Among the overwhelming variety of cannabis products available on the market today, the most effective for pain relief appears to be whole dried marijuana flower and products high in THC, a new study finds.
“Whole cannabis flower was associated with greater pain relief than were other types of products, and higher tetrahydrocannabinol (THC) levels were the strongest predictors of analgesia and side effects prevalence across the five pain categories,” researchers from the University of New Mexico wrote. “In contrast, cannabidiol (CBD) levels generally were not associated with pain relief except for a negative association between CBD and relief from gastrointestinal and non-specified pain.”
Using data from a mobile app that aims to educate users about cannabis products and help them track their experiences, the researchers found that most people who reported self-medicating with marijuana have short-term, yet significant, relief from pain. “In our sample,” they write, “we observed an average pain reduction of roughly 3 points on a standard 0 to 10 visual analogue pain scale, consistent with its application as a mid-level analgesic.”
The findings, published in Complementary Therapies in Medicine in late July, are the latest in a robust body of scientific literature that shows marijuana can help people with different kinds of pain.
The study’s goal was to gauge how the severity of pain changed and what side effects were experienced after cannabis consumption, and whether these effects differed by product. Researchers used information gleaned from Releaf App, a mobile software program developed by three of the study’s authors and released in 2016. The app allows users to monitor their symptoms before, during and after consuming cannabis, thus helping them to understand the differences between products and delivery methods.
The study—which calls the Releaf data set “the largest database of real-time cannabis administration sessions in the U.S”—analyzed 20,513 cannabis sessions recorded in the app by 2,987 people between June 6, 2016 and October 24, 2018.
“Perhaps the most surprising result,” lead author Xiaoxue Li said in a statement, “is just how widespread relief was with symptom relief reported in about 95 percent of cannabis administration sessions and across a wide variety of different types of pain.”
“The results suggest that cannabis flower with moderate to high levels of tetrahydrocannabinol is an effective mid-level analgesic.”
On average, users reported their starting pain to be 5.87 on a scale of 1 to 10. After consuming marijuana, that number fell to 2.77—a decrease of 3.1 points.
“Among the limited number of product characteristics that are typically made available to consumers, we found that consumption of whole, natural Cannabis flower was associated with greater anesthetic potential than were most other types of products,” the authors wrote.
The study also found:
- Patients whose cannabis sessions involved flower reported similar pain relief as those using concentrates and topicals. Edibles, pills and tinctures, however, offered less relief than flower.
- Concentrates were found to be associated with more negative side effects, which the researchers reasoned could be because of solvents and other additives, as well as the removal of most terpenoids, terpenes and flavonoids.
- Products labeled as hybrid strains were more effective at relieving pain than those labeled indica or sativa.
- Combustion method didn’t affect pain.
- Higher THC levels offered more pain relief, while higher CBD levels did not.
- Patients with back, joint or muscle pain, headache or migraine and non-specified pain saw more relief with high-THC products.
- Patients with gastrointestinal/abdominal-related pain found more relief with lower levels of THC.
As for other reactions, patients were more likely to report positive effects than negative effects: they cited dry mouth and feeling foggy as the most common negative ones, while feeling relaxed and peaceful were frequently reported as the most positive ones. Additionally, while CBD levels didn’t impact pain much, the cannabinoid did appear to decrease the likelihood of having negative side effects.
“The current findings,” the study concludes, “show that self-directed medical cannabis treatment, especially among users of higher THC products, is associated with significant improvements in at least short-term pain relief, perhaps a major reason why cannabis has become one of the most widely used medications in the United States.”
In a statement, Jacob Vigil, another study author and UNM associate professor of psychology, said the reason why dried cannabis flower may be more effective for pain is because of its “numerous constituents that possess analgesic properties beyond THC, including terpenes and flavonoids.” These compounds probably work together to increase cannabis’ therapeutic effects, he said.
“Our results confirm that cannabis use is a relatively safe and effective medication for alleviating pain, and that is the most important message to learn from our results,” Vigil continued. “It can only benefit the public for people to be able to responsibly weigh the true risks and benefits of their pain medication choices.”
Photo courtesy of WeedPornDaily.
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.”