CBD No Better Than Placebo For Cancer Symptoms: Are We Back at it Again?

A study that was published last month in the Journal of Clinical Oncology found that cannabidiol (CBD) is no better than placebo in relieving symptoms of end stage cancer. This was a double blind and placebo-controlled study that was conducted by  Mater Research in collaboration with the University of Queensland. Before we even dive into the details of the study, one generally wonders how one compound in cannabis offered at the same dosage is supposed to relieve a myriad of symptoms. That more or less sounds like machine gun medicine, something that the medical cannabis community has often picked issue with. 

Here are details of the study

The study involved 144 participants, all who were  receiving palliative treatment for advanced cancer. The participants received either pure CBD or placebo for a duration of 28 days. The researchers investigated the effects of CBD in relieving general distress, pain, anxiety, and depression. They also monitored adverse effects. 

All the parameters were observed and recorded at 14 days and at 28 days. The results showed no significant difference in symptom improvement in patients who received CBD compared to those who received placebo. Also, adverse effects reported were not related to either interventions (CBD or placebo).  A conclusion was made that “CBD may not add value in reducing symptoms for patients with advanced cancer beyond standard palliative care.” And it seemed that the researchers were not surprised by this finding. 

“The best way to describe the uptake of medicinal cannabis following its legalization was as a social phenomenon—everyone wanted it, but there was little evidence to guide its usage,” said the lead researcher Professor Hardy. 

Issue one: Dosage of CBD offered for Palliative Care

The participants were offered titrations of CBD oil or placebo from 50mg/day to 600mg/day. In comparison, CBD oil for epilepsy (Epidiolex) is offered at a starting dose of 5 mg/kg/day (350mg for a 70kg man) to 20 mg/kg/day (1,400mg for a 70kg man). This is not to say that the CBD dose offered was too low. A different study showed that a dose of 300mg/day of oral CBD was effective in treating chemotherapy-induced peripheral neuropathy.

However, one wonders whether higher doses of CBD could have worked better for some symptoms.

Would it not have been more effective to assess one condition at a time and rule out the potential of different doses of CBD isolate in offering relief? Or can you conclude from one study that CBD isolate is not effective in relieving “a myriad of symptoms” in advanced cancer? 

Here is the thing.

Surprisingly, 36% of the study participants opted to purchase the CBD treatment in spite of being aware of the results and even being convinced that they were part of the active (CBD) arm of the study. There are two possible explanations for this; general optimism in spite of lack of evidence (as cited by the researchers) or the participants actually experienced an improved sense of wellbeing.  Dr. Greenspoon, a well respected thought leader in medical cannabis has previously reported that “people almost exclusively talk about their quality of life getting better when using cannabis as compared to opiates.”

But dosage is even the smaller issue here. 

Issue two: CBD Isolate Versus Full Spectrum CBD

Cannabis is made up of hundreds of bioactive molecules, with CBD and THC being the most popular. These compounds act together synergistically to enhance the therapeutic benefits in what has been described as the entourage mechanism. For example, when it comes to managing pain or nausea and vomiting, studies have shown that a combination of THC and CBD is more effective than an isolate of each compound on its own. While it is believed that THC has stronger analgesic properties, CBD helps to offset some of the negative effects of THC. In addition, terpenes also play a key role in unleashing the true potential of medical cannabis. Therefore, when looking at a broad range of cancer symptoms, it would be unfair to overlook the benefits that are offered through the entourage mechanism. While CBD as an isolate may offer great relief for epilepsy, it may require additional compounds or substitutes to address other cancer symptoms. 

Is CBD Any Good For Cancer?

That's a hard question to answer from any one study. Some studies have demonstrated anti-tumor properties of CBD in some cancers but not others. When it comes to symptoms of advanced cancer, this is best looked at on a case-by-case basis. While it may be true that there might be an “over-optimism” about medical cannabis, there also could be some “over-pessimism” from a sector of the medical community. And as the saying goes, if all you have is a hammer, everything you see will look like a nail.