A prominent Winnipeg doctor says setting Manitoba's legal age to buy and use pot at 19 "sends the wrong message" that cannabis is more dangerous than alcohol.

Dr. Joel Kettner said he worries the perception will be that alcohol is less problematic, since the legal age to purchase and consume alcohol is 18 in the province.

"One of the messages that I would be concerned about sending out to our youth, to our young adults, to our public, is that marijuana is more of a concern than alcohol," said Kettner, a professor at the University of Manitoba's medical college and the former chief provincial public health officer.

"Setting the age for marijuana [at 19] while keeping alcohol purchases legal at 18, I think, sends the wrong message when we compare the dangers of these products."

The Progressive Conservative provincial government tabled legislation Tuesday outlining the rules around the upcoming sale and regulation of marijuana, which the federal government plans to legalize by July of 2018. The provincial rules include a ban on growing pot plants in the home for recreational use and setting the legal age at 19 to buy and use marijuana in the province.

Several provinces have indicated they will tie the legal age of purchasing pot to the legal age of purchasing alcohol, including Ontario — which has a legal age of 19 — and Alberta, where the legal age to buy controlled substances is 18.

Dr. Joel Kettner, a professor at the University of Manitoba's medical college, says doctors are still learning about how pot use affects brains of all ages. (CBC)

Justice Minister Heather Stefanson said Tuesday the Manitoba government took a "balanced approach ... a responsible approach" in picking 19 as the age at which Manitobans will be allowed to buy cannabis.

She said the age provides both health protection and helps keep the marijuana trade out of the hands of gangs.

"Young people live in homes and we want to make sure it is out of their hands," Stefanson said.

High schools are by no means free of marijuana and it's a place where we know that people under 18 have access to it and are using it. So I'm not sure I follow the logic of that. - Dr. Joel Kettner

"It will accomplish two primary goals: it will help keep cannabis out of the hands of our kids and away from the black market."

The reasoning behind that choice doesn't hold up, said Kettner.

"We know that right now, with the illegality of possession and use, that high schools are by no means free of marijuana and it's a place where we know that people under 18 have access to it and are using it. So I'm not sure I follow the logic of that."

The Canadian Medical Association recommended to the federal government in 2016 that the age to legally purchase and use cannabis should be set at age 21. The CMA said ideally the legal limit would be 25, because the brain is still developing until about that age. But the group said a lower legal age is needed to keep youth from turning to criminals to buy pot.

Kettner said doctors are still learning about how pot use affects brains of all ages.

"The brain develops and matures and changes throughout life. The whole issue really with substances that affect the brain is how much, how often and what kind of immediate harm, as well as long-term harms.

Denise Elias, the president of the MADD Winnipeg chapter, said the organization supports the legal age of 19, but wishes it had been set at 22. (CBC)

"It's the same message we would send out for alcohol, for example, and alcohol we know affects the brain in many ways as well as other organs of the body. Marijuana, we're still learning about that.

"I'm not by any means trying to encourage the use of it, especially in young people, but I think there is some arbitrariness to those ages."

MADD, school boards support age limit

The Manitoba School Boards Association originally recommended an age limit of 21 but on Tuesday said they supported the decision to set the age at 19.

"We believe it was important to try and limit access to youth to the substance," said Josh Watt, executive director of the MSBA.

"That said, given the fact that every other province seems to be going the way of 19, I think it's important that we achieved alignment in this province for the protection of our young people."

The president of Mothers Against Drunk Driving's Winnipeg chapter said they were hoping for a higher age limit.

"We're supportive of the age of 19 although we did ask for the age of 22 … based on the research, the medical research," said Denise Elias.

'It's ridiculous': retired detective

Retired police detective Bill VanderGraaf said the province may have to raise the age of legal alcohol consumption to match if they stay this course.

"I think they're going to have to increase the alcohol age then, too, because that's a far more serious problem in our society today," said VanderGraaf.

"I've seen many young people die from alcohol abuse in our cities over the years and simply put, it doesn't compare to cannabis, Mr. Pallister — it just doesn't compare to cannabis.

"We can send our young people, our 18 year olds to war, we can send them into a liquor store, but they … can't buy a little pot? It's ridiculous."

Local marijuana activist Steven Stairs said setting the age at 19 sets young people up to land on the wrong side of the law.

"I think it's going to predispose a bunch of 18 year olds to a) be criminals for using pot, and b) be more likely to start using alcohol than cannabis, which is totally detrimental to them."