Researchers from U of T, affiliated hospitals form research consortium to study risks and benefits of cannabis

A new research and education partnership involving researchers at the University of Toronto and its affiliated hospitals will examine the potential health risks and benefits of cannabis and its compounds at a time when medical and recreational use is growing.

The Toronto Cannabis and Cannabinoid Research Consortium (TC3) was launched Thursday at a conference of researchers, government officials, policy-makers and industry representatives. TC3 combines the research muscle of the university with a dozen academic hospitals.

“There is a huge research engine at U of T,” said Ruth Ross, a professor and chair of the Faculty of Medicine’s pharmacology and toxicology department and a member of the TC3 steering committee.

More than 50 principal investigators are already members of TC3, which is focused on how cannabis and cannabinoids work, clinical research and public health.

“We’re hoping the consortium will spark multi-level collaboration across these three pillars, and we’ll get information into the hands of the public, government and health officials as quickly as possible,” Ross told Thursday’s Cannabis Innovation Summit.

Medical marijuana has been legal in Canada for almost 20 years, and recreational cannabis since October. Edible cannabis products will become legal in the fall  and there is also a whole new area of exposure emerging around cannabidiol (CBD).

The summit heard that research on both the potential benefits and risks is lagging.

Adding to the challenge is the fact 140 different cannabinoid compounds have so far been identified in cannabis.

“Cannabis is not a single substance, and if you take any of the literature that is published on cannabis, I can invalidate 99 per cent of it simply because nobody identifies the substances properly,” said Lakshmi Kotra, a U of T professor at the Leslie Dan Faculty of Pharmacy and a TC3 steering committee member.

Kotra shared an anecdote about collecting 186 samples of medical cannabis from patients and testing them all in his lab. “No two samples were the same.”

One of the panels at Thursday’s summit looked at the societal issues of cannabis (photo by Jim Oldfield)

The summit heard a range of concerns from researchers about potential harms from cannabis use, including the impact of second-hand smoke, the effects on pregnant women and their fetuses, and altered brain chemistry in young adults and adolescents.

But investigators indicated they were also inspired by the tantalizing hints of potential benefits from cannabis in all its variations.

The list of potential benefits with at least some scientific validation includes chronic pain, epilepsy, MS, depression, anxiety, chemo-related nausea, autism, PTSD, Tourette syndrome and glaucoma, as well as some aspects of Alzheimer’s.

“Cannabis clearly works in epilepsy,” said Mac Burnham, a U of T professor emeritus and co-director of the Epilepsy Research Program at the Ontario Brain Institute.

Burnham wants to focus on treatment ratios between CBD and THC – the principal psychotropic in cannabis – because patients say they work better together. But he had to stop his experiments because of delays in getting a licence from Health Canada.

Scientists at the summit were cautioned to guard against their research becoming tainted by perceived bias or influence, especially by tobacco and alcohol companies that are moving into cannabis.

“We have to be careful to protect our independence,” said Dr. Bernard Le Foll, a professor at the Institute of Medical Science who is also on the TC3 steering committee. But he added that in some cases involving medical cannabis research, there are partnerships with pharmaceutical companies that are “beneficial and appropriate.”

The summit was told the need for research is growing along with the scope of the potential public health aspect. Approximately 10 per cent of Canadians have consumed cannabis in the last year and 40 per cent have used it at some point.

CBD was singled out for the particular concern around the lack of understanding about  how it works.

“We really need to know what are the risks associated with its use,” said Dr. Romina Mizrahi, an associate professor in the departments of psychiatry, pharmacology and toxicology and the Institute of Medical Science who focuses on youth mental health and addiction.

“Anecdotally, we have seen an increase of patients with psychosis coming into the clinic using CBD for treatment,” said Mizrahi, a TC3 steering committee member.

About nine per cent of users develop cannabis dependency, but society has to balance those harms against opioids, said Daniele Piomelli of the University of California, Irvine, the keynote speaker at the summit.

“Cannabis can cause acute toxicity but there is no evidence of lethality, even after decades and decades of use.”

He also said research suggests the human body – which has its own endocannabinoid system – could one day be stimulated to enhance such things as energy levels, mood regulation and pain reduction, the same way cannabis seems to.

“We could use our own cannabinoid system to achieve the same effect, and that would be better than administering THC,” said Piomelli.