients with pain management alternatives, such as cannabis, in efforts to reduce opioid use.
Drug overdoses remain a leading cause of injury-related death in the United States, and the U.S. Centers for Disease Control and Prevention reports that 68 percent of those deaths involve illicit or prescription opioids. The new study examines opioid prescriptions made specifically by orthopedic surgeons, who it notes are the nation’s third-highest prescribers of opioids.
“Although our study does not support a direct causal relationship, these population-level findings show that legalization of medical cannabis and patient access to dispensaries may be associated with reductions in opioid prescribing by orthopaedic surgeons,” the study’s authors concluded. “The observed trends reported in this study may be a reflection of growing availability of alternative pain management options for patients.”
“We found that overall opioid prescribing by orthopaedic surgeons in this cohort was reduced in states permitting patient access to medical cannabis, compared with those who do not.”
Analyzing nationwide Medicare Part D prescription drug data, researchers measured the aggregate daily doses of opioid medications prescribed by orthopedic surgeons in each state annually. They then looked for associations between that state-level data and the legal status of medical marijuana in each state.
As with past studies examining correlations between medical marijuana and opioid prescriptions, the Columbia analysis found a marked drop in prescriptions among states with medical cannabis laws (MCLs). “State MCLs were associated with a statistically significant reduction in aggregate opioid prescribing of 144,000 daily doses (19.7% reduction) annually,” the study, published this month in the Journal of the American Academy of Orthopaedic Surgeons, says.
Medical cannabis laws “were associated with a statistically significant reduction of 72,000 daily doses of hydrocodone annually.”
Not all state legal marijuana programs operate the same way, of course. It can also take years after a state adopts a medical cannabis law before its program is up and running. So the researchers looked at various specific factors, including when storefront dispensaries opened, whether state laws allowed home cultivation by patients, and whether recreational cannabis was legal for adults in each state.
Of the relationships that the researchers found were statistically significant, two stood out most clearly: States with active medical cannabis laws saw a 19.7 percent reductions in Medicare Part D opioid prescriptions made by orthopedic surgeons compared to states without medical cannabis laws. On a more granular level, states with operating storefront dispensaries saw a 13.1 percent reduction in those prescriptions.
Other relationships found by the researchers were just as likely to be due to chance. States with restrictive medical cannabis laws that allowed access only to low-THC products, for example, saw small, statistically insignificant increases in opioid prescriptions.
Researchers also “did not observe any significant association between total opioid prescriptions and home cultivation–only” medical cannabis laws, and concluded that “no significant association between recreational marijuana legalization and opioid prescribing was found.”
In “states that allow physicians to recommend medical cannabis to patients for any reason, there was a significant reduction in prescriptions for fentanyl…”
Cannabis is a particularly appealing alternative pain medication to study the effect of, the authors wrote, “because of its efficacy in treatment of chronic and acute pain and its potential for replacing and/or reducing opioid treatment.”
Researchers adjusted some of their data to better reflect not just the laws on the books but the actual accessibility of medical marijuana in each state. New York, for example, adopted a medical cannabis law in 2014, but home cultivation was prohibited and dispensaries didn’t open until 2016. “As such,” the authors wrote, “we did not classify New York as an MCL state or a dispensary-based MCL state until 2016.”
The study also cautions that its results only mean so much. Because it relied on population-level data and didn’t track individuals’ opioid or medical marijuana use, “we could not make any conclusions about any direct effect of substitution of opioids for cannabis by patients on prescription trends.” the authors wrote. “As such, our study does not draw conclusions of direct causation, but reports observed associations over time using a nationwide cohort database and multivariable regression analysis.”
Still, the study’s results contribute to a growing body of research indicating that medical cannabis accessibility significantly reduces statewide opioid use—and even opioid deaths. As the Columbia authors note in their report, “Multiple large nationwide database studies have shown that states with the legalization of medical marijuana have seen reductions in the opioid prescription rates and opioid-related mortality rates. The authors of these studies have theorized that in states where medical cannabis is more available, patients are likely to substitute cannabis for opioids in their pain management.”
For example, a meta-study that was recently published also signaled that marijuana shows promise as a treatment option for chronic pain and could serve as an alternative to opioid-based painkillers.
Last month, researchers released a study that found cannabis can mitigate symptoms of opioid withdrawal.
In December, researchers determined that states with legal marijuana access experience decreases in opioid prescriptions, and a separate study released the previous month showed that daily marijuana consumption is associated with reduced opioid consumption among chronic pain patients.
Legalizing Marijuana Boosts Hotel Bookings As Cannabis Tourism Takes Off, Study Shows
Colorado hotel room rentals increased considerably after the state began legal marijuana sales, a newly published study reveals. Washington State also saw increases in tourism after legalization, though the effect there was more modest.
The two states were the first in the U.S. to allow adult-use cannabis through laws approved by voters in 2012. By comparing hotel room rentals in Colorado and Washington to states that did not change their legal status of marijuana from 2011 through 2015, researchers found that legalization coincided with a significant influx of tourists and a rise in hotel revenue. The impact was even more pronounced after the start of retail sales.
In both states, personal possession of marijuana was permitted for a period of time before legal sales began, and each change coincided with increases in tourism. In Colorado, legalizing possession led to monthly hotel booking increases of 2.5 percent to 4 percent, depending on the modeling method used. Once retail stores opened, the state saw bookings increase by 6 percent to 7.2 percent.
“[L]egalization in Colorado is associated with an increase of nearly 51,000 hotel rooms rented per month [and] once commercial sale is permitted, there is an increase of almost 120,000 room rentals per month”
In Washington, the increases were roughly half that. Hotel bookings increased by about 1 percent after legalizing possession and 3.5 percent after retail stores opened.
The price of a hotel room in both pioneering legal cannabis states also rose during that time, relative to other states that maintained prohibition. Room rates in Colorado increased by about $3.76 (2.8 percent) after possession became legal and $6.31 (3.8 percent) once legal sales began.
“As expected, legalizing marijuana sales is associated with a larger increase in hotel room rentals than merely legalizing marijuana possession.”
Meanwhile, Colorado’s hotel industry saw monthly revenue increase by $9.33 million (6.75 percent) after the change in possession law and roughly $23.71 million (11 percent) after marijuana stores opened.
“Marijuana tourism had an economically significant as well as a statistically significant effect on the hotel industry in Colorado,” the study concluded.
Washington saw a smaller increase in room rates after possession became legal ($1.10) but a larger one ($7.46) once legal sales began.
Researchers believe that the difference the states saw may be the result of Colorado’s more central location for American tourists—”Denver’s airport is a major hub for United Airlines,” the paper notes. Another factor could be Washington’s proximity to British Columbia, which researchers point out “has a strong reputation for growing marijuana and a laid back attitude toward marijuana consumption.” (Recreational marijuana was illegal in Canada during the duration of the study period. The country has since legalized nationally, and adult-use legal sales began there in 2018.)
“Another possible explanation is that Colorado may have achieved a first mover advantage over Washington since it legalized commercial sale six months earlier than Washington,” the study speculates.
The study, “(Pot)Heads in Beds: The Effect of Marijuana Legalization on Hotel Occupancy in Colorado and Washington,” was published online last week and appears in the latest issue of the Journal of Regional Policy and Analysis.
“It is easy to see the implications marijuana legalization might have for tourism,” the paper says, noting that “Amsterdam’s permissive legal tolerance of drugs (and other activities) attracts visitors from around the world, sometimes to the weariness of the Dutch public.”
But until now, evidence of rising tourism in U.S. states was mostly anecdotal. Authors of the new paper wanted to measure the effect through data—and on that front, existing research was thin. A 2015 report commissioned by the Colorado Department of Revenue estimated that tourists made up a large portion of the state’s retail marijuana activity, accounting for 44 percent of metro-area sales and about 90 percent of sales in tourism-centric mountain counties.
“These results suggest an uptick in tourism following marijuana legalization,” the new study says, but until now “there have been no studies directly examining the effect of legalization on tourism.”
The study’s authors are confident in their conclusion that legalization boosted tourism in Colorado and Washington during the first few years of legal marijuana. What’s less clear is how long that boost might last.
“While marijuana legalization increased tourism, especially in Colorado,” they write, “the benefit may wane as additional states including California, Michigan, and Illinois, legalize the possession and sale of marijuana.”
The governor of Illinois, which began legal cannabis sales in January, said in his State of the State address this year that the new law “gives us a chance to collect tax revenue from the residents of Wisconsin, Missouri, Iowa and Indiana.”