Researchers in Canada have released the results of a new study on the development of molecular tools for cannabis breeders and researchers.

The goal of the research is to help develop tools to more easily identify specific genetic traits in cannabis sought by breeders, such as selecting traits for specific cannabinoid ratios for medical or non-medical applications. 

This study unveils high-value markers linked to essential agronomic and morphological traits identified through genome-wide association studies conducted on 176 drug-type cannabis samples.

Four key productivity-related traits were identified—fresh biomass, dried flower weight, sexual maturity and harvest maturity, as well as stem diameter, canopy diameter, height, internode length index, and node counts. Samples showed a significant variety in all of these traits, from low and high total biomass, height, flowering time, etc. 

One challenge in this type of work with cannabis, as explained in the research paper, is that the cannabis gene pool has been severely limited by prohibition and the specific demands of the commercial cannabis market. Despite this, cannabis still exhibits a notable level of phenotypic variation. 

This limited gene pool for cannabis is a problem for breeders as the plant lacks the robust wild-type or landrace gene pool available to many other commercially cultivated plants. Although hemp-type cannabis is somewhat distinct from “drug-type” cannabis varieties, they share enough common features that it can make identifying genetic variations difficult but a “critical necessity.”

Because of this, the findings, although requiring further analysis, can play a role in more efficiently and effectively identifying the desired genetic traits different breeders seek. This will require continued and growing collaboration between researchers and industry to utilize this new genetic knowledge and translate it into practical, innovative, and sustainable breeding strategies.

“Our findings open new avenues for advancing cannabis breeding programs and addressing the diverse needs of emerging industries,” concludes the paper. “The application of a high-density genotyping approach yielded an extensive catalogue of high-quality SNPs, effectively capturing the genomic diversity of drug-type cannabis. 

“The distribution of these markers across different chromosomes, coupled with high quality phenotypic data, facilitated the identification of molecular markers associated with complex agronomic and morphological traits. These markers hold great promise for further investigations to elucidate their functional links with phenotype variations, making them valuable assets for precision breeding efforts.”

Related Articles

Assessing the quantity and viability of cannabis pollen for breeding programs

January 28, 2022

Canadian cannabis producers say the process to vet new products needs an overhaul

May 8, 2023

How the THC obsession is killing classic cultivars

March 10, 2023

A new study is questioning the accuracy of a method used by police to determine cannabis impairment. 

Visual evidence of “eyelid tremors” is one of the processes used by Drug Recognition Experts (DRE) to supposedly confirm if a driver is impaired by cannabis use, including the RCMP.

“Eyelid tremor” is a term that refers to involuntary and intermittent spasms of the eyelid muscles and has often been associated with cannabis impairment. It’s identified under the Drug Evaluation and Classification Program of the International Association of Chiefs of Police. 

In Canada, cannabis impairment is often determined via visual inspection by Drug Recognition Experts trained in detecting impairment as part of a multi-step process that includes an examination of a person’s eyes. 

The objectives of this study were to assess the accuracy and replicability of identifying eyelid tremors as an indicator of recent cannabis smoking using a blinded, controlled study design.

About 100 people were recruited to participate in the study and divided into three categories: daily, occasional, and no current cannabis use. 

Participants then had their closed eyelids video recorded for 30 seconds by infrared videography goggles before and after smoking or vaping cannabis. 

Three observers with experience in movements of the eye and medical toxicology then reviewed these videos to determine which individuals had consumed or were impaired by cannabis based on a grading system. 

Researchers found that there was no significant association between recent cannabis use and the observers’ assessment that eyelid tremor was present. In fact, cannabis users were less likely to have eyelid tremors.

Because of this, the study says that the weak association between recent cannabis use and eyelid tremor does not support this method in identifying recent cannabis use.

The study concludes that additional research is needed to identify the presence of eyelid tremor more accurately. Furthermore, research should determine the relationship, if any, between cannabis dose and timeline in relation to last cannabis use to eyelid tremor and how, or if, it should be used for cannabis Drug Recognition Evaluator examinations.

A study from researchers in California in 2023 also concluded that, due to the high rate at which the officers determined people from the non-THC group as being impaired, field sobriety testing on its own may not be enough to accurately determine THC impairment.

Canadian experts have also questioned the reliability of field sobriety testing conducted by  Drug Recognition Experts (DREs). In Canada, police agencies like the RCMP conduct enforcement of drug-impaired driving using Standard Field Sobriety Testing (SFST) and DREs, in part due to the uncertainty as to the accuracy of THC-detection equipment. 

Canada had more than 27,000 people trained in SFST and more than 1,200 active DREs as of the end of 2021.

According to another comprehensive study in 2021, there is currently no straightforward way to equate measurements of THC levels in blood or saliva and current driving impairment. 

A 2021 report from Quebec based on coroners’ and medical examiners’ report data from toxicological analyses found that when cannabis was present, 20 percent had a THC blood concentration between 0.5 and 1.9 ng/mL, 44% between 2.0 and 4.9 ng/mL, and 36 percent over 5 ng/mL. Canada’s prohibited blood drug concentration (BDC) level is between 2 ng and 5 ng THC per ml of blood. 

A THC rate below 2 ng/ml does not necessarily indicate recent use, while a rate over 5 ng/ml is associated with impaired driving and recent use. In addition, a rate over 5 ng/ml increases the likelihood of an impairment-responsible crash. Polydrug use was found in 79% of cases.

Related Articles

Scientists are trying to teach our phones to know when we’re stoned

October 9, 2023

US study calls into question accuracy of field sobriety tests for cannabis

August 3, 2023

Drug impaired driving up in 2019, but not necessarily connected to legalization

July 17, 2021

A study published in the Journal of Neuroscience earlier this month found that cannabis users have greater emotional comprehension, a form of cognitive empathy.

While some medical professionals associate cannabis use with causing negative mental health and behavioural outcomes, this study found that cannabis users have a greater understanding of the emotions of others and that parts of the brain associated with empathy are stronger among those who use cannabis.

These findings, say the researchers, help to highlight positive effects of cannabis on interpersonal relationships and its potential therapeutic applications.

The study involved a group of 85 regular cannabis users alongside a control group of 51 non-users. The groups excluded those with neurological disorders, use of psychopharmaceuticals, depression, and MRI contraindications. 

Researchers “applied the Cognitive and Affective Empathy Test (TECA, in Spanish), developed by López-Pérez and Pinto, which analyzes the empathic ability of the subject, assessing both cognitive and affective empathy.” MRI scans were also used to assess brain activity in areas associated with empathy. 

The psychometric tests showed that cannabis users scored higher in emotional comprehension than non-users. They caution, however, that it’s possible the cannabis users they observed in the research were more empathetic prior to consuming cannabis.

The study also noted that the quality of cannabis consumed in Mexico is often around 2%–10% THC on the illegal market, much lower than cannabis consumed in legal markets in the US or Canada. Researchers caution this could lead to different results when using higher-potency cannabis.

The differences in THC concentrations between US and Mexican cannabis could have a differential impact on functional brain outcomes between the present study and those reporting emotional dysfunctions in cannabis users.  

The results of the MRI tests indicated that “regular cannabis users showed greater connectivity between the anterior cingulate cortex (ACC) and the pre-posterior central gyrus (pr-pCG). In the within empathy network analysis, the users showed greater connectivity between the left anterior insula (lAi) and the ACC, and greater network strength when compared to controls (t = 2.27, p = .02).”

The authors note that “the ACC is a region that is prone to the effects of cannabis consumption and is also greatly involved in empathy, which is a multi-component process that can be influenced in different ways. In the present study, regular cannabis users scored higher on emotional comprehension when compared to non-users.” 

“We believe that the differences shown by regular cannabis users in the emotional comprehension scores and their brain functional connectivity, could be related to the use of cannabis. However, we cannot discard that such differences were present before the users started their use of cannabis.”

They continue, saying that “this difference is consistent with those reported by Vigil et al., where cannabis users report a higher ability to detect others’ feelings compared to non-users. Additionally, previous research has shown that these types of psychometric results correspond with the subjective experience and behaviours of cannabis users related to a greater understanding of other emotions, less verbal hostility, enhanced prosociality and empathic predisposition to others’ situations.”

In closing, they hypothesize that they “believe that these results contribute to open a pathway to study further the clinical applications of the positive effect that cannabis or cannabis components could have in effect and social interactions.”

A study published recently in the American Chemical Society’s (ACS) journal Omega suggests that terpenes are only part of the picture when determining what compounds are responsible for the aroma of cannabis.

The study argues that different samples of cannabis that contain similar terpenes can smell wildly varied depending on the presence or absence of other nonterpenoid volatile compounds. The researchers also note that “cannabis labelling or certificates of analysis (COAs) that contain only terpene information thus may mislead consumers or producers into believing that these compounds are the sole source of a given product aroma.”

The researchers cite another recent study “that found that cannabis grown across the United States falls into three major classes [based on terpene constituents]: terpinolene/ß-myrcene, D-(+)-limonene/ß-caryophyllene, or ß-myrcene/pinene dominant varieties.” They proceed to note that, problematically, “this study showed varieties with very different aroma characteristics are often found in the same cluster, which is contrary to the paradigm that these dominant terpenes dictate their aromatic character.”

They go on to provide some examples of this. “For instance, Dogwalker OG, which possesses a skunky and woody aroma, was found in the same D-(+)-limonene/ß-caryophyllene cluster as Tropicana Cookies, which possesses an intense citrus and tropical aroma. Purple Punch, which possesses a sweet, grape-like scent, was also found in this cluster. This discrepancy suggests that while these classifications may be helpful for chemotaxonomic purposes, they lack the chemical information necessary to differentiate these varieties from an aroma perspective,” concluding simply that “the importance of terpenes appears to be overstated.”

For the purposes of this study, the research team analyzed “the volatile chemical profiles of 31 cannabis ice hash rosin extracts with a wide aromatic diversity using 2-dimensional gas chromatography coupled with time-of-flight mass spectrometry and flame ionization detection.” The results indicated “a myriad of nonterpenoid compounds that strongly influence the unique aromatic properties of cannabis.”

Interestingly, their findings show that while the majority of these nonterpenoid compounds occur in much smaller quantities than dominant terpenes, they punch way above their weight in terms of their effect on the plant’s aroma.

In particular, they identified “a new class of tropical volatile sulfur compounds (VSCs) that are major contributors to certain varieties with a strong citrus or tropical fruit aroma, while skatole (3-methylindole), a highly pungent compound, was identified as a key aroma compound in savory/chemical varieties.”

Ice hash rosin was used in this study because it has less plant tissue by weight than cannabis flower and further concentrates the molecules in question.

The rosin was then given to a sensory panel for analysis, with participants asked to group the samples into three categories: exotic fruity, prototypical, or exotic savory. These data provided researchers “with the framework to relate the chemical composition of each variety to their aromatic properties.” These results were then compared with chemical analysis to determine which compounds correlated with which perceived aromas.

Researchers “discovered that there exists [a] unique class of VSCs that produce tropical nuances–sulfur containing compounds that produce more citrus, fruity, sulfuric aromas–that includes 3-mercaptohexanol (3MH), 3-mercaptohexyl acetate (3MHA), and 3-mercaptohexyl butyrate (3MHB). These compounds have extremely potent aromas, comparable in strength to prenylthiol and prenylthioacetate. All three are found in a multitude of tropical fruits such as passionfruit and grapefruit. 3MH and 3MHA are also found in certain grapes and hops, which can translate to their presence in both wine and beer.”

In conclusion, the authors write that their results “yield a more complete understanding of the unique aromas that cannabis produces and help establish these nonterpenoid compounds as an important part of the phytochemistry of cannabis.”

And what’s more, “the discovery that terpenes have less influence on the differentiating characteristics of the aroma of cannabis than traditionally thought may have important ramifications for the legal cannabis industry related to product labelling and marketing, laboratory testing, and quality indicators for end consumers and producers alike.”

* The study cited above was conducted by a group of researchers associated with Abstrax Tech, an American company that specializes in the manufacture and sale of aromatic compounds from cannabis and other plants.

Related Articles

Of myrcene and mango: Questioning the entourage effect

June 8, 2022

138 cannabis samples tested by Health Canada in 2020, but no labs inspected

March 17, 2021

Increased terpene content leads to elevated release of degradation products for dabbing, decreases degradation in vape cart solutions

April 20, 2022

A study released earlier this year by researchers from the University of Alberta examined cannabis use for relief from discomfort associated with menopause. 

Published in BMJ Open in June, the study was led by Dr. Katherine Babyn at U of A’s Faculty of Pharmacy and Pharmaceutical Sciences. 

The study, which recruited people over the age of 35 who identify as women and reside in Alberta from various social media platforms, including Facebook and Instagram, notes that “a recent systematic review identified a lack of research on the effect of cannabis on menopausal symptoms. The increasing anecdotal use of cannabis for menopause symptoms demands more attention,” particularly in the Canadian context where cannabis has now been legal for several years.

The purpose of this particular study was not to investigate the efficacy of cannabis as a treatment for menopause symptoms, but rather to “characterise the use patterns and perceptions of cannabis specifically for menopause in a population of women aged 35 and over.” The study was conducted using a web-based survey over two months, from October to December 2020. 

The survey was comprised of 50 questions informed by existing published literature and Canadian cannabis surveys. Data collected included “demographics, medical history, self-reported changes to menstrual cycle and menopause symptoms, cannabis use,” and “respondents were asked about their perspectives related to cannabis, including use for menopause.”

The term ‘cannabis’ was used as a catch-all that included various forms, such as edibles, extracts, etc., that could contain any combination of cannabinoids, and the questions ranged from frequency and form of consumption to reasons for use and methods of access. 

Responses were analyzed from 1,485 women, 34 percent of whom reported currently using cannabis, while 66 percent reported ever having used it. The study notes that current cannabis users were more likely to report experiencing discomfort associated with menopause. 

“Majority of respondents identified as white (92.9 percent), had postsecondary education or higher (88.0 percent), and had at least a moderate level of health literacy (95.4 percent). Overall, 35.2 percent of women were in postmenopause and 32.7 percent in perimenopause. Most frequently reported symptoms were difficulty with sleep (65.3 percent), concentration (49.2 percent) and anxiety (48.8 percent).”

Many respondents, 73.5 percent, who used cannabis reported that it was helpful for their menopause symptoms. The most common forms of cannabis used were edibles and oils, followed by smoking. 

While women who reported current cannabis use were more likely to identify as medical users, women who only reported past use were more likely to identify as recreational users. 

The study concludes that while many women are using cannabis to treat discomfort associated with menopause, “further research is required to investigate the efficacy and safety of cannabis on menopause symptoms and foster the development of clinical resources for women to use in making informed decisions around cannabis for medical purposes.”

Researchers in Canada and the US are trying to teach your smartphone to know when you’re high. 

A new study recently shared online sought to see if artificial intelligence could be used to monitor cannabis intoxication in a more immediate way than other impairment-testing methods.

Researchers collected data from 33 people’s personal smartphone sensors and a Fitbit to monitor their heart rate, step counts, and sleep quality for up to thirty days, collecting information on their cannabis use (if at all), as well as other aspects of their mood, location, and activities.

About one quarter (24 percent) of participants reported using cannabis daily, 9 percent reported use 5-6 times per week, and one third (66.7 percent) reported use 2-4 times per week.

By having the participants self-report their cannabis use, they hoped to correlate feedback from the Fitbit and smartphone with cannabis use. Sensors on the participants’ phones also provided information on their “micromovements,” such as how they held their phones, in order to measure their stability and coordination.

Since smoking cannabis has been shown to cause an increase in resting heart rate, researchers hope to better distinguish between someone being intoxicated vs simply having THC in their system, and potentially being able to warn someone they are too impaired to drive, for example. 

The app collected data from the participants’ smartphones, which ran continuously in the background collecting information about their actions and behaviour, including conversations and background audio and lighting. Such features were only extracted from time intervals based on reported consumption to gain insight into the social setting of consumption. 

The Fitbit was used to collect information on heart rate, sleep, and steps. 

The app also allowed participants to enter reports of their cannabis use 15 minutes prior to smoking or vaping, and then later rate how high they feel on a scale of 1-10. They were also asked about how much they consumed and using what method, and to report when they then no longer felt high.  

One of the goals of the study was simply to understand if such data collection is a viable way to measure cannabis use and intoxication. Although researchers acknowledge numerous challenges ensuring the user-reported data on cannabis use like the degree and length of high, they conclude the approach can be beneficial in “real world” settings. 

Moving forward, they hope to refine their approach by improving the smartphone and Fitbit algorithms and collecting more complete data from larger sample sizes.

Despite fears that legalizing cannabis would lead to troubling increases in problematic cannabis use, a new study is once again showing these concerns were over-hyped. 

Anyone who was around post-2015, from the #toasterbud affair to the hysteria following Canadian Senator Nicole Eaton’s revelation that five grams of cannabis is equivalent to four tokes, is well aware that a certain subset of Canadian politics has been staunchly afraid that the only possible outcome of recreational legalization could be widespread reefer madness and the full-blown undermining of any semblance of cultural and/or economic normalcy that had been retained from the post-war boom, when everything was perfect for 15 or so years, and only degenerate criminals partook in the Devil’s Lettuce. <gasp>

Despite this hyperbole, as with any movement of great effect, there were an array of reasonable concerns surrounding legalization from rational parties. And now that recreational legalization has been demonstrating its effect for some time in many jurisdictions, researchers have some solid data to work with in analyzing the validity of these concerns. 

Earlier this month, a new study from researchers at the universities of Waterloo and Toronto examined one of these reasonable concerns: that of increased cannabis use disorder. 

For the purposes of this study, the presence of use-disorder was determined using the “Diagnostic and Statistical Manual of Mental Disorders criteria for cannabis dependence and abuse [8], the Cannabis Use Disorder Identification Test-Revised [9] and the World Health Organization Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) [10],” with researchers noting that “these scales typically assess a combination of frequent use as well as negative consequences on employment, social relationships and health.” 

The study also notes that in terms of non-problematic use, the number of people who had used cannabis once in the last month, last three months, or last twelve months, did increase. But was this also indicative of an increase in problematic use?

The short answer is no. 

The long answer is also no. 

Researchers screened groups of people of varying ages for problematic cannabis use in 2018, 2019, and 2020. In 2018, 89.1 percent of subjects were rated as low risk for problematic risk, versus 88 percent in 2020. 

Researchers concluded that “overall, in the initial period following legalization in Canada, levels of problematic use have changed very little at the population level.” 

Adding to this conclusion, researchers noted that “modest differences in problematic use risk scores were observed based on various socioeconomic indicators as well as race/ethnicity,”  indicating that “future research should continue to monitor the prevalence of problematic cannabis use indicators keeping these factors in mind to ensure that any potential drawbacks of legalization are not disproportionately impacting marginalized populations.” 

In the past, other studies have arrived at similar conclusions. This study from October of last year concluded that while “cannabis legalization in Canada was associated with a greater perception of cannabis harm among young people,” it was “also easier access.” This indicates that harm reduction messaging is having the desired effect, while ease of access to a regulated supply is ensuring that those who choose to partake aren’t putting themselves at mortal risk by doing so. 

Also, in 2021, The Journal of the American Medical Association published a survey of about 830,000 Americans that showed cannabis use did not increase in any significant way following legalization in any of the states that had chosen to do so at that point. 

So while the widespread recreational legalization of cannabis has certainly increased access, availability, and safety, at present it does not seem that this has precipitated the kinds of doomsday scenarios that Conservative Senators Gladu and Eaton raised alarm bells over back in the early days, or even anything resembling them.