Does Cannabis Cure Cancer?


By Keith Mansur

Oregon Cannabis Connection

Orig Pub. Aug/Sep 2014 Issue

As the publisher of the Oregon Cannabis Connection I have had many opportunities in the past four or five years to review many claims about cannabis curing cancer. I have heard numerous people make claims that cannabis cures dozens of ailments, including the big “C”, but I have a skeptical mind, and need scientific proof of almost anything before I will believe it.

So, I set out on a little research project to see what all the hubbub is about. With a quick Google search, you can find all sorts of websites making “cannabis cures cancer” claims. There are videos, websites, blogs and more, many with convincing anecdotal stories of someone that was “cured” by using cannabis.

Many sites have posted articles making some remarkable claims which helps to encourage the onslaught of misinformation. When you go through the studies and read them, the claims of a cancer cure just don’t hold up to scrutiny.

The most famous story of cannabis curing cancer is the Rick Simpson Story. Simpson, a Canadian, has claimed for years that his Rick Simpson Oil, or RSO, cured his malignant melanoma, an often fatal type of skin cancer. The oil he makes is a whole plant cannabis extract made using naphtha.

Simpson says he cured the cancer by rubbing the oil on his cancerous spots. Eventually his cancer apparently disappeared. He has developed a website to promote his message in a film called “Run From The Cure” at Of course, he is also selling his book for $9.99 plus shipping!

Unfortunately, Simpson’s story is not backed by evidence. It is anecdotal and that is all. The fact that he is selling a book and promoting his own name requires skepticism, at least. I may be making some enemies here, but the Rick Simpson Story is just that, a story.

Here are some bold headlines recently, thanks to Sanjay Gupta’s references in his CNN special last summer “Weed”, where he referenced some of the more promising studies, though never claiming cannabis was a cure:

Headline from Cannabis CURES cancer. OK, so now what? I need help… 20 Medical Studies That Prove Cannabis Can Cure Cancer Cannabis can CURE CANCER – cheaply and without getting you high

Headline from Harvard Study Says Marijuana Cures Cancer

That last headline is from a study that was completed by the Department of Medicine at Beth Israel Deaconess Medical Center and Harvard Medical School back in 2007 on mice. The study was remarkable, to be sure. Very promising results showing cannabis as a possible treatment for lung cancer. The headline says that marijuana cures cancer…YIPPEE!

But, you should not believe everything you read. This is what the study’s abstract actually said:

“Our study suggests that cannabinoids like THC should be explored as novel therapeutic molecules in controlling the growth and metastasis of certain cancers.”

And this, directly from one of the researchers, Anju Preet, Ph.D.,

“THC offers some promise, but we have a long way to go before we know what its potential is.”

These are big claims, and unfortunately the studies that are frequently referenced do not back them up. Although a large number of studies are now showing cannabis is effective in treating some types of cancer, just a handful of studies have led to many of the claims.

In one frequently cited report, a study was done using cannabis to battle brain tumors. Published in the JCI (or Journal of Clinical Investigation) in 2009, and entitled Cannabinoid action induces autophagy-mediated cell death through stimulation of ER stress in human glioma cells , the report was very positive.

The popular website reported it this way:

“Laboratory tests conducted in 2008 by a team of scientists formed as a joint research effort between Spain, France and Italy, and published in The Journal Of Clinical Investigation, showed that the active ingredient in marijuana, known as tetrahydrocannabinol or THC, can function as a cure for brain cancer by inducing human glioma cell death through stimulation of autophagy.”

But, the report actually said this:

“These findings describe a mechanism by which THC can promote the autophagic death of human and mouse cancer cells and provide evidence that cannabinoid administration may be an effective therapeutic strategy for targeting human cancers.”

Tommy Chong has even made the cancer cure claim. In 2012 Tommy Chomng, of the famed “Cheech and Chong” comedy duo, told a captivated marijuana nation that he had stage 1 prostate cancer. Although he had been abstaining from marijuana for a few years, he decided he would treat his cancer with cannabis, among other things.

On May 6, 2013 Chong tweeted “That’s right, I kicked cancer’s ass! So the magic plant does cure cancer with the right diet and supplements.”

Now, I am no expert in scientific studies, but I know when a claim is blown out of proportion. In the case of cannabis curing cancer, the inaccurate reporting is plentiful across the internet. When so many people get their news from obscure, untrustworthy websites, or base their beliefs on claims by celebrities, these types of falsehoods take on a reality of their own.

Before everyone gets their joints in a wad, I do believe cannabis could help if you have cancer. There is serious potential for cannabis in medicine.

Studies show that cannabis has, in some cases, reduced tumor growth, prolonged life expectancy, improved quality of life, and more. It is a natural plant and shows few side effects in most cases. It has helped on breast tumors, lung tumors, brain tumors and other cancers.

But, studies have also shown cannabis to cause tumor growth in some instances. It has side effects, though minor, including an unpleasant psychoactive effect on many people. The cannabinoids in the plant and endocannabinoids in our body, their interactions and effects, are not yet well understood.

Kat Arney of Cancer Research UK explains the science behind cannabis and cancer in her post on science blog, Cannabis, cannabinoids and cancer – the evidence so far. In the expose, she breaks down the science, the claims, and the evidence, and the truth about cannabis research for cancer treatment. She found the curative claims are unwarranted.

Even though there are hundreds of studies out there showing promising results, Arney explains the implications claiming cannabis is a cure, writing, “Claims that this body of preclinical research is solid “proof” that cannabis or cannabinoids can cure cancer is highly misleading to patients and their families, and builds a false picture of the state of progress in this area.”

Cannabis could save the world, but it wont happen using hack science and anecdotal stories. It will happen when effective studies are done on a large scale by the best scientists in the world with the best cannabis available. Until we have freed the plant from bondage and disgrace and can study it with vigor and proper funding and materials, our knowledge of this magnificent plant will continue to be meager and anecdotal.

Keith Mansur

Keith Mansur is the founder, publisher, and editor of Oregon Cannabis Connection newspaper. The print publication has been serving Oregon since 2010. He has been a Oregon medical marijuana patient, grower, and caregiver since 2006. Find him on Facebook or email him at

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2 thoughts on “Does Cannabis Cure Cancer?

  • 01/12/2017 at 4:59 pm

    These big companies only care about money and profits they could get.
    They don’t care what will be the effect of their greediness to all the
    people and their surroundings what really causes cancer are all this
    preserve food they are making, how can a preserve food last for three
    months, i have been buying preserved food for my kids as a single father
    because i do not have enough time for my kids due to my job, then
    suddenly my first daughter feel sick and i quickly run a check on her
    and discovered she was diagnosed of cancer, as a Doctor i looked for
    cure but couldn’t find any my daughter started taking drugs like her
    whole life depends on it, it wasn’t working the cancer was still
    spreading i searched more on the internet i found a testimony on how it
    cured someone then .i copied the email immediately the i wrote to this very,
    in an hour i got a feedback asking me few questions, and enlightened me
    on how to get the oil in the next 48hours, i placed my order and in the
    next 48hours the medication oil got to me in Nairobi Kenya immediately
    my daughter started using the oil, it been two months now, since my
    daughter has been using the medication oil and the cancerous problems
    are gone this very fact was clarified by me and other doctors
    i put
    up this piece of testimony for the sake of those once who need this oil
    to please don’t die in silence their is a cure for your cancer today and get the oil.

  • 01/12/2017 at 5:47 pm

    I appreciate your comments, but its still anecdotal. One-off examples do not make studies. I cannot recommend anyone get your oil you recommend or should they call it “Rick Simpson Oil” or RSO, he did not discover it and has asked that people stop calling it that.

    What you say may be true, but until there is a big study done properly, it will not be accepted science. Cannabis activists can scream and shout all they want, but the medical profession works in science, not anecdotal examples.

    And, I deleted your email links, not allowed.

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