Cannabis is comprised of hundreds of ingredients, but the general public knows only two of them: tetrahydrocannabinol (THC) and cannabidiol (CBD). The common belief is that the THC ingredient is the only one responsible for the psychoactive effects of cannabis, such as a feeling of euphoria (“high”), anxiety, the onset of schizophrenia, and more. This is while CBD is perceived as a “safe” ingredient that does not cause such effects and even moderates the side effects of THC in cannabis. Moreover, it is believed that CBD also has anti-inflammatory effects and effectively reduces pain intensity. Are these perceptions backed by clinical studies?
What is the difference between THC and CBD?
THC and CBD are the most studied cannabinoids in the field of medical cannabis. It is a plant that fascinates humanity and has served it in the medical and recreational fields for thousands of years. Myths and beliefs existed in the world long before science did, and in contrast to science that speaks only of empirical facts and is accessible mainly to the medical professionals who engage in it, myths have a tendency to intensify and become established as truths that may harm the health of patients who wish to have cannabis affect their disease symptoms without suffering from side effects.
There is a significant gap in the public discourse on medical cannabis between the information presented to the public and the scientific and medical research findings. It is enough to read the posts on social networks to understand how big the gap is. And when most of the cannabis market belongs to recreational consumers and not to patients, beliefs and myths are entrenched in line with the results of clinical studies.
This perception could not be further from the truth. There are holes in the myth of the effectiveness of the CBD ingredient in reducing pain, and several studies from 2022 have shown that this myth is not true1,6, at least not to the same level of pain reduction that can be achieved with THC-rich products. Studies show that CBD may increase the risk of experiencing withdrawal symptoms, pneumonia, decreased appetite, and diarrhea2. Additional studies have shown that CBD is also associated with severe side effects, even if rare: an increase in liver enzymes, confusion (sedation), exhaustion (lethargy), and infections in the upper respiratory system when combined with certain drugs5. In another study, the researchers showed that CBD causes side effects usually associated with THC consumption, such as dizziness, sleepiness, nausea, impaired memory, impaired orientation, and more4.
Does CBD really reduce the side effects caused by THC?
One of the most established and interesting myths among cannabis users is that adding CBD to a treatment regimen with THC-rich cannabis can help reduce the side effects associated with THC, especially the psychoactive side effects. Are there any scientific facts that support this myth?
The origin of the myth is an animal study that examined the relationship between CBD and its ability to reduce the side effects of THC. In medicine, it is customary to draw conclusions about the safety of any type of treatment, including CBD, out of data from studies conducted on humans. What works with mice does not necessarily work with humans.
Psychiatric researchers in London decided to test the reliability of this myth. Their research was published in an article in the Neuropsychopharmacology Journal in June 20223. The researchers recruited 46 healthy subjects for a controlled study (it cannot be considered a clinical study because the participants were not sick). It was a randomized, double-blind, cross-over trial – a study in which all subjects in all test groups received all the treatments, in alternating order, without the researchers or the subjects knowing which group received which inflorescence and when.
The four groups had a singular session of cannabis administration by inhalation using a Volcano Vaporizer:
- Inhalation of cannabis that contains 10 mg THC and 0 mg CBD (0:1 ratio)
- Inhalation of cannabis that contains 10 mg THC and 10 mg CBD (1:1 ratio)
- Inhalation of cannabis that contains 10 mg of THC and 20 mg of CBD (2:1 ratio)
- Inhalation of cannabis that contains 10 mg of THC and 30 mg of CBD (3:1 ratio)
The doses in the study were prepared from combinations of the adherent cannabis strains of the highest quality (Bedrocan® and Bedrolite®) grown by the Dutch company Bedrocan.
The main indices tested:
- Difference in cognitive function (short-term memory) using a questionnaire
- Severity of psychotic symptoms as reported by the subjects
- Subjective indices, such as enjoyment
- Empirical indices: THC and CBD levels in the blood, before and after each inhalation, in periods of 5, 15, and 90 minutes*
The researchers described an attempt to standardize the inhalations using the balloon of the Volcano Vaporizer so that the administrated dose between subjects would be the same**.
The results of the study showed that inhaling THC-rich cannabis without CBD resulted in a significant worsening of short-term memory (3 points change compared to pre-inhalation level) and of the severity of psychotic symptoms. This result is neither surprising nor new; The innovation shown by the study results is that the same worsening also happened when CBD was combined in increasing ratios. Even a 3:1 ratio in favor of CBD did not moderate the effects attributed to THC.
The myth was finally broken: adding CBD to treatment with THC does not moderate the effects of THC. The researchers went even deeper and demonstrated that the higher the dose of inhaled CBD, the higher its average level in the blood. And at any level – even the highest – it did not affect the THC levels in the blood (neither increased nor decreased them), resulting in the refutation of this hypothesis as well.
Recent high-level research refutes thousands of years old myths
“In the last decade, we have witnessed fascinating changes in the field of medical cannabis in Israel and around the world.” Says Dr. Joshua (Shuki) Aviram, Clinical Research Director at Syqe® company. “Collecting high-level research data from many sources allows us to refute myths that have existed for decades, hundreds, and even thousands of years. However, it is important to emphasize that due to the multitude of “strains” that exist in pharmacies, strains that change from season to season and from month to month in the concentrations of their active ingredients, alongside the fact that the way each of us breathes is unique and differs from person to person – it is currently impossible to make medical cannabis treatment standardized in a way that characterizes the world of medicine: stable treatment with a uniform and consistent effect with each administration. And the more the “strains” there are, the more the myths intensify and circulate among patients and doctors.”
The only unique solution is the SyqeAir Inhaler which allows patients to inhale a consistent and precise dose from inflorescence that mainly contains THC. SyqeAir’s ability to minimize the side effects stems from the low dose (in mcg), which is personally adjusted to the patients in a gradual process. “With the new evidence, mainly from the British study3 conducted with Bedrocan inflorescences – the ones that we at Syqe® put into the cannabis Cartridges loaded into our Inhaler (Sativa T20C4) – it can be deduced that adding CBD probably does not increase the effectiveness or safety of the treatment that includes THC.” Dr. Aviram concludes.
* The level of components in the blood scientifically verifies symptoms, effects, and subjective indices.
** The chance of standardization with the same dose of all subjects among themselves and of each subject in each of the inhalations they performed is minimal when it comes to vaporizers or cannabis cigarettes.
The article was published on e-Med website on January 29th, 2023. Link to the article in Hebrew>>
References:
[1] Arnold JC, Mcgregor IS. The safety and efficacy of low oral doses of cannabidiol: An evaluation of the evidence. Clin Transl Sci 2022:1–21.
[2] Chesney E, Oliver D, Green A, Sovi S, Wilson J, Englund A, Freeman TP, Mcguire P. Adverse effects of cannabidiol: a systematic review and meta-analysis of randomized clinical trials. Neuropsychopharmacology 2020:0–22. doi:10.1038/s41386-020-0667-2.
[3] Hodsoll J, Fusar-poli P, Strang J, Murray RM, Freeman TP, Mcguire P. Does cannabidiol make cannabis safer? A randomised, double-blind, cross-over trial of cannabis with four different CBD: THC ratios. Neuropsychopharmacology 2022:1–8.
[4] Irving PM, Iqbal T, Nwokolo C, Subramanian S, Bloom S, Prasad N, Hart A, Murray C, Lindsay JO, Taylor A, Barron R, Wright S. A Randomized, Double-blind, Placebo-controlled, Parallel-group, Pilot Study of Cannabidiol-rich Botanical Extract in the Symptomatic Treatment of Ulcerative Colitis. Inflamm Bowel Dis 2018;24:714–724. doi:10.1093/ibd/izy002.
[5] Dos Santos RG, Guimarães FS, Crippa JAS, Hallak JEC, Rossi GN, Rocha JM, Zuardi AW. Serious adverse effects of cannabidiol (CBD): a review of randomized controlled trials. Expert Opin Drug Metab Toxicol 2020;16:517–526.
[6] Vela J, Dreyer L, Petersen KK, Arendt-Nielsen L, Duch KS, Kristensen S. Cannabidiol treatment in hand osteoarthritis and psoriatic arthritis: a randomized, double-blind, placebo-controlled trial. Pain 2022;163:1206–1214. doi:10.1097/J.PAIN.0000000000002466.
