The 17 Most Compelling Studies on CBD
CBD – three little letters that just might revolutionize how people view medication and their options for treatment.
A survey from April of this year showed that 55% of Americans regularly take prescription medication. That percentage might not seem overly alarming because prescription medication has become so normalized.
However, the negative ramifications of prescription medications, including the exploding opioid crisis, underscore the sometimes-lethal consequences of our fixation on prescription drugs.
Unfortunately, many alternative options for treatment, i.e. homeopathic remedies, do not generally have the research or scientific support to be seen as a viable and effective alternative.
Over the course of this year (and many years prior) Cannabidiol has been shown to be a potential therapy for:
- Psychotic Disorders
- Stroke Rehabilitation
- High Blood Pressure
- Liver Injury
Also, study after study has demonstrated CBD does not get you high. As such, this powerful therapy should not be associated with rolling a joint to mellow out; it has real potential to be a legitimate treatment.
This is great news given that the conditions listed above are generally treated by prescription medication, which can cause severe side effects and opioid addiction.
CBD studies with the greatest impact over the past year
Over the past year, hundreds of CBD-related studies were conducted across dozens of countries and institutions. Many of them contribute to the growing understanding — and acceptance — of CBD.
We decided to call out 17 of the studies that stood out among the most important CBD studies of the year. While this is not a comprehensive list, it does highlight some of the critical studies conducted by important researchers in this field.
The studies discussed below continue to pave the way for alternative ways to medicate with CBD and voice urgent need for more research into CBD.
Table of Contents
- Can CBD Help Manage Fear?
- Afraid of Public-Speaking? CBD Might Help
- Potential Anti-Panic Actions of CBD
- Does CBD Reduce High Blood Pressure?
- Does CBD Get You High?
- CBD Doesn’t Make You Burn Through a Box of Oreos
- CBD’s Potential Lack of Effect on Anxiety
- CBD’s Relevance to Schizophrenia
- CBD and Opioid Use: First Long-Term Study
- CBD and Irritable Bowel Disease
- Liver Injury and CBD’s Potential Healing Effect
- A Potential Aid in Brain Recovery After a Stroke
- Pain and CBD’s Potential Effect
- What’s Next?
CBD Research Round-Up
Authors: Kerstin Iffland and Franjo Grotenhermen; nova-Institut, Hürth, Germany
A logical start to this list is an overall update on CBD. Published in June, this review evaluated a massive amount of existing research, data, and studies with the intent to update and synthesize vast amounts of data.
- CBD is safe to use
- There is a major need for more research as the majority of studies were performed for treatment of epilepsy and psychotic disorders
- Most common side effects reported are tiredness, diarrhea, and changes of appetite/weight.
- CBD has comparatively fewer side-effects compared with prescription medication
- The fewer side-effects could help increase patient-adherence to treatment
- CBD can be used as a supplemental therapy
To put the CBD side-effects in perspective, other drugs used for the same medical condition have far more negative side-effect profiles. This is particularly important as choosing a treatment with fewer side-effects could help ensure patients actually follow their treatment plans.
As to the safety of CBD use, the authors stated that the “safety profile is already established in a plethora of ways” and the breadth of their review serves to substantiate and build upon this notion.
CBD and Treatment-Resistant Seizures
Authors: G. Pesántez-Ríos, L. Armijos-Acurio, R. Jimbo-Sotomayor, S.I. Pascual-Pascual, G. Pesántez-Cuesta
Trial Parameters and Process
The parameters of this trial are particularly impressive and add to the integrity of the results:
- Subject pool of 120 children and young adults with Dravet syndrome and drug-resistant seizures
Over the course of a 14-week treatment period, the subjects were randomly assigned either a daily dose of CBD oral solution based on body weight or a placebo. The doses were given in conjunction with each subject’s standard antiepileptic treatment.
While the rate of non-convulsive seizures did not change, the CBD-treated convulsive seizures decreased from 12.4 to 5.9 percentage points – almost half. The placebo group only decreased by 0.8. In addition, 5% of patients who were given CBD became seizure free, compared with none in the placebo group.
It’s important to note that the CBD group did experience more severe side-effects, including vomiting and fever. However, these side-effects should be put in context. An astonishing 62% of the CBD group reported an significant increase in their overall condition, compared with on 34% of the placebo group.
The results are certainly compelling. However, the adverse side-effects warrant a more comprehensive, long-term study to investigate the continued use of CBD for Dravet Syndrome sufferers.
Can CBD Help Manage Fear?
Authors: Stern CAJ, da Silva TR, Raymundi AM, de Souza CP, Hiroaki-Sato VA, Kato L, Guimarães FS, Andreatini R, Takahashi RN, Bertoglio LJ; University of Parana, University of São Paulo, Federal University of Santa Catarina
Fear is something everyone can relate to. In fact, over 25 million people in the U.S. will experience PTSD at some point in their lives. This study looked at how CBD might weaken fear-response related to an adverse memory (like PTSD).
The results of this study, while based on fear in a more esoteric sense, do appear to suggest that CBD may one day play a vital role in the management of such a prevalent disorder.
The furry subjects, 277 Wistar rats, were given a dose of CBD immediately after receiving a small electric shock. The CBD-treated subjects were found to spend less time frozen in fear when reintroduced to the context of the fearful event. This means the CBD disrupted consolidation (or more simply put: memory strengthening) of their specific and long-term fear memory.
CBD was also found to disrupt the consolidation of generalized fear memories when administered immediately after the acquisition of such fear memory. Interestingly, the timing of the administration of CBD was vital as the results demonstrated that delayed administration of the CBD dose did not have the same effective result that immediate administration did.
The findings of this study could have a huge impact on PTSD management.
Afraid of Public-Speaking? CBD Might Help
Authors: Antonio W. Zuardi,Natália P. Rodrigues, Angélica L. Silva, Sandra A. Bernardo, Jaime E. C. Hallak, Francisco S. Guimarães, and José A. S. Crippa; University of São Paulo, National Institute of Science and Technology for Translational Medicine, National Council for Scientific and Technological Development
Fear of public speaking, also known as Glossophobia, is incredibly common and most people have experienced it at some point in their lives. This double-blind study involved a total of 60 males and females between the ages of 18 and 35.
The subjects were divided into 5 groups who randomly received either a placebo, CBD in 100mg, 300mg or 900mg, or clonazepam (a medication used to treat panic disorders) following the experimental procedure in the graphic below:
Each participant gave a speech in front of the other participants, after which he or she again filled out the questionnaire on anxiety level (see graphic) and again had his or her blood pressure and heart rate taken.
Clonazepam was the obvious front runner, consistently reducing anxiety in a more sedative way than the placebos and CBD administration. However, CBD at a dosage of 300mg was shown to significantly reduce subjective anxiety in the post-speech phase. The same was not true for the 100mg and 900mg dosage.
This study’s true focus was the varied dosage; seeking whether administration of CBD produces an “inverted U-Shaped dose response.”
We spoke with Antonio Zuardi, who told us this phrase “refers to a concept that a given drug is effective with an intermediate dose, but not with smaller or larger doses.” CBD did indeed produce such a response.
As such, Zuardi noted that “These findings stress the importance of the careful choice of dose ranges when investigating the potential therapeutic effects of CBD.”
The dosing is obviously vital but the real-life impact of this study is that CBD could be used to manage anxiety.
Potential Anti-panic Actions of CBD
Authors: Vanessa P. Soares and Alline C. Campos
This review opens strong, stating: “Panic disorder (PD) is a disabling psychiatry[sic] condition that affects approximately 5% of the worldwide population.” The percentage itself might sound small, but it is actually 355 million people. This is a staggering number of people who suffer from anxiety.
The authors analyzed prior human and animal studies to consolidate the information and make an overarching determination as to the therapeutic effect of cannabinoids, particularly, CBD. The article looked to a multitude of findings from prior studies such as human anxiety in public speaking and electrical stimulation in animal subjects.
Long story short, this article confirmed that CBD appears to be a promising treatment for panic disorders.
The most compelling conclusion is CBD is not habit-forming and doesn’t decrease tolerance. Thus, it could be a solid alternative for “high potency benzodiazepines and antidepressant drugs in PD patients who are resistant to the current treatments.”
This is incredibly encouraging not only for those with panic disorder but also those with varying types of anxiety who currently rely on psychiatric medications.
Does CBD Reduce High Blood Pressure?
Authors: Khalid A. Jadoon, Garry D. Tan, and Saoirse E. O’Sullivan
High blood pressure is a globally ubiquitous issue. This study explores the connection between CBD and a reduction in blood pressure. It is particularly unique as it is noted that “there are no dedicated studies in humans to date, to our knowledge, looking at the effect of CBD on either resting cardiovascular measurement or on the responses to stress, with continuous monitoring of CV parameters.”
In a randomized, placebo-controlled, double-blind, crossover study, nine healthy male volunteers were given either 600 mg of CBD or a placebo. They were then monitored for changes in their cardiovascular system.
Using stress tests, such as math without a calculator, cardiovascular outputs were monitored. The study found that CBD reduced resting systolic blood pressure and stroke volume. It also “blunted the blood pressure response to stress[….]”
High blood pressure has a multitude of potential treatments, including diet and exercise. This study essentially adds CBD to the list. The data from this research is also important as information for potential side-effects of CBD.
The Prior Studies
The first prior study analyzed the changes in CBD when mixed with a petri-dish simulation of stomach acids. Interpretation of the results yielded the researcher conclusion that CBD does convert to THC when exposed to stomach acids.
The second prior study also suggested CBD may convert to THC when taken orally. The conclusion was based on tests done on human volunteers.
The study authors noted that both prior studies were severely misinterpreted. This is due to two main reasons.
- While CBD might convert to THC under certain simulated acidic conditions, it has not been shown to actually occur in living organisms. This is a classic misinterpretation of what could happen in practicality based solely on culture-dish tests results.
- The results of the human volunteer tests were taken out of context. Traces of THC were not only extremely minimal in the human volunteers but the alleged THC was not present in urine samples.
Author Gerhard Nahler found it most surprising that an entire group of authors were “tempted to over-interpret results.” However, he felt that misinterpretations are not entirely uncommon, stating “People overlook quite frequently that “in vitro” results may differ significantly from conditions “in vivo”, particularly in man. In vitro results are suggestions, not proofs for processes in real life.”
The researchers note that while conversion to THC may occur under artificial conditions “Over 40 years of research on CBD does not suggest a conversion of CBD to delta9-THC and/or other cannabinoids in vivo after oral administration.”
To avoid misinterpretations in the future, Nahler noted “The more a result is unexpected (or presented as such as it was in the paper of Merrick et al., 2016) the more authors should be cautious when interpreting and extrapolating results.”
This is a truly impactful study for CBD use as it takes direct aim at the common-yet-faulty belief that CBD is a psychoactive compound.
CBD Doesn’t Make You Burn Through a Box of Oreos
Authors: Suzanne E.M. de Bruijn, Cees de Graaf, Renger F. Witkamp, and Gerry Jager; Wageningen University
In a test that involved giving volunteers chocolate milk to drink, this study sought the answer to a quirky question: Does CBD (or THC) affect how humans perceive “sweet taste.”
Spoiler: CBD does not.
Over the course of three test sessions the healthy volunteers were randomly given either a placebo, CBD, or THC and then got chocolate-wasted on several samples of chocolate milk, rating the sweetness after each.
The study found that while the THC stimulant did increase a desire to eat, the CBD did not have any effect or intervention on the subjects’ consumption.
This also helps support the prior study on this list (“CBD Does Not Get You High”) as it further debunks the notion that CBD has psychoactive effects, e.g. “the munchies.”
CBD’s Potential Lack of Effect on Anxiety
Authors: David L. Arndt and Harriet de Wit; University of Chicago
The core findings of this study is that CBD does not mute or alter the user’s mood or anxiety.
Over the course of this double-blind, placebo-controlled study, 38 participants were given either a placebo or variable dose of CBD. The participants then had to complete tasks that allowed for analysis of their level of emotional “reactivity.” The tasks included:
- Perceptual sensitivity to emotional facial expressions
- Attentional bias toward emotional facial expressions
- Feelings of social rejection
This is obviously a rollercoaster of a study which found that the ups and downs of the ride did not change based on whether the participant received a placebo or CBD. The results demonstrate that CBD did not affect the subject’s anxiety.
Author Harriet de Wit found it particularly surprising that they “were unable to detect any effects of this drug, even though we went to high doses.” This indicates that CBD has, at most, a marginal effect on a user’s responses to emotional triggers.
Again, this can be good news or bad depending on the point of view: The good: CBD might not affect how one emotionally views the world, which is great because that is one side-effect less to a potential health therapy.
CBD’s Relevance to Schizophrenia
Authors: Osborne AL, Solowij N, Weston-Green K; Illawarra Health and Medical Research Institute, University of Wollongong
Schizophrenia is a disorder that generally requires heavy antipsychotic drugs just to manage daily life. However, this systematic review notes that such drugs “provide limited cognitive benefits,” which is extremely rough given the side effects antipsychotic drugs can have. As discussed in the review, CBD may be a possible alternative to such heavy prescription drugs.
CBD has both anti-inflammatory and anti-psychotic characteristics. Thus, the aim of the review was to evaluate literature (both preclinical and clinical) on the effects of CBD in relation to schizophrenia. The authors looked through 27 articles from the past 26 years.
The overarching theme of the literature demonstrated that CBD “improves cognition in multiple preclinical models of cognitive impairment,” which includes:
- Alzheimer’s disease
- Neuro-inflammatory conditions (e.g.: Fibromyalgia)
- Neurological disorders (e.g.: Epilepsy)
Due to the lack of clinical evidence, the level and effectiveness that CBD might have cannot be clearly stated. The review is nonetheless an excellent starting point for the future use of CBD in neurological treatments.
CBD and Opioid Use: First Long Term Study
Authors: TBD; Albert Einstein College of Medicine and Montefiore Health System
Full disclosure, this is not a published study yet, but the announcement itself is worth including in this list. A 5-year $3.8 million grant was awarded to conduct an 18-month study that will seek to answer whether CBD reduces opioid use among adults with chronic pain.
The study will include adults with HIV as this group, compared with the general public, has higher levels of chronic pain and opioid use.
This is particularly exciting news as it is the first long-term study of this question.
CBD and Irritable Bowel Disease
Authors: Leinwand, Kristina L. DO; Gerich, Mark E. MD; Hoffenberg, Edward J. MD; Collins, Colm B. PhD; National Institutes of Health T32 Institutional Training Grant in Pediatric Gastroenterology; National Institute of Diabetes and Digestive and Kidney Diseases at the National Institutes of Health; Colorado Department of Public Health and Environment
Once diagnosed with Inflammatory Bowel Disease (IBD), a person begins a lifelong battle as there is currently no cure. As noted in this review, while modern medicine does tend to allow people to live relatively normal lives, the medicines used to treat IBD can have limited benefits and lose effectiveness.
The review evaluated how targeting the Endocannabinoid System (ECS) could impact colitis. The ECS is a biological system within mammals that is made up of three components: cannabinoid receptors (the things that receive chemical signals outside the cell), endocannabinoids (small molecules that activate cannabinoid receptors), and metabolic enzymes that break down endocannabinoids after they are used.
Results indicated the two main cannabinoid receptors (CB1 and CB2), along with endocannabinoids and atypical cannabinoids are “upregulated in inflammation, and their presence and stimulation attenuate murine colitis.” Put simply: manipulating the ECS can provide substantial relief from colitis.
The review notes that incidents of IBD are on the rise, which reinforces the need for research into new potential therapies. Additionally, IBD results in “an estimated annual disease-attributable direct cost in the United States in excess of $6.3 billion.” That’s 6.3 billion reasons to continue exploring novel therapies.
Liver Injury and CBD’s Potential Healing Effect
Authors: Yuping Wang, Partha Mukhopadhyay, Zongxian Cao, Hua Wang, Dechun Feng, György Haskó, Raphael Mechoulam, Bin Gao, and Pal Pacher; National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Affiliated Hospital of Guiyang Medical University, Rutgers New Jersey Medical School, Hebrew University
This study investigated how CBD could affect subjects with liver injuries resulting from chronic and binge alcohol consumption. CBD was given to subjects (in this case, mice and human blood samples) that had been fed alcohol. In short, the analysis demonstrated that CBD lessened the elevated liver enzymes and the increased liver triglyceride. It also reduced fat droplet accumulation.
Also of note, CBD improved the alcohol-induced liver metabolic impairment and abnormal retention of lipids. Essentially, CBD may be a potential therapeutic treatment for alcoholic liver diseases “associated with inflammation, oxidative stress and steatosis.”
A Potential Aid in Brain Recovery After a Stroke
Authors: Ceprián M, Jiménez-Sánchez L, Vargas C, Barata L, Hind W, Martínez-Orgado J; Universidad Complutense de Madrid; Instituto de Investigación Puerta de Hierro Majadahonda, Instituto de Investigación Puerta de Hierro Majadahonda; GW Research Ltd; Instituto de Investigación Puerta de Hierro Majadahonda
Arterial Ischemic Stroke occurs when blood flow in an artery to the brain is blocked due to narrowness of the artery or the formation of a blood clot. Neonatal (i.e. newborn) Arterial Ischemic Stroke grimly means there is a condition specific to infants. Woefully little is known about NAIS, but it can certainly lead to lifelong disabilities and/or brain injury. Currently, there is no effective treatment.
This study demonstrated CBD can reduce brain damage and improve recovery, at least in the neonatal Wistar rat subjects studied. Analyzing the effects to the brain via MRI, behavioral tests, and other system studies, the researchers found that CBD administration after induced artery blockage led to “long-term functional recovery.”
CBD reduced all of the following: the loss of neuronal structure and function, the abnormal increase of astrocytes (a certain type of cell in the brain), cell death and damage, and inflammation of the nervous tissue.
With more clinical studies this treatment could become a reality for human newborns.
Pain and CBD’s Potential Effect
Authors: Karina Genaro, Débora Fabris, Ana L. F. Arantes, Antônio W. Zuardi, José A. S. Crippa, and Wiliam A. Prado; University of São Paulo; National Institute of Science and Technology for Translational Medicine
Pain is multidimensional; it is “an experience that has somatosensory, affective, motivational and cognitive characteristics.” Pain also affects several regions of the brain, which makes the relationship between pain and perception difficult to analyze.
This study analyzed whether the application of CBD has an effect on pain in the varied ways it can be perceived and experienced. The research yielded several results. Most notable was “systemic” application of CBD reduces mechanical allodynia in the injured subjects.
The researchers concluded that there is evidence “CBD influences different dimensions of the response of rats to a surgical incision.” This is one of the first studies to show that CBD can have an effect on the perception of pain, which paves the way for future research in this area.
The findings from these studies are broad, ranging from treatment of serious disorders to quirky ancillary information. Ultimately, these aren’t the first studies to be done on the efficacy of CBD as a medical therapy.
Fundamentally, the true importance of these studies and reviews is the fact that many of them, and the researchers behind them, are building from earlier findings, theories, and research efforts.
Their impact is not only the actual results but the way those results echo into the CBD research field. These studies are a call to action, reflecting the vast need to dig deeper into the potential benefits of CBD as an alternative treatment for so many disorders.
More research, trials, and studies are needed to fully understand the long-term effects and benefits of this potentially game-changing way to approach treatments. This year was progressive in changing the perception of cannabidiol and highlighting its potential uses; here’s looking to 2018 to continue working toward research growth!
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These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.