by Françoise Makanda at The Dalla Lana School of Public Health, U of T
Are edibles better than vaping cannabis? Is vaping cannabis better than smoking marijuana? Even the experts don't know—yet.
Since the legalization of cannabis in Canada, researchers are very focused on these questions, as explored in a new commentary published in The Lancet Regional Health – Americas entitled “Cannabis clinical research in purgatory: Canadian researchers caught between an inflexible regulatory environment and a conflicted industry.”
“You need full documentation on each cannabis product and that's incredibly expensive,” says co-author Michael Chaiton, Associate Professor at The Dalla Lana School of Public Health (DLSPH), and Independent Scientist at the Institute for Mental Health Policy Research (IMHPR) at CAMH.
Cannabis companies were initially enthusiastic about participating in this model until costs and capacity became an issue, says Chaiton. “[The attitude was] why do we want to do this? It is just going to tell us that some things are more harmful than others when we just want to not worry about that.”
Researchers like Chaiton want the ability to research cannabis products to compare their safety. But there is no independent system to study cannabis and enact quality control without support from the cannabis company themselves.
“There is sort of a push within Health Canada to try and get this sorted out, but it's not going fast enough. I'm worried that it's not going to end up in the way that it should.”
In a recent study comparing the health outcomes of vaping versus smoking, DLSPH Research Associate Anasua Kundu, U of T’s Assistant Professor of Psychiatry and IMHPR Independent Scientist Sergio Rueda, and Assistant Professor in the Department of Pharmacology and Toxicology and IMHPR Independent Scientist Patricia Di Ciano concluded that there was no substantial evidence that would pit one over the other.
“The public health approach to cannabis, including Canada’s Lower-Risk Cannabis Use Guidelines , recommends vaping over smoking cannabis. Part of the reason for that is because we assume that smoking any organic product is going to have a negative impact,” says Chaiton.
“And that is probably true. But to be honest we don't know.”
Vaping creates micro fine particles in the lungs that could be equally damaging to organic smoking.
Chaiton and DLSPH Professor and IMHPR Senior Scientist Robert Schwartz are kicking off a study to examine, through CT scans, lung damage from cannabis, vaping or organic smoking of cannabis. Chaiton believes it is one of the first studies to examine vaping cannabis versus tobacco. It might help resolve some of the enduring questions they can’t seem to answer.
"Cannabis was legalized on the pharmaceutical model. That really led to some understatement of the potential harms. And right now, certainly, compared to cigarette smoking, it seems to have limited damage compared to cigarette smoking, but partly I think, because that few people really ingest enough to have this sort of obvious effect,” he says.
Further, cannabis ingestion comes in many forms. Chaiton has noticed an uptick in cannabis edibles use among older people.
Still, Chaiton argues that the bottleneck is with Health Canada. "If you wanted to do a trial with alcohol, you can. You buy things from the LCBO and you can give them to people. Same with tobacco. You can just, again, buy things from a store since it is a product on the market. And again, ethically you give them to people who are already using them. And you can do comparative tests. You can't for cannabis.”
Products are evolving rapidly within the industry. Observational studies are needed. Canada is poised to be a leader in cannabis research as it is one of the few countries that have legalized its use, says Chaiton.
He is asking for change.
"We shouldn't have to rely on the cannabis companies to be able to do research. These are products on the market for consumers that are being used in normal way by people in their daily life.”