Reefer badness: Doctor warns of possible impacts of recreational cannabis on public health

OTTAWA (NEWS 1130) – A former head of the Canadian Medical Association says more needs to be done to raise awareness of the public health impact of legal recreational weed.

Doctor Chris Simpson — the vice dean of Health Sciences at Queen’s University — has told the Heart and Stroke Congress in Ottawa that every joint has a mixture of 70 chemicals, all of which can act on the heart and blood vessels in unpredictable ways.

“The degree of knowledge we have about the potential benefits and harm of cannabis is really in its infancy,” Simpson said. “But the harm seems to greatly exceed any potential benefits.”

Simpson explained THC attaches to receptors in the brain and blood vessel walls that can promote plaque growth in the arteries. He said it can also make the blood sticky, creating clots, which can lead to vascular diseases like stroke, heart disease, and heart failure.

“There is this huge popular misconception about cannabis, driven by social media and the cannabis industry, that it is a medicine or it is harmless,” Simpson added. “I worry when people say that cannabis is a natural product that has been used for a thousand years and so it must be safe. Countering that belief is tough. There are huge gaps between what people believe and what is reality.”

Among his concerns is something doctors have described as “a really mysterious condition in habitual users.” Cyclic Vomiting Syndrome can lead to dehydration, Simpson noted. He also flagged edibles — which are set to be legalized this month — as a concern, citing a slower absorption rate of THC can lead some users to consuming too much before actually feeling high.

“It hits you like a ton of bricks at the one-hour mark or so and you can overdose very quickly because of the delayed reaction,” Simpson said, adding he worries about kids accidentally eating these pot products.

Simpson would like to see the impacts of marijuana on vascular health studied more extensively.