Research

Health Impacts of Cannabis

While the evidence on the medical applications of cannabis is limited, there are risks associated with regular cannabis use. Ongoing research is improving what we know about both risks and benefits.

Clearing the Smoke on Cannabis Series

The Clearing the Smoke on Cannabis series looks at how cannabis use affects mental and physical health, and discusses implications for policy and practice. Prepared and peer-reviewed by expert researchers in the field, this series addresses what we know about the health effects of cannabis use, what we don’t know and what needs further investigation.

Edible Cannabis Products, Cannabis Extracts and Cannabis Topicals

A completely new line of cannabis products is now available for purchase in Canada. Edible cannabis products, cannabis extracts and cannabis topicals have unique health and safety risks that are different from the risks associated with dried cannabis.

With these products, it is important to know that:

• Edible cannabis products can increase the risk of over-consumption and subsequent cannabis poisoning.
• As edible cannabis products look like “normal” food and beverages, there is an increase in the risk of unintentional ingestion, especially by children.
• High-potency cannabis extracts increase the risk of cannabis poisoning, even more so than dried cannabis.
• Regular use of these products has been associated with problematic cannabis use, cannabis use disorder and mental health disorders.
• Research on cannabis topicals, including the use of CBD products you apply to the skin, is very limited. However, there is a growing interest among dermatologists and consumers in these products.
• Health impacts associated with long-term use of edible cannabis products, cannabis extracts and cannabis topicals is unknown.

Medical Use of Cannabis and Cannabinoids

About 13 per cent of people living in Canada report using cannabis for medical purposes. This includes people with authorization from a healthcare provider and those who may be self-medicating.

There is growing evidence that the use of cannabis, cannabis-based products and medications (with THC, CBD or both) may be helpful in managing symptoms associated with certain health conditions, such as:

• Chemotherapy-induced nausea and vomiting
• Symptoms of multiple sclerosis
• Neuropathic pain
• Symptoms of some seizure disorders

Many people report that cannabis helps with a wide variety of health conditions, such as sleep, pain and anxiety. However, the available clinical evidence does not support many of the self-reported benefits or the use of cannabis to treat most health conditions, especially as a first-line treatment option.

Based on existing research and because of the associated risks of harms, cannabis use should only be considered for people who do not respond to first- and second-line treatments. People should speak with their healthcare provider before using cannabis for medical purposes.

Of the people in Canada who report using cannabis for medical purposes, most (74 per cent) do not have an authorization document from a healthcare professional and may be self-medicating. People without healthcare authorization who may be getting cannabis from the regulated or illegal market do not have safeguards in place to protect their health and safety.

These safeguards include guidance from a healthcare professional on dosing, potential medication interactions and adverse effects, how to reduce the risk of associated harms, and other available treatment options.

Cannabis Use during Pregnancy

An estimated 16.9% of individuals of childbearing age (15–44 years) reported past-year use of cannabis in 2015 and 2% to 5% of pregnant individuals reported using cannabis during pregnancy. There is little evidence to suggest an association between cannabis use during pregnancy and increased risk of premature birth, miscarriage or major physical abnormalities. However, frequent cannabis use during pregnancy is associated with:

• Low birth weight and is part of a cluster of risk-factors correlated with other adverse birth outcomes;
• Altered neurodevelopment and cognition, and academic under-achievement; and
• Behavioural disturbances among children and young adults, including attention deficits, increased hyperactivity and impulsivity, and increased likelihood of delinquency and substance use.

Types of Cannabis Products 

On October 17, 2019, the federal government made it legal to purchase and consume edible cannabis products, cannabis extracts and cannabis topicals.

What are these products? In the simplest terms, they are defined as follows:

These new cannabis products carry with them unique health and safety risks that are not associated with consuming dried cannabis. It is important to be aware and informed of these risks before choosing to use edible cannabis products, cannabis extracts or cannabis topicals in order to minimize adverse health outcomes.

In the months leading up to legalization, CCSA released a series of public education resources about the new cannabis products. The resources include information about the associated health and safety risks, how to lower the risks or adverse health outcomes, the differences between ingesting and inhaling cannabis products, and how to safely store your cannabis products.

Edible Cannabis Products, Cannabis Extracts and Cannabis Topicals: What You Need to Know

Each of these types of cannabis product has its own attributes and uses.    

Edible cannabis can come in a range of products that are meant to be consumed by eating or drinking. Although some edible cannabis products might look like normal food items, they are not. These products provide no nutritional value.

Cannabis extracts can be in solid form (hash or hashish) or in liquid form (oil intended for vaping). These products can be vaped, smoked or ingested. Cannabis extracts can vary widely in their THC and CBD concentrations. Some extracts, such as cannabis oil distillates and shatter, can have up to 99% THC, whereas others can be mostly CBD with little THC. High-strength extracts can increase the risk of over-intoxication, especially among those who are new to cannabis.

Cannabis topicals are for application directly to the skin, hair or nails. The risk of intoxication and impairment following the application of cannabis topicals is believed to be low, although there has yet to be thorough research evaluating these potential effects.

Our primer provides a brief overview of each of these different type of cannabis products and their associated properties.   

Youth and Cannabis

With the legalization of cannabis, youth are seeking credible information from individuals they know and trust on the benefits and harms of cannabis use. They want to know the whole story. Young people are ready to have the conversation, but many who interact with them are not well prepared for it.

CCSA developed a communication guide to help educate youth allies on how to have safe, unbiased and non-judgmental conversations with young people about cannabis. By taking a harm reduction approach and providing a basis for communicating accurate information about cannabis, youth allies will be able to better support young people in making informed decisions about their cannabis use.

Since launch, the guide has had successful uptake from youth allies, many of whom indicated the guide effectively facilitated their conversation with youth about cannabis. More information about uptake and usage can be found in CCSA’s Cannabis Communication Guide Impact Story.