
Last month, Canada’s Center for Addiction and Mental Health issued some interesting guidelines that address your question. Canada has been moving toward legalization, the authors argue, and that should be done in a deliberate way—with a clear plan to regulate the industry and safely inform the public on the best ways to use cannabis. They write: “A substantial extent of the risk of adverse health outcomes from cannabis use may be reduced by informed behavioral choices among users.”
This stands in contrast to the United States, where states have essentially woken up one morning and decided to legalize. The Canadian guidelines have been in the works for years. They even have a modest, progressive, Canadian name: The Lower-Risk Cannabis Use Guidelines, abbreviated LRCUG. I like this as an unwieldy acronym so much that I will use it going forward.
Good advice—it’s rare that any doctor would recommend burning any drug and inhaling its smoke over simply ingesting it. Smoking can complicate dosing, and it is frowned upon in hospitals. But most importantly, inhaling smoke irritates and inflames the respiratory tract, which can hypothetically lead to cancer, regardless of the source of smoke—whether it’s smoke from marijuana or tobacco, and probably even if you’re smoking pure kale or multivitamins. Inhaling wood smoke from a campfire can reduce lung function and cause chronic lung disease, if you spend enough time pulling it directly into your lungs. (Do you do that? Email me.)

Meanwhile marijuana smokers have been vaping since the dawn of time—if not in a portable capacity. I remember first meeting the enormous, iconic Volcano Performance Vaporizer about a decade ago. It’s a 10-pound, stainless-steel tabletop cone that costs $599 and shoots hot air through a disc filled with ground cannabis and up into a giant transparent balloon, which in my experience is then passed around at a party, and from which people take turns inhaling and becoming progressively less fun to talk with.
Still, vaping offers the safety advantage of allowing people to more easily calibrate doses. Inhaled cannabis goes almost immediately across the blood-brain barrier, and its effects are felt. This at least affords a person an opportunity to know when it would be wise to put down the vape.
This stands in contrast to the also-booming field of edible cannabis. Though this could seem like the safest route, the dosing question is even tougher, and overdosing more likely. Digested in food, the THC has to pass through the liver before traveling to the brain, which means it can take around an hour to achieve its maximal effect—depending on how much a person has eaten, and varying from person to person. This is not to mention variation in dosing from edible product to edible product, which is difficult to standardize across every single bite of brownie that comes out of every batch. It can be a guessing game.
So among edible products, the LRCUG recommend that people “identify and choose lower-risk cannabis products.” Drawing a distinction between identify and choose seems deliberate. I really appreciate Canada’s work here. They note that cannabis products with high tetrahydrocannabinol (THC) content “are more likely to result in harms.” Though not always—products can also contain varying doses of cannabidiol (CBD), which can counter some of the action of THC, meaning that choosing products with high CBD-to-THC ratios could “reduce some of the risks.”
Source: The Science of Smoking Versus Edible Cannabis – The Atlantic