Getty Images

Weed and woo: Separating facts from fiction on the health benefits of cannabis

As someone with a severe chronic illness, Hannah McGowan has a vested interest in getting to the bottom of what cannabis can and can’t do for her health. The reality, she discovers, is complicated.

Woo [colloq.]: Mystical, supernatural or pseudo-scientific beliefs not backed up by evidence.

I crave a well informed, science-based conversation on the matter of cannabis law reform in New Zealand. I yearn for satisfying data. My hackles rise when I see cannabis being promoted as a miracle cure for desperate people with incurable ailments. I require proof, not woo. I want to examine peer-reviewed, empirically-proven evidence from rigorously scrutinised studies. I need to know the truth.

I live with multiple health conditions including Crohn’s disease (IBD), sleep disorders and central sensitization, a nervous system condition associated with chronic pain. While I am in remission thanks to taking Remicade, originally developed as a chemotherapy drug, the side effects include a compromised immune system, extreme fatigue, muscle aches, joint pain, brain fog and nausea. Remicade is a high-risk biologic medication peppered with black box warnings including lymphoma, a particularly deadly, fast-moving form of cancer. For the last two years I have visited a medical day ward for IV treatments of Remicade which have stabilised the disease; it is likely that I will require this regimen for the rest of my life.

This treatment is not a pleasant thing to endure every eight weeks as I have ‘difficult’ veins and intense anxiety around hospitals, stemming from waking up during emergency bowel surgery when I was 16. My pain levels are unmanageable despite trying every pharmaceutical option available, a hit or miss affair that has come close to killing me. My medical notes state that my general prognosis is ‘poor’ and I find myself with very few choices remaining.

However, there is still one more choice that I have not been able to fully explore. There exists a treatment that can relieve pain, stimulate appetite and alleviate insomnia without the need for three different pharmaceutical medications with unpleasant side effects such as dependency, depression and gastrointestinal distress.

That treatment is cannabis. Cannabis is showing real promise in alleviating various forms of pain and is widely regarded as being helpful for those undergoing IV therapy and suffering IBD. So it’s not surprising that I want to find out as much as I can about its medicinal potential. Unfortunately, in New Zealand, cannabis remains an illegal substance. And so I am left with a complicated mini pharmacy of drugs to treat not only my conditions but also the side effects of the medications I have to take for them.

A typical conversation about cannabis on a Crohn’s support group page (supplied)

Cannabinoid research has been frustrated and complicated by cannabis prohibition, so outcomes have yielded mixed results. Many studies are too small to lead to definitive, verifiable conclusions; some studies focus on just one cannabis molecule, ignoring its interactions with the hundreds of others that make up a cannabis plant. Still, one thing the studies have clearly shown is that cannabis is a safer substance than tobacco, which causes 5,000 deaths a year in New Zealand, or alcohol, which is a factor in one in three family violence cases and around 800 deaths in 2007 alone.

While tobacco and alcohol have almost no medical uses, cannabis already has several FDA approved therapeutic applications, and evidence is mounting that it is useful for a range of medical issues including multiple sclerosis and chronic pain. The medicinal potential of cannabis is exciting, but we need to not get ahead of ourselves. As we look towards the 2020 cannabis referendum it’s vitally important that we consider both sides of the debate.

Concerned parties have the right to have their questions answered honestly. Some advocates of cannabis refuse to admit there could be any negative effects resulting from cannabis use, but a study published this year suggests that that excessive use of high potency cannabis may not be great for susceptible individuals’ mental health. The Christchurch Health and Development Study raised concerns that adolescent use may increase the likelihood of mental health disorders in the small percentage (10-15%) of cannabis users who partake in a “heavy and abusive way”.

Cannabis can become problematic when used excessively, causing a condition known as cannabis use disorder, a psychological or habitual dependence on cannabis, and cannabis induced psychosis, Both risks are being exacerbated by growers breeding cannabis plants that are unnaturally high in Tetrahydrocannabinol, or THC, the psychoactive compound that gives cannabis its ‘high’.

A 2012 U.S study found that the cannabis smoked today is an estimated seven times more potent than it was in the 1960s. Until the 1970s, the average THC content in cannabis plants ranged from 0.3% to 4% depending on the climate, soil, growing conditions and handling after harvest. In 2019, some heavily modified buds have a THC content of up to 34%. “THC levels may be up to 90% or more in some extractions,” writes Michael Pollan in his book The Botany Of Desire, referring to products that separate and isolate cannabis components. A recent study investigating the link between high levels of THC in cannabis and psychotic disorder observed that daily use of highly potent cannabis carried “the highest risk for psychotic disorder”.

The best way to ensure THC levels in cannabis are safe? Legalisation. Regulating cannabis allows greater control over potency levels, and encourages the growth of low THC strains which have less chance of accidental or intentional overuse and psychological harm. Regulating cannabis is especially beneficial to adolescents, who are most at risk from overly potent products. (Another benefit: teens use cannabis less in areas where it is legalised).

Abe Gray and Michael Mayell of the proposed Whakamana Cannabis Institute, Christchurch (supplied)

Abe Gray, a plant scientist with a masters in botany and Michael Mayell, the founder of Cookie Time, are the pair behind Whakamana, a Christchurch institute focused on cannabis research, development and education (the institute is still in the planning stages but the two hope to open sometime next year). Research, development and education are the most beautiful words I could ever hear in relation to cannabis, so I was keen to hear their perspective.

When asked why there’s such a lack of conclusive data around cannabis, Gray summed it all up in one word: prohibition. “We haven’t been able to study cannabis for 80 years because it’s been prohibited,” he said. “There’s a huge gap in our data and we’re only just starting to get the evidence together now. We need to build up a body of evidence. Case studies are helping to get us there, but without the lifting of current restrictions we won’t have the freedom to pursue the answers people are looking for.”

While Gray is Whakamana’s cannabis expert – he’s the curator of Dunedin’s Cannabis Museum and the company’s in-house science guy – Mayell is the business brain of the operation. The involvement of one of our most successful entrepreneurs in the project brings up an obvious fact: with our talent for innovation, New Zealand could become a world leader in what is already a multi billion dollar global industry. Both cannabis and hemp production has the potential to transform our country from a commodity-based economy still reliant on dairy, meat, and wood exports to one that’s truly ready to meet the challenges of the 21st century. It’s illogical to ignore what becoming cannabis-friendly as a nation could do to help our struggling economy.

Eighty years of prohibition has created a vast gap in vital scientific data; they’re lost years that must be made up as soon as possible if we want to move forward. Medical cannabis products have the potential to immensely improve the lives of countless people but without law reform our options for treatment will be limited and the chances of getting sucked in by charlatans remains high.

And here we come to the next pressing issue, woo: beneficial claims that aren’t backed up by evidence. I realised woo was sneaking into the conversation when a local cannabis advocate shared an online post by Amsterdam-based Mike Wise, who like me has long suffered from Crohn’s disease. So of course Wise’s post “How I Cured My Crohn’s Disease Using High THC Cannabis Oil” instantly had my attention.

Here’s what you need to know about Crohn’s disease, aka Inflammatory Bowel Disease (IBD): it is a painful, debilitating, incurable condition. Around 75% of people with Crohn’s disease will have at least one surgery related to the disease in their lifetime. While Crohn’s patients can experience periods of remission from their suffering, there are no cases of anyone, ever, being cured of the disease.

Mike Wise began treating his condition with a home-made cannabis extract known as ‘Rick Simpson Oil’ in 2016, following the recommended protocol and building up to higher doses. It was this oil, Wise claims, that “cured” his Crohn’s. He doesn’t reveal the results of any recent colonoscopies or his past/current CRP levels (objective markers of inflammation that correlate well with disease activity) to support his claims. He just states that his “symptoms have completely subsided since beginning this protocol, and have not returned” without providing any evidence.

Wise is continuing to take small amounts of his version of the “RSO Oil”, but mostly he just sells it, promoting it as a cure not only for Crohn’s but also for “brain tumors and cancers, Alzheimer’s, COPD, the list goes on and on.” And people are buying it, literally and figuratively. As Wise proudly states, “Since I began to make the oil for myself, I have also made it for over 1000 patients around the world, as well as educating hundreds of thousands on how to make it themselves”.

Taking high-THC oil for several months is incredibly unlikely to cure Crohn’s, but it will probably evoke some kind of reaction. THC can cause hallucinations, delusions and altered thinking, especially at higher doses. Since Crohn’s patients have higher rates of anxiety and depression than the general population, it is difficult to know if ingesting extremely strong THC oil is more likely to produce sensations that are pleasant or unsettling. Wise does hint that it’s powerful stuff and suggests starting out with “a rice grain size” of oil three times a day, but it would be far too easy to accidentally ingest more.

Wise is pitching woo using the language of a snake oil salesman, and those who share this kind of unscientific nonsense on their online networks are pitching it too. While Wise sells his unproven RSO Oil, he and his acolytes also promote making your own. This is incredibly risky. Attempting to make your own cannabis-based therapies will always be unpredictable since there is little to no data on the potency of the cannabis in circulation throughout New Zealand. Unless you have access to specialised testing equipment there is no way of knowing how strong the end product will be. Buying an unregulated medicinal cannabis product, or making your own, has a chance of being the right treatment for you, in terms of strain, dose and delivery method. But there’s also a very real risk that it could be far stronger than you can handle. Worst case scenario: it affects your psyche in ways that are unpredictable, and possibly permanent.

CBD oil (Getty Images)

THC is the active ingredient in cannabis that makes some users tired or anxious, and it poses the principal risk to mental health. So remove THC from your cannabis product and the problem is solved, right? Well, not quite. In late 2017, under enormous public pressure, New Zealand legalised Tilray CBD oil. CBD stands for cannabidiol, another well-known active ingredient in cannabis, and CBD oil – which does not contain THC – is primarily used to treat seizures, nerve pain, anxiety and dependency issues. However many people are convinced CBD oil is a cure-all – albeit a very pricey one at as much as $570 for 25 days of treatment. After having CBD oil enthusiastically recommended to me several times by people in medical cannabis circles, I started digging around for proof that it could ease my chronic pain conditions.

My digging unearthed an unpalatable fact: CBD oil is regarded as little better than a placebo by most specialists, including a pain medicine physician at The Burwood Pain Management Centre in Christchurch who consults with my GP. Sure, CBD is a safe, quality-tested placebo, but there’s no evidence that it can ease the suffering of people with chronic primary pain. In a letter to my GP, the Burwood physician explained his stance on CBD oil: “Although there is no significant evidence that CBD eases chronic primary pain, if a patient reports significant pain reduction on it, then pragmatically I am happy to support its use, despite the lack of evidence-based, as long as the therapeutic benefits well outweigh any adverse effects.”

“Thanks to the media-hype and hysteria around so-called ‘medicinal cannabinoids’, the placebo effect of CBD is likely to be turbo-charged,” he went on. “In other words, it is quite possible that (the patient) will obtain a marked analgesic effect on CBD, whether this is pharmacological or placebo is uncertain.” His position is backed by recent scientific studies showing that widespread claims that CBD oil can control pain are not based on substantial evidence. Still, I was offered a prescription for Tilray despite a complete lack of evidence that it could help my particular condition. The placebo effect is worth a lot of money.

The strongest scientific evidence we have for CBD oil’s medicinal effects is in the treatment of Dravet syndrome and Lennox-Gastaut syndrome, two rare, severe forms of epilepsy that develop during childhood. Yet even in these cases CBD products do not work as well as treatment with cannabis itself, according to Dr David Bearman, author of Cannabis Medicine: A Guide To The Practise of Cannabinoid Medicine

There’s a whole lot more to the composition of cannabis than CBD and THC, the most commonly known molecules – there’s at least 512 of them, including terpenoids, flavonoids and cannabinoids. Bearman is a firm believer that the whole plant needs to be utilised in medical applications. “FDA approved pharmaceuticals only contain synthetic THC, are more expensive than cannabis, do not work as well and have more side effects.”

Abe Gray of Whakamana agrees that CBD-only products are not terribly effective. “CBD on its own without any THC is the most ineffective form of medicinal cannabis but the most politically accepted, because it’s a single compound that can be easily synthesised and has no psychoactive components. When it comes to medicinal use you need the full spectrum of components to work effectively.”

Promoting CBD as a cure for everything (ie – woo) risks encouraging those who believe the hype but can’t afford the products’ high prices to look elsewhere. And since black market cannabis in New Zealand tends to be high in THC, ‘homemade’ CBD treatments probably will be too, especially if users are not allowed to source and grow their own CBD-rich strains. Legal, regulated cannabis dispensaries could help keep medicinal users safe from the dangerous side effects of woo.

Homegrown cannabis

Join us and help us hire new
political & climate reporters
Find Out More

It is vital to foster a culture where the public can be honest about cannabis use and this can only happen through changing our outdated laws. Due to ongoing stigma around cannabis, patients are unlikely to disclose their use to their medical professionals. When people no longer have to hold back relevant information for fear of judgement or criminal charges, more useful data can be gathered. Too many health care providers still don’t understand how cannabis is affecting their patients’ psychological state or how it may be interfering with prescribed medications.

Regulation, careful law reform and age restrictions will allow people to experiment with cannabis in an informed and cautious manner under specialist, green fairy or GP supervision. As with any substance, some may take their use to extreme levels, but punishing people who are struggling with mental health or dependency issues does not stop these problems from occurring. A health-based approach will always keep the public safer than a harsh, criminal response.

Criminalising the production and use of cannabis hasn’t worked for us as a people or as a country. Current policy allows synthetic drugs to thrive, causing enormous health and social harms. It is time for a compassionate, health-based and scientific approach. Cannabis shows tremendous potential for alleviating many conditions, including multiple sclerosis, chronic pain and chemotherapy relief; it’s even showing potential for delaying the onset and progression of Alzheimer’s disease.

New Zealand needs to apply appropriate, well thought out guidelines for personal use and say YES in the upcoming referendum. It is the best way to open the doors to ongoing scientific research, mitigate potential harm, protect Kiwis from snake oil woo-pushers and find the most effective ways to utilise cannabis for medicinal benefit.


The Spinoff’s science content is made possible thanks to the support of The MacDiarmid Institute for Advanced Materials and Nanotechnology, a national institute devoted to scientific research.


The Spinoff is made possible by the generous support of the following organisations.
Please help us by supporting them.