CBD – what you need to know
There’s no question that CBD, also known as cannabidiol, is having a moment. From gummies to supplements, ingestible oils to creams, cannabis-derived products are quickly lining the shelves of high street pharmacies and health food stores.
Advocates claim CBD can help to cure chronic pain, alleviate anxiety and help us get a good night’s sleep. High concentrations are even being touted as the new side-effect-free solution to conditions as varied as epilepsy, ADHD, cancer and Parkinson’s.
Here, we take a closer look at CBD, where it comes from and whether there’s science to back up these bold claims.
What is CBD?
CBD is one of 113 cannabis chemicals (known as cannabinoids) that have been detected in the flowers of the Cannabis sativa plant. CBD is the second most abundant cannabinoid. This is just behind the infamous THC (or tetrahydrocannabinol), which is responsible for the ‘high’ associated with smoking marijuana.
While this psychoactive strain remains illegal in the UK, CBD isn’t associated with any such high and can be sold both online and on the high street.
Though very much the in-vogue supplement on the wellness scene today, cannabis has a long history of medicinal use. In fact, there’s evidence that its plant powers have been used as pain relief for many thousands of years, particularly by women.
It appears in the Ancient Egyptian Ebers Papyrus (1550 BC), which describes women preparing ‘oxymel’ (a mixture of cannabis and honey) to be inserted vaginally. Similar references are made in ancient Chinese and Ayurvedic texts. Cannabis doesn’t appear in Western medical literature until the 1800s, when it was a popular treatment for both period pain and sciatica.
Evidence suggests that it even found its way to Buckingham Palace. A royal physician reportedly prescribed cannabis to Queen Victoria to help treat her monthly cramps. Towards the end of the 19th century, cannabis was eclipsed by a new generation of pain-relief medications, such as aspirin and purified morphine. It continued to be used as a sleep aid until 1971, when it was removed from the list of UK-approved medicines due to inconsistencies in quality and delivery.
Why the sudden rise in popularity?
Cannabis-based medicines came back into the public consciousness in 2018 due to Billy Caldwell – a 12-year-old boy with severe epilepsy.
Billy’s family discovered that cannabis oil had a remarkable effect on his seizures (reducing both their intensity and frequency). In June of that year, Billy’s mother had seven bottles confiscated by UK Customs as she attempted to fly back from Canada. A media furore ensued. The family were eventually granted a temporary licence from the Home Office. The UK government promised to review the regulations surrounding cannabis-based medicines.
By the end of 2018 the law had changed. Medical cannabis was moved from being a schedule 1 drug (meaning it has no medical value) to a schedule 2 drug. This means doctors are now able to prescribe medicinal varieties under special circumstances.
How does CBD work?
Another reason for the renewed interest in cannabis is the remarkable discovery of the endocannabinoid system in the early 1990s. This is a network of previously undetected cannabinoid receptors that run through every organ and system in the body – from the brain to the immune system, reproductive organs to the gut.
We now know that our bodies produce a cannabinoid called anandamide (AEA). This binds to these receptors, influencing our mood, immunity, inflammatory responses and likely a host of other functions yet to be discovered. This opens the door to the possibility that one or many of the 113 cannabinoids in Cannabis sativa might also offer powerful therapeutic effects.
For now, the research is in its infancy. The discovery of the two main receptors (known as CB1 and CB2) helps to explain why CBD and THC have such profoundly different effects on the body. This is despite the fact that they have an identical molecular make-up (21 atoms of carbon, 30 of hydrogen and two of oxygen).
Though seemingly identical, the atoms in both cannabinoids form slightly different shapes (like jigsaw puzzle pieces). While both CBD and THC can bond with CB2 receptors, only THC can attach to CB1 receptors. This sends signals to the brain that result in a ‘high’.
What can CBD do?
When trying to understand what CBD might be able to do for us, it’s important to distinguish between two varieties. There’s the medicinal cannabis and the CBD oils, supplements and creams that you can purchase in popular health food stores.
There are currently only two medicinal cannabis drugs in the UK with sufficient evidence to support their use. The first is Epidiolex, which is used to treat very rare forms of epilepsy (Lennox-Gastaut syndrome and Dravet syndrome). The second is Sativex. This contains a combination of both CBD and THC, and is licensed for the treatment of multiple sclerosis.
These drugs aren’t available via a GP. Only a medical specialist on an approved register can prescribe them. The NHS is clear that, as the evidence stands, cannabis-based medicines can only benefit a very small number of patients. Specialists will only consider CBD when other first-line treatments fail.
We can therefore assume that the vast majority of the 1.3 million CBD users in the UK are using over-the-counter CBD. These shop-bought products contain the same active ingredient as medicinal cannabis (minus any traces of illegal THC) but at much lower concentrations.
The therapeutic benefits of CBD
Consumer reports show that pain is the primary reason why we’re reaching for over-the-counter CBD. This might be undiagnosed chronic pain; arthritic or joint pain; migraines, tension and cluster headaches or period pain.
This surge in interest points to an under-reported pain pandemic. Estimates suggest that 28 million people in the UK are living with pain. One in three of these are taking prescription pills to cope with their symptoms.
If CBD can offer relief it couldn’t be more timely. We expect that the number of people living with pain will rise as a result of our ageing population.
Despite glimmers of hope and significant quantities of anecdotal evidence, there are glaring gaps in the medical literature that has been gathered so far.
What the science says
One promising small randomised controlled trial of 24 patients found that 120mg of CBD dissolved under the tongue may help to treat neuropathic pain (pain associated with nerve rather than tissue damage). Two small uncontrolled studies (19 patients in total) found that 100-300mg of CBD taken orally may have a positive effect on neuropathic and post-operative pain. But a trial of 320 patients with osteoarthritis found that 250mg of CBD gel applied to the skin had no effect whatsoever on pain.
The National Institute for Health and Care Excellence (NICE) evaluated whether the NHS should prescribe cannabis-based medicine for pain. They found that there was some evidence that formulas containing THC alone or a combination of both CBD and THC could reduce chronic pain. The treatment effect, however, was ‘modest’ (an average improvement of about 0.4 on a scale ranging from 0 to 10).
When put through a cost-benefit analysis, the committee concluded that ‘the potential benefits offered were small compared with the high and ongoing costs, and the products were not an effective use of NHS resources’.
Stress, anxiety and depression
After chronic pain, stress, anxiety and depression are the second most common reason for purchasing an over-the-counter CBD product. Once again, there is much more anecdotal evidence supporting its use than scientific data.
There is some evidence that CBD can help to calm the cardiovascular response associated with stress and anxiety. A double-blind randomised controlled study of healthy men found that a high dose of CBD (600mg) reduced their resting blood pressure and the subsequent blood pressure increase when put under stress.
Another double-blind, placebo-controlled trial tested the effects of CBD on people with generalised social anxiety disorder. A single dose (600mg) taken before a simulated public speaking event significantly reduced anxiety, cognitive impairment and discomfort. The placebo group presented with much higher levels of anxiety.
A lower-quality study (with no controls or placebo) studied the clinical application of CBD for anxiety in 72 adult patients in a psychiatric clinic, when used as an adjunct to usual treatment. Anxiety scores decreased within the first month in 79.2% of cases and remained decreased for the duration of the study. With no controls, it’s difficult to say for sure that this effect was a result of taking CBD.
When it comes to depression, there is very little evidence to support the use of CBD.
Insomnia is the third most popular reason for purchasing CBD. It’s also another area that many people anecdotally report seeing dramatic improvements. Preliminary scientific research suggests that CBD might help to treat insomnia. Once again, the research is in its infancy and has yielded mixed results.
A study of rats showed that CBD increased the duration of sleep. Researchers are yet to replicate these reuslts in humans. A double-blind, placebo-controlled trial in 70 healthy people found that CBD reduced the time to fall asleep and improved sleep efficiency but the changes were not statistically significant. This means researchers were unable to definitively prove that this was not down to chance.
In a trial that measured the anxiety levels of 72 patients in a psychiatric clinic, researchers saw a moderate improvement in sleep scores in 66.7% of the patients. This improvement did not last for the duration of the trial, however. There’s simply not yet enough data to say whether CBD can improve the length or quality of our sleep.
How to source CBD
If you do decide to experiment with CBD, be sure to choose a reputable brand. CBD is barely regulated. Studies have revealed that some of the products lining our shelves are not at all what they seem.
Of 29 UK products blind-tested, only 11 contained within 10% of the claimed CBD content. One product retailing for a premium £90 contained no CBD whatsoever and over half contained detectable amounts of illegal THC.
When shopping for CBD, look out for the following:
Choose a product that uses organically grown Cannabis sativa. The plant accumulates heavy metals and other toxins in the soil that it grows in.
Ensure that the product has received or is working towards Novel Food Authorisation.
Choose a product that tests each and every batch of CBD extracted. This ensures CBD levels are as advertised and that there are no traces of THC. Ideally, look for brands who have reports independently verified by a third party.