Over the last year or two, the buzz around cannabidiol (CBD) has skyrocketed. Once a fringe product most commonly sold as ‘hemp seed oil’, it has well and truly hit the mainstream. Consumers can purchase a staggering array of CBD-infused products, ranging from edible gummies to sprays; even to cosmetics are tapping into the growing market.
A non-psychoactive component of the cannabis plant, CBD has been billed as having many of the same health benefits as medical cannabis. But, despite the legalisation of medical cannabis in many parts of Europe, the product remains difficult for patients to access, meaning many would-be users are self-medicating with CBD.
Unfortunately, even with the growing body of evidence supporting its health benefits, CBD is currently sold as a food supplement, not a medicine. This means manufacturers are not allowed to make health claims around their products, and it can sometimes be hard for consumers to gauge what they are getting.
“While those in the industry, medical professionals and the public all seem to be in favour of CBD as a medical product, the stringent regulatory barriers in place before any product can be fully licensed require, quite rightly, extensive testing and trials,” explains Dr David Dawit, chief scientific officer at CBD production and testing company Eos Scientific. “The future of CBD looks incredibly promising in the UK medical arena, but the introduction of more fully licensed products most likely will not happen any time soon.”
What are the indications?
This being the case, the potential medical applications of CBD are very much open to discussion. As Rob James, managing director of CBD producer Cannuba, explains, research in the field was long stymied by the prohibition of cannabis. While the compound was first isolated in 1942, its therapeutic potential was not explored until much later.
“Due to its years in the illegal wilderness, there is very little in the way of hard scientific evidence for the efficacy of cannabis and its many constituents,” he says. “Until recently it has been almost impossible to carry out thorough randomised controlled trials, thus most academic research has been confined to vivo and vitro studies.”
That said, there are already some areas in which the evidence base is strong.
“Recognised clinical data has shown conclusive therapeutic benefits within chronic pain, chemotherapy-induced nausea and vomiting, and multiple sclerosis spasticity,” says James. “There is fair-to-good evidence that cannabinoids are effective treatments for sleep disorders, stimulating appetite, Tourette’s syndrome, anxiety, PTSD, brain injury, dementia and glaucoma.”
More broadly, people use CBD to treat three main types of ailments: pain management, complex motor disorders and mental health issues.
“I think what makes the market for CBD oil so interesting is that CBD specifically treats what have previously been widely overlooked medical conditions,” says Caitlin Rimmer, who works on behalf of the online retailer CBD Health Store. “It is only recently that people with mental health issues or severe, long-term pain have begun to be truly served by the medical community.”
There is also one medically-licensed CBD product, Epidiolex, which has been approved in the US for treating certain types of seizure. This is related, albeit not identical, to the ‘cannabis oil’ used to treat severely epileptic children, however, the latter product has proven more contentious, since it also contains small amounts of THC.
How does it work?
So how does CBD affect the body? The simple answer, according to Dawit, is that it ‘tops up’ the body’s endocannabinoid system.
“The human body naturally creates cannabinoids, which are used by the endocannabinoid system to maintain homeostasis,” he says. “The endocannabinoid system has been long regarded as the most important system in the body for maintaining long term health.”
James adds that the phytocannabinoids found in cannabis are remarkably similar to, and in some cases the same as, our own endocannabinoids.
“The isolation of CBD and THC led to the discovery of receptors in the body,” he says. “At present, we know the two main receptors, which are referred to as CB1 and CB2. THC and CBD bind to these receptors, creating neurosignals within the brain and organs. THC binds to CB1 receptors, found predominantly in the brain and nervous system whilst CB2 receptors occur mainly in the immune system and organs.”
While CBD does not bind well to either of these receptors, it does impact them indirectly. As of 2015, more than 65 molecular targets for CBD had been reported in the literature, and a number of researchers are looking to examine its mechanisms in greater detail.
It has been postulated, for instance, that its anti-anxiety effect is due to activation of the 5-HT1A serotonin receptor. This means it works via a different neural pathway to existing anti-anxiety medications like benzodiazepines, which target the GABA system. In one study, patients on benzodiazepines were initiated onto medical cannabis therapy. Nearly half were able to discontinue their benzodiazepine use after six months.
“CBD is most commonly used to self medicate amongst people with PTSD and anxiety,” says Rimmer. “This is an area that’s been very extensively tested with very promising results. Compared to other drugs for anxiety treatment, the effects can be felt as soon as your body absorbs it, rather than after several days of treatment.”
CBD also binds to TRPV1 (vanilloid) receptors, which affects the perception of pain. Interestingly, this receptor has been a prime target for drug developers looking to develop pain relief drugs. Given the scale of the opioid crisis, there is a dire need for non-addictive analgesics of this nature.
“The highly complex interactions between cannabinoids and their receptors will almost certainly reveal more discoveries in the near future and further on,” points out James.
The future of CBD
Clearly, these are exciting times for the CBD market. Dawit believes the future for CBD is bright, with big name retailers such as Holland & Barrett and Boots ready to stock a broader range of CBD products.
“The commoditisation of holistic remedies, made from natural ingredients, has become an exciting avenue for retailers, researchers and medical professionals to explore,” he says. “We at Eos Scientific are excited to be a part of this journey, believing our inclusion will help to grow the industry.”
All this said, it’s important to sound a note of caution. There is still a dearth of large, long-term studies, and many questions remain unanswered. (As the old adage goes, ‘the plural of anecdote is not data’ – an important counter to some of the more overblown claims online.)
“It is generally believed that CBD is safe, and to date there is no evidence of overdose or any significant side effects,” says James. “That being said, at present the market for CBD products is unregulated which has led to concerns over the quality and reliability of CBD formulas.”
He believes that, looking to the future, there is little doubt that CBD will grow in popularity and that, pending further studies, we will see more fully licensed pharmaceuticals. Here, it’s really just a matter of time.
“The implementation of any new pharmaceutical is a long path, so I can’t see the NHS offering CBD for anxiety or pain management in the next few years, but it will happen within our lifetimes,” Rimmer explains.