Latest cannabis research: five new studies to know about

In recent weeks, promising research has been published on the potential of cannabis as a tool for sleep, muscle recovery, multiple sclerosis (MS) and inflammatory bowel disease (IBD).

With a record number of research papers published on cannabis and its therapeutic potential in 2022, it can be hard to keep up. While regulators call for more scientific evidence, studies are ongoing across the globe investigating its role in managing the symptoms of a wide range of conditions.

A number of studies – including several randomised control trials (RCTs) widely thought to be the ‘gold standard’ of science – have been published lately, providing new insights into its effects in MS, IBD and insomnia. While CBD also shows promise as a tool for promoting muscle recovery and improving memory in CUD.

We break five new studies down into what you need to know.

• Medicinal cannabis improves sleep in adults with insomnia

A double-blind randomised placebo controlled study found that medicinal cannabis oil improved both time and quality of sleep in a group of patients with self-reported insomnia.

A total of 29 participants took part and were randomly allocated to receive either a placebo or active oil containing 10 mg/ml tetrahydrocannabinol (THC) and 15 mg/ml cannabidiol (CBD) over a two-week period.

According to the paper, participants kept a daily diary to assess tolerability, and effectiveness was measured by saliva midnight melatonin levels, validated questionnaires, and the Fitbit sleep tracker. 

The cannabis oil was found to improve both time and quality of sleep. Light sleep increased by 21 minutes per night compared to placebo, and the quality of sleep improved overall by up to 80% in the active group.

The authors conclude that the oil was ‘well tolerated’ with 60% of participants no longer classified as clinical insomniacs by the end of the trial period. 

Read more about the study here.

• How CBD could promote muscle recovery 

CBD has gained increasing popularity among athletes since it has no longer been considered a prohibited substance by the World Anti-Doping Agency. 

A narrative review of existing research found that CBD has the ‘prospective to become an adequate supplement that may improve muscle recovery’. In animal studies, CBD was shown to be effective in increasing the expression of metabolic regulators in muscle of obese mice, while CBD treatment in rodents reduced muscle inflammation following exercise in a model of muscle dystrophy.

In humans, there were ‘some indications’ that CBD supplementation improved muscle recovery and performance, although doses were ‘highly variable’, the authors say. Read more here.

• CBD may improve cognition in cannabis use disorder (CUD)

CUD is defined as the continued use of cannabis despite adverse consequences, causing clinically significant impairments or distress, and is estimated to affect up to 13 million people around the world.

In a randomised clinical trial, researchers assessed whether four weeks of treatment with CBD impacted cognitive function in people with CUD. Seventy participants were randomly assigned either a placebo, 400 mg or 800 mg of CBD. The researchers concluded that while CBD did not influence delayed verbal memory or have broad cognitive effects, 800 mg of daily treatment may ‘improve working memory manipulation’.

Read more about this study here. 

• The effect of medical cannabis in inflammatory bowel disease (IBD)

Real-world data taken from the UK Medical Cannabis Registry provides some insight into the effect of cannabis-based medicinal products (CBMPs) in IBD patients. 

Seventy-six patients were included in the case series, with outcomes assessed at one month and three months, via a number of validated questionnaires, including the Short Inflammatory Bowel Disease Questionnaire (SIBDQ), Generalised Anxiety Disorder-7 (GAD-7), Single-Item Sleep Quality Scale (SQS), and EQ-5D-5L Index score.

The average baseline SIBDQ score improved at one month and three months, while quality of life, anxiety and sleep scores also improved at the three-month mark. Just over 20% of patients reported adverse events, with the majority being mild to moderate in severity. 

The authors concluded that prior cannabis consumers ‘reported greater improvement compared to cannabis-naïve individuals’.

Read more here. 

• Multiple sclerosis (MS) and use of medical cannabis 

A retrospective review of the medical records of 141 patients with MS aimed to evaluate the effect of medical cannabis on their symptoms. 

According to the paper, patients experienced ‘extensive MS symptom improvement’ after the initiation of cannabis treatment, with alleviation of pain (72%) and spasticity (48%) and improvement in sleep (40%) the most common.

There was also a ‘significant reduction’ in opioid use among patients. 

The authors concluded: “In many patients with MS, MC was well tolerated, eased pain and spasticity, improved sleep and other symptoms, and reduced use of concomitant opioid analgesics. Prospective studies are needed to further investigate the role of MC in the treatment of patients with MS.”

Read more on medical cannabis and MS here. 

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