Medical cannabis: the science beyond the stigma

Despite having been illegal for almost a century, cannabis remains one of the most researched therapeutically active substances in history. To date, there are more than 36,000 peer-reviewed scientific articles that refer to its cannabinoids. In recent years, this volume of research has grown exponentially even though the debate about its legalisation continues to stagnate in a number of countries, many of which refuse to understand that cannabis holds a medicinal potential that transcends the controversy that continues to haunt it.

Humans have cultivated and consumed cannabis since practically the beginning of recorded history. This plant was even used in the oldest traditional medicinal practices ever known. However, negative attention has prevailed over the last century, particularly with regard to its psychotropic and abusive effects, which is why cannabis is still considered an illegal substance in many countries.

In recent years, there has been a deeper evaluation of the usefulness of cannabinoids for medical purposes after the emergence of a large number of effectiveness reports backed by scientific evidence. Nonetheless, uncertainty remains in the medical community, which is partly derived from the legislative restrictions that have severely limited the development of rigorous, controlled, and comparable studies.

What is the current status of research on medical cannabis?

As clinical research into the therapeutic value of cannabinoids has further expanded, so too has the scientific understanding of the remarkable ability of cannabis to combat various pathologies. Whilst the researchers of the last decades of the 20th century mainly evaluated the ability of marijuana to relieve the symptoms of various diseases (such as chemotherapy-induced nausea), today’s scientists are exploring the potential role of cannabinoids to directly modulate these diseases.

For instance, the ability of cannabinoids to moderate certain autoimmune disorders is currently being investigated. These illnesses include multiple sclerosis, rheumatoid arthritis, and inflammatory bowel disease. Moreover, its role in the treatment of neurological disorders such as Alzheimer’s or amyotrophic lateral sclerosis is also being researched.

In addition, researchers are also studying the anti-cancer action of cannabis, as preclinical data have concluded that cannabinoids can reduce the spread of specific cancer cells through apoptosis (i.e. programmed cell death) and by inhibiting angiogenesis (i.e. the formation of new blood vessels).

The use of cannabis as an alternative for pain relief is also being explored. To date, dozens of studies have documented its use as an alternative to various prescription drugs, particularly opioids.

These recent discoveries arguably represent a vision of the applications of cannabinoid therapy that is much more significant and far broader than many researchers could have ever imagined only a few years ago.

The safety of cannabis for therapeutic use

Cannabinoids have a remarkable safety record, especially when compared to conventional drugs. Most significantly, marijuana consumption, regardless of quantity or potency, can never lead to a fatal overdose.

Furthermore, the use of cannabis for therapeutic purposes is rarely associated with significantly adverse side effects. A more recent scientific review concludes that “among the average adult user, the health risks associated with cannabis use are likely no more dangerous than many other indulgences”, including paracetamol use.

Recently, international organisations have also endorsed the therapeutic properties of cannabis by lowering its grade within their classification of narcotic drugs. These include the World Health Organisation (as stated in its June 2019 report), and the United Nations, which officially recognised the medical use of cannabis in December 2020. In turn, more than 45 countries, including Germany, Canada, several US states, and Israel, have already regulated the use of cannabis for medicinal purposes.

That said, cannabis should not be seen as a harmless substance. Its active components can produce a variety of physiological and mood-altering effects. As a result, some groups may be more vulnerable than others, for instance teenagers, pregnant women, or patients who have a family history of psychiatric illnesses or who have a high risk of developing a psychotic disorder.

Patients with a history of cardiovascular disorders may also have an increased risk of experiencing adverse side effects, particularly when smoking cannabis. Therefore, as with any medication, patients should consult with a doctor before deciding whether cannabis is a suitable and safe option for them.

A bright future for medical cannabis

Although the majority of scientists agree on the medical potential of cannabis, in most countries the legislation often lags behind the science. This leaves many doctors without the necessary tools to justify its use, which results in many patients being left without hope.

To prescribe cannabis correctly, physicians need clinical data on the right dosage, formulation, and method of administration, as well as information on how the side effects may vary between patients. Sadly, the classification of this plant as an illegal substance in many parts of the world inhibits this much needed research on cannabis.

However, as countries continue to pass more legislation for the use of physician-supervised medical marijuana, more patients suffering from a range of diseases are taking this opportunity to explore the use of medical cannabis.

In some of these cases, modern science can now confirm certain anecdotal reports from medical cannabis users (e.g. from patients who use cannabis to alleviate gastroinstestinal diseases). In other cases, this research highlights completely new potential clinical uses, for example the use of cannabinoids to modify the progression of diabetes. In all cases, science has sufficiently demonstrated that cannabis is both safe and effective for certain patient populations.

The advances in the study of cannabis are promising and, as with any major medical breakthrough, we must overcome challenges and present some solutions. For example, microdosing is likely to become an ongoing trend that will continue into the future. Evidence shows that low doses of cannabinoids, specifically THC, can effectively combat stress, depression, anxiety, pain, and inflammation. In addition, small doses of cannabis can also promote productivity, concentration, relaxation, creativity, and a sense of well-being.

But some of the most exciting possibilities that could be developed have little to do with the plant itself. The active compounds found in marijuana can not only inspire scientists to develop a range of useful synthetic medicines, but can also lead them to a greater understanding of the role of the endocannabinoids (such as anandamide) produced by the human body.

Research has already revealed that cannabinoids influence numerous physiological processes and biochemical pathways, each of which represents a potential action space for new highly specific drugs. With the arrival of treatments designed to work with the endocannabinoid system itself, the medical use of marijuana should now fade as a topic of heated debate to finally become, once and for all, a significant page in the history of medicine.