Ex Editor Rachel O’Neill examines the claim that cannabis cures cancer when in fact, the evidence is yet to be produced.

Having a parent that suffers from cancer is never a fun experience. Having a parents that suffers from cancer when you’ve a neuroscience degree only adds to the distress. Why am I being so specific you might ask? Well my mother suffers from Triple Negative Breast Cancer. She cannot be cured but is not yet terminal which is a weird limbo to find yourself in.

What’s even weirder is the strange advice that people have given her. One person suggested that she spend €15,000 to fly to Germany and have her bloods changed. Another suggested that turmeric would cure everything while someone else suggested that having cancer “wasn’t that bad”. Outrage aside, there is no science to back up any of these claims apart from the belief that more antioxidants is good for you.

So where does cannabis come into all of this? Essentially people have been claiming that cannabis cures cancer for a number of years via shaky science or anecdotal evidence. The most recent incidence of this was Blindboy Boatclub who while not promoting the belief himself, did share a story of a friend who seemed to shrink his cancerous tumours through a paste that was high in THC on his popular podcast. My mother has been offered everything from edibles to cannabis oil in a bid to ‘cure’ her cancer but what exactly is the evidence to back up the claim?  Essentially there isn’t much. Many studies involving cancer and cannabis carried out in the past were not randomised or controlled properly meaning the evidence cannot be declared valid.

However, there is some evidence that cannabinoids (the family cannabis comes from) can slow down the growth of some cancers. For example in 1975 it was shown that lung adenocarcinoma cancer growth was reduced by the oral administration of THC and other cannabinoids in animal models by Munson et al. It has also been shown that cannabinoids can slow the growth of prostate cancer cells as demonstrated by Sarfaraz et al in 2005. But can we say overall that cannabis cures cancer? Absolutely not.

In 2016 the Barnes Report was commissioned to investigate all the potential therapeutic effects of cannabis for the UK government. It outlined the conditions where there was good evidence that cannabis was having a significant effect and other conditions where there was moderate, weak and theoretical evidence of an effect. This report concluded that there was good evidence that medicinal cannabis had therapeutic benefit for the treatment of chronic pain, chemotherapy induced nausea and anxiety management. They also found moderate evidence for the treatment of sleep disorders and some symptoms of Parkinson’s Disease.

So we know what it has been documented to help, but what about cancer? Well according to the Barnes Report, the evidence just simply isn’t there;

‘At the present time there is a reasonable evidence base for the anticancer properties of cannabinoids but very limited evidence of actual efficacy in human populations. Further studies are needed before any recommendation can be made.’

They also say; ‘We have found that there is a theoretical basis, but so far no convincing evidence of efficacy; for the management role in cancer/tumour control.’

So essentially the theory is there but it cannot be backed up animal models or in human studies so far. That doesn’t mean it won’t be and it doesn’t mean that cannabis isn’t useful. For example, it’s an excellent anti-nausea treatment for people going through chemotherapy and that treatment should be encouraged as should more research.

If cannabis turns out to be the wonder cure for cancer, then I’ll be the first one to welcome it. But you cannot it say it cures cancer based on theories and anecdotal evidence. Cancer is a multi faced illness that affects so many of us and to say that cannabis will cure it and it’s being halted by ‘Big Pharma’ and the government doesn’t help anyone. It just adds to the stress and despair that many cancer sufferers and their families go through. I know you think that you’re helping but believe me when I say that you’re not. There’s enough false hope out there without adding to it.

That being said, if you’re offering me a joint for fun, I’ll totally take you up on it.


By Rachel O’Neill – Science Writer