A recent article that appeared in major media outlets across Canada claimed that cannabis use killed 8,851 Canadians in 2014.
The figure supposedly came from a report prepared by the Canadian Institute for Substance Use Research (CISUR), with backing from the Canadian Centre on Substance Use and Addiction (CCSA).
The focus of the study was on the financial costs to society associated with use of various substances, but it included death tallies as well.
After the story was printed, I seem to have been the only person to notice and question the astounding claim of 8,851 cannabis deaths. Could this be true?
I tweeted to the CISUR, CCSA and some media outlets, questioning this absurd figure. Soon Nick Eaglund from the Vancouver Sun replied.
He checked and found that the original study only claimed 851 deaths. He figured the Canadian Press reporter must have made a ‘typo’ when writing the story.
Whoa, that’s not correct. Canadian Press added an extra 8,000 deaths to that stat. I’ll get to fixing what we published. Page 25 of the actual study: https://t.co/YI7BLHZTI0— Nick Eagland (@nickeagland) June 26, 2018
To its credit, Canadian Press corrected its online stories across the country within a day or so. However, it’s strange to me that not a single editor or newsroom in the country checked to verify the 8,851 cannabis-death total before reprinting it.
Wait a sec…how many deaths from cannabis?
Even an estimated 851 annual death total for cannabis seems like an extremely big number! The CISUR isn’t talking about cannabis overdose deaths, as we all know those equal to zero. It’s claiming these are deaths from lung cancer and car accidents.
After I pointed out how the media had messed up the story, the CISUR put out a statement to clarify the cannabis death number and how it was derived.
Let’s take a look at the CISUR’s claims. Does cannabis cause 851 deaths in Canada each year from lung cancer and car accidents?
Cannabis does not cause lung cancer
The CISUR got its roughly 638 yearly cannabis lung cancer death total by relying on a single 2013 study in Sweden, which claimed that heavy cannabis users had double the chance of getting lung cancer over a 40-year period.
The CISUR then just applied that figure against the total number of cannabis users in Canada, and decided there must be about 638 deaths from lung cancer caused by cannabis each year.
However, the Swedish study has been criticized and debunked by subsequent researchers because 91 percent of the cannabis users also used tobacco! The study ‘did not adjust or account for tobacco use during the 40 year follow up period’.
If you’re not accounting for the fact that everyone in your lung-cancer study is smoking tobacco, then your results are not going to be valid or useful.
The CISUR and CCSA know that the Swedish study is baloney, because the CCSA even debunked it in its own report on cannabis from 2016!
Meanwhile, a major meta-analysis of six studies done by the International Lung Cancer Consortium in 2015 concluded there was ‘no overall association between cannabis smoking and all lung cancer’ among people who did not also use tobacco.
The 2016 report from the CCSA on cannabis and smoking explains ‘efforts to establish a relationship between cannabis smoking and lung cancer, while also accounting for tobacco smoking, have yielded weak if not non-existent relationships’.
A 2017 book called The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research published by the prestigious National Academies Press, analyzed every study ever done on cannabis.
The chapter on cannabis and cancer discusses all the current research and concludes ‘the evidence suggests that smoking cannabis does not increase the risk for certain cancers (i.e., lung, head and neck).’
It’s clear that the CISUR’s claim that cannabis use causes over 600 lung cancer deaths in Canada each year is simply not based on the most current or most reliable research.
It cherry-picked one unreliable study to derive the biggest number for cannabis deaths that it could. According to the latest research from the International Lung Cancer Consortium and the National Academy of Sciences, the number of lung cancer deaths caused by cannabis use each year is probably zero.
Very few car deaths caused by cannabis use
The CISUR report also claims there’s about 213 deaths annually in Canada from car accidents caused by cannabis use. This is about three times higher than the most current research.
A study released last year estimated only 75 cannabis-related annual driving deaths in Canada. This study was done by the CCSA, but oddly was not considered by the CISUR/CCSA report.
When cannabis-linked driving deaths do occur, they usually result from extremely high levels of cannabis use, or from cannabis use in conjunction with other substances.
It’s important to note that even with the CISUR report so heavily biased toward claims of harm about cannabis, it still concludes that the deaths and costs of cannabis use are trivial compared to those caused by the use of alcohol and tobacco.
At the end of the day, the vast majority of substance-related harms are attributable to alcohol and tobacco, with alcohol being ahead of tobacco. Opioids are a distance third, and cannabis ranks even below that.— CISUR (@UVic_CISUR) June 27, 2018
Cannabis use prevents many deaths and saves lives
Not included in the CISUR report are the benefits of cannabis use. Turns out, there are plenty!
When it comes to ‘cannabis costs’ and ‘cannabis deaths’, we should keep in mind important research done recently by the chair of the biology department of Indiana University, Thomas M. Clark.
He released a detailed meta-analysis last year, which found that cannabis use substantially reduces premature death, because ‘cannabis use is associated with decreased rates of obesity, diabetes, mortality from traumatic brain injury, use of alcohol and prescription drugs, driving fatalities, and opioid overdose deaths.’
After sorting through thousands of studies, researchers concluded that cannabis use reduces annual premature deaths in the U.S. from diabetes, cancer, and traumatic brain injury by between 989 to 2,511 deaths for each one percent of the population using cannabis.
Altogether, Clark estimated that medical cannabis access prevents between 12,100 to 30,600 deaths across the U.S. each year.
This analysis also found that ‘prohibition is responsible for an estimated minimum of 6,100 to 9,000 deaths annually due to lack of access to medical marijuana’.
It concludes that cannabis prohibition actually causes many more deaths than this, because people use more harmful substances like alcohol when cannabis is not available.
The conclusion is very clear: ‘Cannabis use prevents thousands of premature deaths each year, and cannabis prohibition is revealed as a major cause of premature death.’
None of these life-saving benefits of cannabis use were included in the CISUR report when calculating the social and financial costs of cannabis.
The CISUR included the most extreme claims of harm, no matter how scientifically dubious, while excluding strong evidence of benefits. This makes the conclusions of the CISUR report very unfairly biased against cannabis.
A truly unbiased look at the costs and benefits of cannabis use in Canada would have to conclude that cannabis use prevents many thousands of deaths each year.
Further, it is actually cannabis prohibition that is creating harm and causing many thousands of premature deaths nationwide.
The evidence shows that many tens of thousands of Canadians have had their lives improved and their lifespans extended due to cannabis use. This includes both the direct medical benefits of cannabis, and the health benefits of cannabis substituting for the use of more harmful drugs like alcohol.
With prohibition coming to an end, hopefully more Canadians will begin to use cannabis, which means we will have a healthier and longer-lived society.
Thank you to Ian Mitchell, Matt Elrod, and Dan McDain for their great tweets and research, which I used in this article.
