The Health Benefits Of Medical Cannabis: What Does The Research Say?

Alternaleaf Team
Written by
Alternaleaf Team
Jul 18, 2023
Last updated:
May 2, 2024

In Australia, doctors can prescribe medical cannabis for more than 130 chronic conditions, including epilepsy, anxiety, fibromyalgia, multiple sclerosis and cancer pain. If you’ve been living with your condition for over three months and conventional treatments either provided no relief or caused unacceptable side effects, you may be eligible for cannabis care.

The potential health benefits of medical cannabis is an area of emerging research. While a lot of the early studies are promising – and anecdotal evidence from patients is undeniably strong – a lot more high quality research is required before we can talk definitively about how cannabis might treat many of the conditions it’s currently prescribed for.

How Does Medical Cannabis Work In The Body?

Before we consider how medical cannabis, and in particular CBD and THC, affect the body, it’s important to understand the role your endocannabinoid system plays.

The endocannabinoid system, first discovered in 1992, refers to a network of receptors in your body known as CB1 and CB2. CB1 receptors are mostly found in the central nervous system, while CB2 receptors are mostly found in your peripheral nervous system and immune cells. Endocannabinoids bind to these receptors, causing an increase in enzyme activity – which in turn can have various effects on cognitive on bodily functions.

CBD and THC are two of the more than 100 cannabinoids in the cannabis plant. These ‘phytocannabinoids’ are similar to your body’s own endocannabinoids, making them effective at binding to receptors to prompt certain changes.

Studies are usually focused around the two main cannabinoids of the cannabis plant: tetrahydrocannabinol (THC) and cannabidiol (CBD). THC is the compound that produces marijuana’s psychotropic effects (commonly known as a “high”), while CBD acts on different parts of the body to produce its therapeutic effects.

However, THC & CBD interact with your endocannabinoid system in different ways. For example, THC binds to CB1 receptors to produce a number of effects, including a psychotropic effect commonly known as a "high". Meanwhile, CBD predominantly binds to CB2 receptors and acts as a modulator, producing different therapeutic effects with no associated high.

Benefits Of Cannabis For Pain Relief

Chronic pain is the condition that medical cannabis is most frequently prescribed for in Australia. So, what do we know about its effectiveness?

A 2022 meta-analysis found that high THC products were associated with moderate levels of pain reduction, while more balanced products offered slight improvements. However, the authors also noted a higher rate of side-effects at high-THC concentrations and said that more research is needed.

Another 2018 review found that cannabis was most effective in controlling “neuropathic pain, allodynia, medication-rebound headache, and chronic noncancer pain”

A study on fibromyalgia – a condition that can cause chronic pain in many parts of the body – found positive results with CBD use. Of 890 CBD users, the majority reported that CBD provided slight to strong pain relief.

In a small study on chronic pain among elite athletes, patients were treated with topical CBD cream and asked to rate their pain before and after treatment. All patients found that they had less pain around the home, while 93% reported improved pain tolerance when socialising, working and during recreational activities. However, these results should be treated with caution as the study only had 14 participants.

Benefits For Anxiety & Depression

Anxiety is your body’s natural response to difficult or tense situations. People with anxiety disorders experience excess worry, fear or even terror during everyday scenarios. This can also be accompanied with physical symptoms such as fatigue, restlessness, impaired concentration and poor sleep. These symptoms may persist for six months or more.

Similarly, depression is a common Mental health concern that can cause low moods, lack of interest and pleasure, low energy, feelings of worthlessness/hopelessness and even suicidality.

Recently, the interest in plant medicine to assist in managing anxiety and depression has grown significantly across the globe. Recent reviews of current literature suggest that cannabis treatment may be beneficial for some sufferers, however more well designed research is required in this area.

It will be a while before we fully understand how medical cannabis affects anxiety and depression, but the research so far suggests that medical cannabis may be worth talking to your doctor about if you experience either condition and have not had success with other treatments.  

Benefits For Inflammation

The discovery of CB2 receptors in the immune cells is suggestive of the potential benefits of cannabis as an immune system regulator. This has caused wide-spread excitement for the potential applications of cannabis in inflammatory conditions such as arthritis, Crohn’s disease, psoriasis and even acne. While many patients report improvement in symptoms, there is little research in humans that explores this and further research is required.

Benefits For Cancer Symptoms

There’s currently no evidence that suggests medical cannabis could be used to treat cancer, but it may be useful in managing some of the symptoms. Cancer patients may experience pain, anxiety and nausea – symptoms that medical cannabis can potentially reduce.  

Studies generally support medical cannabis use to manage nausea and vomiting, particularly in patients who are undergoing chemotherapy and seeking relief from the side effects. In Australia, the TGA has assessed that medical cannabis could be beneficial in the prevention and management of nausea, but further research is required.

Speak with your doctor if you experience difficult cancer symptoms or unwanted side-effects from current cancer treatment – medical cannabis is one of several potential treatments.  

Benefits For Neurological Disorders

Medical cannabis may help manage the symptoms of neurological disorders such as multiple sclerosis (MS) and Parkinson’s disease.

MS is the most common neurological disease to affect young adults. With MS, the body's immune system mistakenly attacks and damages the protective fatty tissue that surrounds nerve fibers. This can cause a range of symptoms including tremors, anxiety, visual disturbances and dizziness. There is no cure for MS yet, but medical cannabis may help manage the symptoms.

One common symptom of MS is muscle spasticity, where the muscles stiffen, potentially causing pain or interfering with movement or speech. CBD may have benefits for pain and muscle spasticity associated with MS. Nabilone, a medicine containing a synthetic version of THC, may also be effective at treating muscle spasticity.

Sativex, a combination THC-CBD product, is one of only two cannabis medicines fully registered with the Therapeutic Goods Administration, and is indicated for the treatment of MS-related pain and spasticity.

Parkinson’s disease, a neurological disorder that can cause shaking, stiffness, and coordination difficulties may also benefit from medical cannabis. A study looked at CBD’s effects and how it may improve sleep and quality of life in those experiencing Parkinson’s disease. The study was optimistic about medical cannabis’s role in treating Parkinson's, but emphasised that more studies are needed.

If you struggle with a condition such as MS or Parkinson’s disease, you may be eligible for alternative therapies such as medical cannabis to supplement your existing treatment.

Benefits For Epilepsy

Epilepsy is a chronic neurological condition that causes seizures. Epilepsy is the most common neurological disorder, and has many different types.

Medical cannabis is sometimes prescribed alongside other medications to help manage symptoms of epilepsy. CBD may have anticonvulsant properties, and CBD products such as Epidyolex are TGA approved for treating seizures brought on by rare forms of childhood epilepsy such as Lennox-Gastaut syndrome and Dravet syndrome.

This study on Lennox-Gastaut syndrome found that, compared to a placebo, CBD may have reduced seizures, with some mild side effects such as drowsiness, decreased appetite and diarrhoea. Another study on Lennox-Gastaut syndrome showed similar potentially positive results with CBD for treatment-resistant patients.

The evidence for treating childhood epilepsy with medical cannabis is clearer than with adults, but there is evidence for both.

Benefits For Sleep Disorders & Insomnia

Insomnia is a chronic condition that affects up to 15% of the population. Insomnia is characterised by experiencing difficulties falling or remaining asleep at least 3 nights per week for over 3 months. This has the potential to negatively impact overall health and productivity outcomes for those suffering.

Anecdotal reports of Cannabis improving sleep have been around for generations. So, what does the science say? A recent review suggested cannabis-based products demonstrated benefit in patients whose sleep is disturbed by pain and showed no difference between patients that used THC or CBD.

Recent research suggests that CBD can have a sedating effect, increase sleep duration and reduce the frequency of waking for some patients. However further research is needed to better understand this correlation.

A recent randomised, crossover trial on medical cannabis for insomnia looked at the effects of a new cannabinoid formulation that included THC, CBD and a minor cannabinoid known as CBN. The study’s participants reported an improvement in time taken to fall asleep, time spent asleep and feelings of being more refreshed and rested when waking.

Cannabis’s role in sleep isn’t well understood, but there is some evidence to suggest CBD may help if you experience insomnia. THC products may also have some effect on sleep architecture and dreams, but more studies are needed to understand this.

Could Medical Cannabis Benefit You?

Medical cannabis may help manage several conditions, such as anxiety, chronic pain and epilepsy. Cannabis’s role in managing conditions such as cancer, inflammation, insomnia and depression is somewhat promising, but needs more research. Whether medical cannabis will benefit you is something to discuss with your doctor.

If your condition has lasted more than three months and traditional treatments haven’t helped, you may want to book a consultation with your local GP or a medical cannabis clinic and discuss alternative treatments.

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