Cannabis and its health effects

Countdown to cannabis With days until marijuana legalization, CTV Edmonton's Bill Fortier brings us the first part of five in a series about what we know, and what we think we know, about cannabis.

Cannabis will be legal in Canada in less than ten days, and local health officials hope to seize the opportunity to study the effects of marijuana on the brain.

“When you smoke marijuana, the cannabinoids in the plant actually hijack this system,” said Martin Davies, Pharmacology Professor at the University of Alberta.

Davies says the active chemicals in pot are THC and CBD. The THC provides the high, while CBD is associated with perceived health benefits.

The so called “cannabinoids” stick to the brains neurons so some of the messages from your body, on things like appetite, mood and even movement, don’t properly reach your brain.

Davies says when it comes to the medical benefits of marijuana use, things become a bit hazy.

“The medical benefits are somewhat controversial, simply because there are relatively few high-quality studies. There’s so much that we don’t know.”

Although the strongest studies do support that those who suffer from chronic pain and muscle spasticity benefit moderately from marijuana use, the biggest health concern for the general public comes from smoking the drug.

Davies says the smoke irritates the smoker’s lungs, and those who have a pre-existing condition like asthma will likely exacerbate it. Those looking to take edibles also run the risk of causing a permanent deficit in the ability to store and access memories.

Provincial health officials say the risks are worse for people under the age of about 25, impacting brain development along with learning and memory.

An Alberta Health Services Clinical Psychologist, Scott Purdon, is set to expand his study about smoking and then getting behind the wheel once pot is legal.

Purdon is studying a large group of young adults who use pot heavily to see how long the effects of marijuana last.

“We're asking them when the last time they used was and then measuring their cognitive status and their psychological status, and seeing how long it takes for that to change.”

Another U of A study will look into the impacts of marijuana on embryos, with researchers finding that T-H-C does negatively affect unborn zebra fish.

“It's a good starting point to take a look at this in humans, so we will be doing a lot of that very close monitoring to be watching and learning,” said Dr. Deena Hinshaw, Deputy Chief Medical officer of Health.

The results of the studies being done here in Edmonton and across the country will ultimately shape public policy on cannabis, as well as increased knowledge on the positives, and the negatives, of marijuana use.

With files from Bill Fortier