Although drugs containing cannabidiol oil are currently being used in Europe, they have not yet been approved for use in the United States because the clinical evidence supporting its efficacy is still lacking.
According to this summary presented by Nora D. Volkow, director of the National Institute on Drug Abuse and presented to the Senate Caucus on International Narcotics Control, more testing is needed before this drug will make its way into mainstream use in the U.S.
For those who never heard of it, Volkow describes CBD as one of more than 80 active cannabinoid chemicals that are found in the marijuana plant. However, unlike THC (tetrahydrocannabinol) which is the ingredient that makes people “high”, CBD produces no euphoria or intoxication of any kind.
“Cannabinoids have their effect mainly by interacting with specific receptors on cells in the brain and body,” Volkow writes.
During her testimony, Volkow lists the potential uses of CBD and where the science currently stands on each:
While there have been a number of studies which found that CBD has reduced the severity of seizures in animal models, there have only been a few small randomized clinical trials examining its use in the treatment of epilepsy. The total number of subjects enrolled in these studies was only 48 and even though three out of four studies reported positive results, the studies had “significant” design flaws.
“Therefore, the currently available information is insufficient to draw firm conclusions regarding the efficacy of CBD as a treatment for epilepsy,” Volkow reports.
Neuroprotective and Anti-Inflammatory Effects
CBD has shown neuroprotective properties in cell cultures and animal models which could help in the treatment of diseases such as Alzheimer’s, stroke, multiple sclerosis and Parkinson’s disease. A drug known as Nabiximol (trade name Sativex) which contains both THC and CBD in “roughly equal” proportions has been approved for use in Europe for the treatment of symptoms associated with MS. Clinical trials in the U.S. are ongoing with some success but these studies are limited and a recent trial producing positive effects in patients with Parkinson’s was described as being “small” meaning much more research is needed.
There have been multiple clinical trials demonstrating the efficacy of nabiximols on central and peripheral neuropathic pain, rheumatoid arthritis, and cancer pain, Volkow reports. The drug is approved in Canada for MS and cancer-related pain that does not respond to opioid therapy.
“However, the current evidence suggests that the analgesia is mediated by THC and it is unclear whether CBD contributes to the therapeutic effects,” Volkow writes. Because THC alone has been shown to reduce pain, there are no clinical studies that have explored the efficacy of CBD alone on pain.
There have been pre-clinical reports showing anti-tumor effects in cell culture and animal models, but these effects could be due to the anti-oxidant and anti-inflammatory effect of CBD. It’s also important to note that there has not yet been any trial involving human patients, although they are underway at the current time.
“There have been a few small-scale clinical trials in which patients with psychotic symptoms were treated with CBD, including case reports of patients with schizophrenia that reported conflicting results,” Volkow writes.
She cites a small case study in patients with Parkinson’s disease with psychosis which reported positive results, and another small randomized clinical trial reporting clinical improvement in patients with schizophrenia treated with CBD.
“Large randomized clinical trials would be needed to fully evaluate the therapeutic potential of CBD for patients with schizophrenia and other forms of psychosis,” she surmises.
CBD has shown some positive effects in a range of anxiety and stress levels in animals, and small human laboratory and clinical trials have produced good results. However, as Volkow reports, “the anxiety-reducing effects of CBD appear to be mediated by alterations in serotonin receptor 1a signaling, although the precise mechanism remains to be elucidated and more research is needed.”
Treatment of Substance Use Disorders
Early preclinical findings also suggest that CBD may have therapeutic value as a treatment of substance use disorder but the available data is not sufficient to draw conclusions. Clinical trials are ongoing.
Volkow points out that while a review of 25 studies on the safety and efficacy of CBD did not identify significant side effects, “additional safety testing among specific patient populations may be warranted . . . “
She concludes: “While there is preliminary evidence that CBD may have therapeutic value for a number of conditions, we need to be careful to not get ahead of the evidence. Ninety-five percent of drugs that move from promising preclinical findings to clinical research do not make it to market.”
This is why consumers must be wary of any website that promotes CBD oil as a cure for anything. In fact, the FDA has sent warning letters to numerous companies who sell the oil along with promises of curing, treating or preventing various diseases.
For example, in a letter sent to CBD Life Holdings in Arizona, the FDA cited sections of the company’s website which listed studies they claim support the use of CBD for combating diseases such as neurodegenerative disorders and cancer.
“When scientific publications are used commercially by the seller of a product to promote the product to consumers, such publications may become evidence of the product’s intended use,” the FDA explained, which means CBD Life Holdings was presenting its product as a drug to the consumer when in reality it did not have this kind of approval.
“New drugs may not be legally introduced or delivered for introduction into interstate commerce without prior approval from the FDA…”
In addition, the FDA tested many of these products and found, in some cases, that they didn’t even contain CBD.
They conclude: “It is important to note that these products are not approved by FDA for the diagnosis, cure, mitigation, treatment, or prevention of any disease, and often they do not even contain the ingredients found on the label. Consumers should beware purchasing and using any such products.”
The bottom line is that although research is ongoing, there is simply no evidence to support the claims being made by many sellers of CBD oil. The use of this product in lieu of established treatment for any contagious and/or life threatening disease is against the teachings of the Catholic Church because it poses a danger to the health of both the individual and the community.