Cannabis IQ: Almost half of Canadian pot users say they use daily. Here’s why regular use is risky

Click to play video: 'Is weed good or bad for you? Everything we know about the health effects of cannabis'
Is weed good or bad for you? Everything we know about the health effects of cannabis
Above: Is weed good or bad for you? Everything we know about the health effects of cannabis – Jul 5, 2018

Most Canadians don’t use pot. But those who do seem to use it a lot.

According to an exclusive survey for Global News by Ipsos, 21 per cent of Canadians say they currently use cannabis.

And while that number won’t change drastically post-legalization — only one in 10 of those who don’t currently use pot said they were likely to start after Oct. 17 — the overwhelming majority who consume marijuana use it regularly.

MORE: Sign up for Cannabis IQ, a weekly newsletter covering legalization

Forty-three per cent of users say they consume it daily, with another 29 per cent saying they partake once a week or more.

People who use marijuana that frequently may be increasing their risks of various health problems, according to Jason Busse, associate director of the Michael G. DeGroote Centre for Medicinal Cannabis Research at McMaster University.

Story continues below advertisement

It’s hard to list all the negative effects, as marijuana research has been so hard to do while it was illegal, so there simply aren’t enough strong studies to know everything about it, said Busse. Still, he doesn’t think consuming marijuana daily is good for you.

“It’s going to depend on the potency of the product, the experience of the individual, their metabolism, but it seems difficult to conclude that daily use is a very good idea.”

For one thing, smoking marijuana is associated with respiratory issues, he said, including a higher risk of chronic bronchitis. “We know that if you don’t smoke it, you’re not going to suffer the same risks of the respiratory effects.”

Unfortunately, according to the survey, 86 per cent of people choose to smoke their marijuana at least sometimes. Using edibles, oils, or even a water bong may mitigate some of those respiratory risks, Busse said.

The latest health and medical news emailed to you every Sunday.

Marijuana is also associated with some cognitive difficulties, particularly in young people. “There’s at least some studies that have suggested chronic marijuana use can be linked to lower educational attainment when smoking or consuming cannabis starts in adolescence.”

Story continues below advertisement

While it’s hard to say if that is exactly a causal relationship, there does seem to be a link between the two. Young people who are predisposed to psychosis might also have an earlier onset of symptoms if they’re frequent marijuana users.

There’s also some evidence, said Busse, that frequent marijuana use can change the structure of the brain.

“What we don’t know is, how long do those changes last? Are they linked to true changes in behaviour, and do they reverse after a person stops using the drug?”

The Canadian Psychiatric Association was concerned enough about the potential effects of chronic marijuana use on young people’s brains to issue a position statement in 2017 recommending that the legal age be set at 21 and that restrictions be placed on the amount and potency of what people can buy until the age of 25. These recommendations have not been followed.

WATCH: What Canadians need to know about recreational marijuana come legalization

Click to play video: 'What Canadians need to know about recreational marijuana come legalization'
What Canadians need to know about recreational marijuana come legalization

Busse is concerned by the survey’s finding that nearly half of adults who consume marijuana daily have children in their households. “We don’t know enough about the effects of second-hand smoke.” Also, many edible products, like candies, can appeal to children and increase their risk of overdose.

Story continues below advertisement

While overdoses aren’t fatal, they could involve hallucinations and warrant a visit to the emergency room, he said.

Also, the more often you use marijuana, the more likely you are to become dependent, he said.

“Once you become a chronic user it’s often hard to step away from that chronic use.”

Around one in 10 chronic users will become dependent, he said. That means stopping the drug would be difficult and people may experience withdrawal symptoms like loss of appetite, anxiety and sleep disturbance.

So how often should you consume marijuana, to mitigate these risks? The science isn’t there to tell you yet, Busse said.

“I do think that if individuals are able to reduce the frequency of consumption, it stands to reason that they would also be able to lower their risk of some of these adverse events.”

He’s happy to see that most people are unlikely to start using marijuana if they aren’t already. According to the Ipsos survey, 84 per cent of people say their frequency of use will remain about the same after legalization. Most people who aren’t currently using it say their habits won’t change.

Exclusive Global News Ipsos polls are protected by copyright. The information and/or data may only be rebroadcast or republished with full and proper credit and attribution to “Global News Ipsos.”

Story continues below advertisement

This Ipsos poll on behalf of Global News was an online survey of 2,000 Canadians conducted between Oct. 5-9. The results were weighted to better reflect the composition of the adult Canadian population, according to census data. The precision of Ipsos online polls is measured using a credibility interval. In this case, the poll is considered accurate to within plus or minus 2.5 percentage points, 19 times out of 20.

Sponsored content