Cannabis Cures Cancer?

Canadian Hemp activist Rick Simpson has been fighting for several years for the legalization of marijuana, THC-heavy hemp, and has been attempting to promote some very aggressive claims as to the curative effects of THC in the form of hemp oil. In November, Mr. Simpson’s residence in Amherst, Nova Scotia was raided by the RCMP and he has since been in exile in Europe after attending a cannabis conference in Amsterdam. Simpson’s website promotes the use of hemp oil, derived from the buds of cannabis and not the seeds, as the cure for “almost every disease.” The type of hyperbole on Simpson’s website and the documentary Tears of the Phoenix deserves a skeptical eye and I will attempt to apply it here.

The Endocannabinoid System

The discovery of the system of receptors in the body that respond to THC, one of the active ingredients in the hemp plant, and other so called “cannabinoids” was made in the early 1990′s. The two receptors, the CB1, which is found in the central nervous system, and the CB2, associated with the immune system, have since been heavily studied. The Wikipedia article on the health effects of cannabis lays out most of the accepted information about these receptors and is a good resource. CB1 receptors have been around for a very long time, having been identified in many mammals, fish, birds, and many invertebrates, with CB2 receptors appearing only in mammals thus far.

The molecules that attach to these receptors, called ligands, have been identified in the body as well. The myriad effects of anandamide and 2-arachidonoyl are still being teased out in basic research. Suffice it to say that the endocannabinoid system is very complex, the CB1 receptors tying into appetite and memory and the CB2 identified as immune system regulators.

“A cure for almost every disease known to man”

Some of the many cures and therapeutic effects espoused on Simpson’s website include:

Skin Conditions
Burns, Ulcers, Warts and Moles
Migraine Headaches
Weight Regulation
“Rejuvenates Vital Organs”

…and many others. What rings all of the skeptical bells is the cure-all claims that many THC advocates are making. Given the the many active biological agents found in cannabis, and the hundreds of animal and cell culture studies that have been done (PMed listed over 12000 articles with the search term ‘cannabis’) it is certainly plausible that cannabis has positive health effects, but the most glaring indication of fantastical thinking on Simpson’s website is the over-reliance on anecdotal information.

What Are They Smoking?

As with most herbal remedies, testimonials abound, but is there real evidence to support the effects that Simpson and others are claiming? Cochrane has 3 reviews concerning cannabis, three of which are complete and show no evidence to support or refute cannabis in the treatment of Schizophrenia, Tourette’s syndrome or Dementia. Cochrane is still studying cannabis for the treatment of nausea in cancer and in symptom relief in HIV/AIDS patients, so conclusions have not been drawn.

Human trials are still sparse, but a few are very promising. Pain relief is a active area of research with a recent paper showing good results for cancer patients. Many of the diseases mentioned above are concerned with inflammatory responses in the body, as CB2 receptors act to regulate inflammation, perhaps they are great targets for study. The big claim is the one about cancer. There are a few articles about the potential of cannabinoids in the treatment of cancer, but most them concluded that more research was needed. The effects of cannabinoids on programed cell death are promising, but I could find no studies linking the ingestion of hemp oil and the shrinkage or disappearance of tumors: the evidence is all anecdotal so far.

What is worse, the cardiovascular claims made by Simpson and his followers may run counter to current evidence. Rimonabant, a CB1 antagonist, meaning it blocks the CB1 receptor from accepting stimulation, as been shown in numerous trials to improve insulin sensitivity in diabetes patients and is tied to improvement in the cardiovascular system. This tells me that the claim that cannabis, containing cannabinoids that will stimulate the CB1 system, may be having the opposite effect than claimed. The following is a quote from a study on endogenous cannabinoids and its effect in metabolic syndrome:

“Pathological overactivation of the endocannabinoid system (ECS) in various forms of shock and heart failure may contribute to the underlying pathology and cardiodepressive state by the activation of the cardiovascular CB1 receptors. Furthermore, tonic activation of CB1 receptors by endocannabinoids has also been implicated in the development of various cardiovascular risk factors in obesity/metabolic syndrome and diabetes, such as plasma lipid alterations, abdominal obesity, hepatic steatosis, inflammation, and insulin and leptin resistance. ” [ref]

To be fair, there is an indication that cannabinoids can be helpful, and further study in human trials should be encouraged. According to one drug company, Cannabis Science,
“…cannabis has been recommended as a treatment for many diseases and ailments in anecdotal reports and scientific literature. Some of these ailments include: Pain, arthritic conditions, migraine headaches, anxiety, epileptic seizures, insomnia, loss of appetite, GERD (chronic heartburn), nausea, glaucoma, AIDS wasting syndrome, depression, bipolar disorder (particularly depression-manic-normal), multiple sclerosis, menstrual cramps, Parkinson’s, trigeminal neuralgia (tic douloureux), high blood pressure, irritable bowel syndrome, and bladder incontinence.”

There is much evidence for this, though Cannabis Science has no links to any of its research. The standard of care for cannabis for any cure cannot, as yet, be established.

The Veneer of Pseudoscience and Conspiracy

The two main fallacies that Simpson employs are the natural fallacy and the argument of a conspiracy by Big Pharma to withhold the cure for cancer and other ailments. Selling cannabis as the all-natural cure-all is a no-brainer because it is a standard tune in the herbal industry’s bag. Of course, the be fair, Rick Simpson is not selling anything – he is just disseminating information on the wonders of cannabis and some very simple techniques of distilling hemp oil from the hemp, provided that you can get a pound or two of it.

The dangers inherent in this seem only to be the illegality of growing it, without a license, and the flammable gases produced by boiling off the solvent, like naptha or isopropyl alcohol. Both of these dangers are not inconsiderable. Cannabis is generally accepted as a very safe drug to take, and ingesting it without smoking is desirable, considering the recent evidence of DNA changes and the high amount of ammonia and other toxic inhalants produced from smoking it.

The Big Pharma fallacy seems largely baseless, given the intense scrutiny given to cannabinoids by researchers the world over. This claim is made using very sparse circumstantial evidence: “they used to sell them in the 19th century, but because you can’t patent a plant they can’t make money — therefore they will not develop this obvious cure”. Given the ability of a pharmaceutical company to patent any medicines derived from the plant, when it is purified, regulated, shown to be efficacious and monitored properly, there does not seem to be any disincentive to develop cancer therapies, especially in light of recent Spanish endeavours.

Political Difficulties

What is obvious is that certain societal misgivings about the use and abuse of psychotropic drugs is getting in the way of research, development and proper public health policy. The current government’s ignorance of the positive findings at the Safe-injection Site in Vancouver, the probable prosecution of Rick Simpson should he return to Canada, and the continued illegality of marijuana despite public pressure to decriminalize it, all are hot-potatoes, politically, and may be impeding the availability of funding to properly study cannabis. In the mean time, advocates like Rick Simpson are not helping matters by making wild claims using anecdotal evidence. Simpson and his followers, which appear to be many, do have something: there is a lot of very interesting research. However we need science to help us navigate the hyperbole, and making claims for all-powerful wonder cures only ensures greater confusion in the matter.

24 Responses to “Cannabis Cures Cancer?”

  1. Dave says:

    This is a really misleading article, there are a lot of studies that indicate that cannabinoids help eliminate a variety of cancers and kill cancer cells. Just because the articles that these studies are described in typically end with the phrase ‘more research is needed’, probably for political reasons more so than medical ones, doesn’t invalidate the findings. The 1974 government study that was supressed for example in tumors were enduced in mice and then THC was injected into the area that the tumors were and they shrunk significantly. More disinformation sold as ‘skepticism’.

    • Kim Hebert says:

      Did you even read what Michael wrote? It’s reasonable to analyze hyperbole so that marijuana can be studied and used objectively for medical purposes, if validated.

    • Jules says:

      there are many studies showing certain plant compounds to have similar properties, , like capsaicin in hot peppers doing the same thing. just type capsaicin and cancer into pubmed search engine, you will find many findings that capsaicin shrinks or eliminates tumors as well. also noteworthy are sulphuranes in cruciferous vegetables, allicin in garlic and onions, spices like turmeric and saffron, recently it was found there are even anticancer cembranoids in green tobacco leaves and flowers. why do you think they recommend you eat fruits and vegetables to reduce your risk of cancer? it doesn’t mean those compounds or plants will cure cancer.

  2. Ronnie Smith says:

    The stories are far more than anectdotal. I have cured over 150 people of terminal cancer hundreds of people of diabetes and quite a few glaucoma victims.
    I have made incredible advances with a parkinsons patient. I have been compiling video testimonies from my patients and placing them on youtube.

    I am now running for sheriff so that I can spread the cure with impunity…

    • Kim Hebert says:

      Have any evidence to back up those claims? Personal testimonials are among the lowest forms of evidence. What scientific trials support your claim that you personally have cured 150 people of terminal cancer, diabetes, etc?

    • CR says:

      I completely thought you were a troll until I saw your youtube vids… I guess that means you are delusional.

      Fantastic claims require fantastic evidence, and I would be willing to bet money that in all of your “incredible advances” you’ve never taken the time to do any sort of properly blinded study to confirm your beliefs. In fact, I would also be comfortable in betting that the vast majority of your claim is fabrication.

      Also, Ronnie, if you want to help sick people why the hell are you running for Sheriff?

  3. G Washington says:

    Hey Kim,

    The body of scientifically replicatable evidence is OVERWHELMING.

    And, if I may, it is absurd to think that there should be another body of scientifically replicatable trials in support of actual cancer patients being cured when it is ILLEGAL for most residents of USA Inc to even possess cannabis….thanks to the Crime Against Humanity, AKA Prohibition.

    Do some research, apply some logic, then get back to us….

    • Erik Davis says:

      A few questions:

      1) Can you provide some pointers to this OVERWHELMING evidence?

      2) How did the evidence become so OVERWHELMING when the ILLEGALity of cannabis makes it so difficult to do a trial?

      3) Are there no research facilities in California, or any other state with medicinal marijuana laws? Or any other country?

      4) You realize that calling prohibition a crime against humanity belittles actual crimes against humanity like genocide, enslavement, apartheid, torture, rape, and forced sterilization, right?

      Put the bong down, apply some sobriety, then get back to us…

  4. Aaron says:

    If this stuff really cures cancer, “crime against humanity” would be an understatement.

    Your flippant and naive attitude is really disconcerting. If this stuff is claimed by so many to cure cancer, the least we can do is research the claims urgently and vigorously; but that is unlikely to happen until current legislation changes.

    It may interest you to know that pharmaceutical companies in the USA are now pursuing legislative changes that would make it legal for them to sell THC as a drug to the public. It will not be surprising to see a sudden surge of research funding for THC if these legislative changes come to pass; but until then, it is doubtful you will see any funding trickle onto the scene; mostly due to an ignorant public perception like your own. No company in their right mind would put funding toward an unprofitable technology, and no government would put funding toward a technology with no economic incentive unless there were incredible public pressure to do so. There is nothing shocking, profound, or conspiratory about these concepts. This is simple economics. Economic prosperity is the number one concern of almost anyone in society… until they come down with a terminal illness. It is just the simple nature of the insensitive, individualistic society we live in.

    • @ Aaron:

      My attitude was neither flippant nor naive, and I am sorry you took it that way. I argue through-out the piece that more research is necessary, though it seems that your pre-conceived notion that I was against research made you completely ignore the last paragraph where I summarize the current obstacles to properly researching the drug – research that I whole-heartily support.

      It appears that you did not finish reading the article past even the 1/2 way point either, as your economic argument does not hold water at all – there are several companies pursuing patents on medicines using THC and other cannabinoids – I am arguing for rigorous scientific research, not the “cure-all” silliness that is getting in the way of good research and will continue to obscure the path towards the proper development of medicines that actually make people better.

  5. Gary says:

    The best sense I’ve jeard so far anywhere on the net regarding the Rick Simpson story.

    Would be great if you could sort the typos in this article! CD receptors should be CB receptors… lol, sorry for nitpicking.. otherwise, great job!

  6. Thanks Gary – change made – that was a stooopid one. Thanks for the kudo’s!

  7. john morton says:


  8. imd says:

    Another typo: amandamide should be anandamide.

  9. Greenman says:

    Delta9-Tetrahydrocannabinol inhibits epithelial growth factor-induced lung cancer cell migration in vitro as well as its growth and metastasis in vivo.

    • Jules says:

      Capsaicin sensitizes TRAIL-induced apoptosis through Sp1-mediated DR5 up-regulation: involvement of Ca(2+) influx.

      Capsaicin cures cancer!

      Also potatoes do as well.

      And broccoli!

      Inhibitory effects of Broccolini leaf flavonoids on human cancer cells.

      Garlic anyone? Because it cures your cancer!

      Allicin inhibits cell growth and induces apoptosis in U87MG human glioblastoma cells through an ERK-dependent pathway.

      Here is one I especially like:

      Biocatalytic and semisynthetic studies of the anticancer tobacco cembranoids.

      The head research of that study also has a patent for his discovery. Anticancer tobacco cembranoids United States Patent 7977384

      Who knows maybe he will sell the patent to a pharmaceutical company and they will develop a new drug to cure cancer. But wait! If the drug really does cure cancer than the pharmaceutical companies won’t be able to make anymore money off conventional treatments. Besides anyone could grow the plant and extract the compounds themselves.

      I am fairly confident that I could continue going through pubmed ad nauseum finding similar articles for every fruit or vegetable eaten by man. But it would be silly.

      • Ask any oncologist or cancer researcher and they will tell you that killing cells in a dish is entirely different than killing only cancer cells in a living human.

        Then, please read “The Emperor of all Maladies: A biographry of cancer” by Siddhartha Mukherjee for a comprehensive look at cancer research over the past 100 years.

        Next see this discussion at the NCI on drug discovery for cancer -

        They have tested over 400 000 different compounds from animal, vegetable, mineral and sources off of every shelf in the chem lab and not many make it past this process. Don’t fool yourself, curing cancer (actually a multitude of different proliferation diseases) is extremely difficult and complicated

        In the mean time, please see this comprehensive review of so-called “neutriceuticals” for cancer – its conclusions are no where near as hyperbolic as “food cures cancer!”

        “…the efficacy of most nutraceuticals has been tested only in preclinical conditions, either in vitro or in vivo. Whether beneficial effects will be seen in humans is largely unknown. To date, success has been limited to a few cancers and to a few molecules”

        This research is very important and exciting, and without going through the Gish-gallop of your post to analyse every study (something that I doubt you have done yourself) I will accept that they are finding out interested things. However, taking a compound from killing a dish of cells to shrinking tumours in humans if exceedingly difficult – made more so by hyperbolic expressions of hyped-up hope offered by you in this thread.

    • Jules says:

      Just to troll you some more:

      Glycoalkaloids and metabolites inhibit the growth of human colon (HT29) and liver (HepG2) cancer cells. (regarding solanaceous plants, like eggplant)


      Apple polysaccharides induce apoptosis in colorectal cancer cells.

      Carrots and Ginseng

      Differential effects of falcarinol and related aliphatic C(17)-polyacetylenes on intestinal cell proliferation.

      All damn day….


      Branched α-(1,4) glucans from Lentinula edodes (L10) in combination with radiation enhance cytotoxic effect on human lung adenocarcinoma through the Toll-like receptor 4 mediated induction of THP-1 differentiation/activation.

      Maple syrup

      Antioxidant activity, inhibition of nitric oxide overproduction, and in vitro antiproliferative effect of maple sap and syrup from Acer saccharum


      Cocoa-rich diet prevents azoxymethane-induced colonic preneoplastic lesions in rats by restraining oxidative stress and cell proliferation and inducing apoptosis.

      It’s getting late…

      Beans (soybean)

      A peptide fraction from germinated soybean protein down-regulates PTTG1 and TOP2A mRNA expression, inducing apoptosis in cervical cancer cells.

      wow. I wonder how many cures for cancer there are :/

  10. Jules says:

    I was being sarcastic Michael.

  11. Daniel says:

    Hi I am a cancer researcher, Just wanted to add some points here.

    Firstly, there are hundreds of studies to show cannabinoids can kill cancer cells. Coupled with the fact that we know cannabinoids are some of the safest drugs in our pharmacopeia, and are already prescribed for cancer side effects, we would think someone would want to start giving these to human patients (or record the survival results from patients who already do).

    I agree more research needs to be done, but in Humans! We do not need to elucidate mechanism and do animal testing on cannabis, we have thousands of years of safety, we know it is safe, all we need to know is it effective.

    On top of killing cancer cells, we know cannabinoids also treat all the major side effects of cancer.

    I wont look them up now, but there are studies (as well as massive anecdotal evidence) to prove that cannabis helps with:

    Anorexia (Cancer patients find food sickening and can’t eat, but after a joint it is much easier-not hard to realize this is true)
    Cachexia (Cannot gain weight despite eating lots)
    Lack Of Sleep

    Cancer patients currently are given up to 5 different drugs with terrible side effects (anti-emtics alone KILL thousands per year, while cannabis, often far more effective, has killed NONE).

    Instead, they can take a single drug to treat all the side effects and kill the tumor, while leaving healthy cells and organs unharmed. Chemo is notorious for damaging organs like the heart and brain irreparably.

    See this is where there is the divergence from “conventional” medicine. Cannabis Helps the body to Heal. It stimulates healthy cells to clear out necrotic tissues and repair the niche which the tumor has exploited.

    Since the endocannabinoid system regulates such diverse bodily functions, from appetite to mood and sleep, it can have such a holistic effect on the body. Something a simple synthetic drug can never achieve. Cannabis oil has a synergistic combination of hundreds of compounds, not only cannabinoids but also terpenes and terpenoids.

    Cannabis helps people do what they need to Heal themselves:

    Eat, Sleep, and Feel Better. There is no better drug.

    So Lets Compare:
    Can Kill Cancer cells, but also damages healthy cells
    Damages Immune system (needed to kill tumor and remove necrotic tissues)
    Inhibits ability to eat and keep food down
    Damages organs
    Damages the environment in its production

    Selectively kills tumor cells, leaving healthy cells unharmed.
    Stimulates would healing and immune system to fight cancer
    Leaves organs healthy or even heals them
    Heals the entire organism, mind, body and spirit as one
    Heals the Entire PLANET in its production, cleaning the soil and air as we grow it.

    We are never going to “cure” cancer with synthetic drugs, their production makes pollution causing cancer. The “cure” for cancer will come from stopping the source!

    lets not forget that the Hemp plant can also:
    Make Plastics
    Make Fuel
    Make Clothes
    Make Food
    Make Paper
    All Without damaging the environment and causing environmental harm.

    Reductionist Scientist like to put it all down to the cannabinoids as the medicinal natural product.

    The Entire Cannabis GENOME is the most medicinal natural product, not just for the healing of humanity, but the planet as a whole.

    That’s REAL Medicine. That’s Life.

    • Daniel says:

      Cannabis can replace the ineffective medicines which harm our bodies.

      Cannabis can replace the ineffective industrial practices which harm our planet.

      To be skeptical of this is to be ignorant of the facts, IMO.


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  • Michael Kruse

    Michael is an advanced-care paramedic in York Region, just north of Toronto, Ontario. A semi-retired theatrical lighting designer as well, he re-trained in 2005 as an EMT-PS at the University of Iowa and as an ACP at Durham College, and is currently working towards a B.Sc at the University of Toronto. Michael is a founder and the chair of the board of directors of Bad Science Watch. He is also the recipient of the first annual Barry Beyerstein Award for Skepticism. Follow Michael on twitter @anxiousmedic. Michael's musings are his own and do not necessarily represent those of his employer or Bad Science Watch.