To Smoke or Not to Smoke, That is the Question: How Cannabis Impacts the Cardiovascular System

The devil’s lettuce. Dope. Pot. Grass. Reefer. Ganja. The street names for cannabis are seemingly endless. For non-users, it may seem like the culture around cannabis includes its own language that requires a dictionary to understand.

Anecdotally, something that people may notice when “smoking trees” is that their heart beats a little faster. While this feeling doesn’t stick around for long, it highlights that even a single use of cannabis can alter normal heart function.

When cannabis was legalized in Canada, there was very little understanding of how these types of products impact the cardiovascular system, both acutely and chronically.

Dr. Jamie Burr and recent PhD grad Dr. Christian Cheung in the Department of Human Health and Nutritional Sciences wanted to evaluate how different cannabis products acutely impacted the cardiovascular system. Comparing products where the predominantly active ingredient is cannabidiol versus THC (which is psychoactive), they found that the THC form of cannabis does elicit a small, but notable, degree of acute cardiovascular changes.

“Our interest was in seeing how acute use of cannabis inhalation perturbs the heart and arteries,” said Cheung. “We wanted to see if the physiology of smoking contributes to cardiovascular pathology.”

With the legalization of cannabis for non-medicinal purposes on October 17th, 2018 — a day likely remembered by many — there was no need for secrecy, so the sector saw a boom in business. However, research on the effects of cannabis did not. As Cheung explains, “Legislation didn’t catch up with research needs.”

There are also several ways to consume cannabis that could potentially influence how it impacts the human body. Burr and Cheung were interested in comparing traditional smoking with vapourizing. The latter method applies a dry heat to the product that produces no smoke and is often marketed as a “safer” way to inhale cannabis. However, such claims have not been fully tested.

The research team found that THC-predominant cannabis caused an increase in heart rate and blood pressure. In contrast, cannabidiol-predominant cannabis elicited little change. Interestingly, the method of inhalation did not impact the cardiovascular changes seen with THC cannabis.

It is important to note that participants used in this study were generally healthy, habituated cannabis users.

“We definitely did not have any issues recruiting participants,” laughs Cheung.

With so much still to learn about the impact of cannabis inhalation on our health, future studies will need to focus on older individuals, or those suffering from chronic illness, who turn to cannabis for medicinal relief.

Another key message from the study, say the researchers, is that the magnitude of cardiac physiological responses draws parallels to those seen during acute cigarette inhalation.

Given that cigarettes are known to increase the risk of a cardiovascular event, is this something for cannabis-consuming connoisseurs to worry about?

“This study wasn’t meant to describe one as better than the other,” explains Cheung. “The context is important. There isn’t anything in our study to suggest that ‘oh my gosh, cannabis will kill you.’  But it does demonstrate that it isn’t necessarily benign.”

Read this study in the Journal of the American Heart Association.

Read about other CBS Research Highlights.