In an attempt to deal with the proliferation of cannabis dispensaries, the City of Vancouver has released a policy to attempt to regulate these businesses. This is directly opposed to the Federal Government and Health Canada, who would prefer to just have them all shut down.

My interest is in the science of the policy. Here is their summary of risks:

Studies on marijuana use have linked its use to health harms such as impairment of memory (in adolescents) and psychomotor performance; schizophrenia; cancer of mouth, jaw, tongue and lung (in younger people); fetotoxicity; and leukemia in children



Leukemia? Where does that come from? This is not a side effect that is mentioned in the modern, extensive, if biased review from Dr. Volkow, The Adverse Health Effects of Marijuana.

The answer comes from the reference used to support the evidence in this section.

This risk section seems to be have summarized from the abstract from this article, The Human Toxicity of Marijuana, by Nahas and Latour :

These include: long-term impairment of memory in adolescents; prolonged impairment of psychomotor performance; a sixfold increase in the incidence of schizophrenia; cancer of mouth, jaw, tongue and lung in 19-30 year olds; fetotoxicity; and non-lymphoblastic leukemia in children of marijuana-smoking mothers.





The choice article is rather bizarre. This is a 23 year old article with an interesting history behind it.

In the early 90′s, Australia was considering liberalizing its’ cannabis laws. As part of their international drug war, the American government brought in Dr. Nahas, an anesthetist who played a big role in the Reagan era “Just Say No” campaign. This campaign has been said to have done as much for drug abuse as “Have a Nice Day!” did for clinical depression.

(Photo from New York Times)

Dr. Nahas made a number of public appearances warning about the dangers of cannabis, culminating in the publishing of his article in the Medical Journal of Australia. This was a paper so full of errors that it resulted in a scathing review article from two Australian pharmacologists. Dr. Nahas’ work was unbalanced enough to be referred to by the NEJM as “psychopharmacological McCarthyism that compels him to use half-truths,innuendo and unverifiable assertions.”

(Image from Amazon.com)

Columbia University eventually dissociated itself from Dr Nahas and his funding was cut off by the NIH in 1976. Despite this, he remained popular on the lecture circuit and his views were promoted by Readers Digest.

His assertion that marijuana causes leukemia in children was disproven in 2006, with better research showing no connection.

The Vancouver City Council has made a bold move in attempting to regulate dispensaries. They have vaulted beyond other regulatory agencies by including a section on the harm reduction aspects of cannabis, namely:

1. as a substitute for more harmful drugs (e.g. alcohol, tobacco, prescription opiates and some illegal drugs such as heroin or cocaine)

2. as a means to reduce the rates of opioid overdose deaths and opioid-related morbidity

3. to relieve withdrawal symptoms during detox and to increase retention rates during treatment

Cutting edge policy requires cutting edge science. Surely there are modern day experts living in Vancouver who could be consulted, rather than relying on advice from a long discredited counter-reformer