The current popularity of cannabis is growing at an equal pace of the number of scientific studies conducted to thoroughly study its benefits on human and animal health. The results, for the moment, are more than promising and indicate the potentials of cannabis in a very clear way, for the treatment of a wide range of pathologies, from epilepsy to psoriasis.
Recently, cannabis and its main active principles – particularly cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC) – have been indicated as possible substances to be utilised during cancer therapy.
Cannabis is also used on patients affected by some form of cancer and is submitted to chemotherapy, but the modalities and the real reasons for this therapeutic application should be specified.
Can cannabis cure cancer or reduce the tumour mass?
No. Cannabis or its single active principles do not have any demonstrated role which, at the moment, suggests its effectiveness in contrasting the progress of a tumour.
Some research studies exist – all of them conducted on cells in a laboratory context or on experimental animals – which demonstrate how it might be possible that cannabinoids can have some effect on tumour cells, but currently there is no evidence that the substances contained in cannabis are able to cure the disease.
This possibility is studied and investigated with great obstinacy – in view of the benefits found in other fields – and it is possible that in future substances are discovered which are capable of a targeted action on tumour cells.
However, - considered the delicacy of the topic and the fact that enthusiastic proclaims without sound scientific bases have already disappointed patients and their families – it is necessary to emphasise that, according to the current medical knowledge, cannabis does not have any role in effectively contrasting the development and growth of tumours.
Differently and with unquestionably more solid scientific evidence, is the use made of cannabis as a palliative treatment or in contrasting some of the adverse effects of anti-tumoral treatments, like, for example, chemotherapy.
Cannabis and the endocannabinoid system
The human brain produces some substances similar to those contained in cannabis. They are known as endocannabinoids, substances allowing to understand the mechanism of action of cannabis.
Cannabinoids contained in cannabis, influence, among others, the receptor present in the brain called CB1, as they stimulate the two main endocannabinoids: anandamide and 2- arachidonoylglycerol, known as 2-AG.
The latter is an inhibitor of nervous cell excitation.
Anandamide, on the other hand, functions as a modulator of stress.
Many studies demonstrated the capability of cannabinoids – the active principles contained in cannabis – to exert a painkilling action (as a consequence of the regulation of the electric stimuli of neurons) and to contribute to recovering appetite in terminal patients or patients effected by severe and recurring nausea.
Cannabis against nausea, vomit and chronic pain
Cannabis and the single cannabinoids have been studied for the treatment of nausea and vomit caused by chemotherapy. According to one of the first studies aimed on investigating the use of cannabis in the field of oncology, cannabinoids used for treated the adverse side effects of chemotherapy showed to be more effective than other antiemetics.
In 2010 on the pages of the British Journal of Pharmacology the results of a study conducted by researchers of the Department of Psychology and Collaborative Neuroscience Program, at the University of Guelph, in Canada, were published. According to the authors, there is considerable evidence that the manipulation of the endocannabinoid system is able to control the sense of nausea.
The antiemetic effect of cannabinoids has been demonstrated on some animals: the action on the CB1 receptors would lead to suppressing the sensation of having to vomit. In particular, the primary non-psychotropic compound of cannabis, cannabidiol (CBD), suppresses also nausea and vomit in limited dosages.
Preclinical research indicated that cannabinoids, included CBD, can be clinically effective for treating both nausea and vomit resulting from chemotherapy or other therapeutic treatments.
Furthermore, science is demonstrating the potential of cannabidiol (CBD) to contrast chronic pain, more and more each day.
Its well-known anti-inflammatory effects have been the focus of various studies, suggesting its application as a complementary treatment to the palliative treatments of terminal cancer patients. Palliative treatments are therapies aimed on the mitigation of the symptoms of patients affected by an incurable disease.
What we know is that cannabinoids act on some typical ailments of those fighting against cancer.
Cannabinoids can help to recover appetite, stimulate a sensation of wellbeing, can have a myorelaxant action, can help to sleep, and, in general, can help a patient, requiring palliative treatments to feel better.
This is the reason for which cannabis, in Italy, was authorised for therapeutic purposes adjuvant to palliative treatments, without the intention, however, that this “opening” becomes synonym to the substitution of regular therapy.
Therapeutic cannabis and its active principles utilised in medicine have nothing in common with cannabis used for recreational purposes. For medical use it is necessary that the product is certified and that its components are declared with complete accuracy. Any palliative therapy with cannabidiol (CBD) must be agreed together with one’s physician, who will assess if it can be complementary to other ongoing treatments.
Cannabis, in conclusion, does not cure cancer but can certainly be utilised for some prescribed and authorised applications.