Regulators have spent the past 70 years trying to figure out how to regulate tobacco. Now a fast-changing recreational drug use landscape in Canada that includes three legal products — tobacco, vaping and cannabis — means regulators will have to figure out the interplay of the three, says an expert in public health policy.

Between 35,000 and 45,000 deaths in year in Canada are attributed to smoking, about 30 per cent of all cancer deaths. However, cannabis and vaping are challenging the traditional categories of “good” and “bad” drugs, said David Hammond, who was in Ottawa on Monday to speak at the biennial Canadian Cancer Research Conference.

The evidence about benefits and harms can be confusing and contradictory. For example, vaping can help people to stop smoking. It can also help to sustain smoking. Most worrisome, vaping also appears to promote the uptake of regular cigarettes among youth, said Hammond, the Canadian Institutes of Health Research chair in applied public health at the University of Waterloo.

The sale of e-cigarettes has increased sharply in both the U.S. and Canada, with a large proportion of those new sales to teens. While e-cigarettes have the potential to help adult smokers quit regular cigarettes, there were no parallel increases in e-cigarette use among adults, said Hammond.

“We are not seeing the potential benefits, but we are taking the potential risks.”

Among youth, there is also a strong association between vaping first and going on to smoke cigarettes. This might be because youth who are predisposed to do one risky thing will go on to do another risky thing, said Hammond, who led an eye-opening study reported earlier this year that found an increase in youth vaping in Canada. While 8.4 per cent of 16- to 19-year-olds reported vaping in the past 30 days in August-September of 2017, it had increased to 14.6 per cent by the same period the following year, a jump of 74 per cent.

While teen smoking has been on the decline until recently, Hammond’s study also pointed to an increase in youth smoking regular cigarettes between 2017 and 2018, from 10.7 per cent to 15.5 per cent. The study presented the first data since the major tobacco companies launched and advertised their own e-cigarette brands in Canada following the adoption of Bill S-5, which legalized e-cigarettes with nicotine in May 2018.

Vaping among young people is a concern, even if they don’t go on to smoke cigarettes, said Hammond. Although e-cigarettes are less harmful that smoking, especially when it comes to cancer risk, they do contain nicotine.

For regular smokers, e-cigarettes are only beneficial if the smoker switches over entirely. There may be little or no reduction in risk for those who smoke both e-cigarettes and regular cigarettes.

About 80 per cent of the cases of the mysterious lung disease that attracted attention earlier this year have been attributable to vaping cannabis oils. So far, there have been almost 2,000 serious cases in the U.S. and more than 30 deaths, said Hammond.

“Your lungs are much more sensitive than digesting it through your stomach,” he said. “No one knows what the contaminants are in these oils. If you are buying something on the black market, then all bets are off.”

Hammond points out that tobacco, e-cigarette and cannabis companies are now integrated, with tobacco companies having a stake in vaping products and cannabis. Last December, the tobacco company Altria Group invested in the cannabis producer Cronos Group. Another tobacco giant, Philip Morris, sells an electronic burn-free “tobacco heating system” that delivers nicotine to users without smoke.

In June, the Canadian Cancer Society called for immediate government action to address the increase in youth vaping in Canada. Last month, Ontario announced it would ban ads promoting vaping products in convenience stores and gas stations beginning in January.

“That brings them to the absolute minimum standard,” said Hammond.