A new study finds that most young adults do not understand the marketed levels of tetrahydrocannabinol (THC) in edibles, but the researchers have come up with a better way to communicate this knowledge on labels.
Data from 2015–2016 indicates that approximately 10 percent of the adult population in the United States and nearly 24 percent of the youth in the previous year had used cannabis.
Use has only grown since then— for example, one study showed that 33 percent of adolescents in grades 9–12 in California had used cannabis in their lives, and most of them had eaten edibles.
Edibles — items like cookies, brownies, and candy that contain cannabis — have raised concerns in recent years as their popularity has increased.
Marketing which imitates that of standard sweets is some cause for concern. Consumers often underestimate the potential effects of edibles— they may not know how much the products contain THC, the principal psychoactive ingredient in cannabis.
New research has therefore explored how the THC content of edibles is represented on labels, and how well this knowledge is conveyed to young consumers through different labeling systems.
Prof. David Hammond of the School of Public Health and Health Systems at Waterloo University, Canada, is the final and contributing author of the new study published in the Drug and Alcohol Dependence journal.
Prof. Hammond describes the reason for the research, saying, “The use of THC numbers to describe the potency of cannabis products has little or no significance for most young Canadians.”
“We have known for many years that people are struggling to understand the numbers behind food packages and cigarette packaging. Customers seem to have equal or even greater difficulty with THC numbers, which are used to show cannabis products ‘ potency.”
‘Traffic light’ labeling system best
Both Prof. Hammond and the team performed two experiments designed to determine how well different labels communicate cannabis potency knowledge.
To that end, 870 individuals aged 16–30 were recruited in Canada and completed an online survey.
The researchers randomly assigned one of three labeling conditions to the respondents in the first experiment: no label, a label describing the amount of THC in milligrams (mg), or a mark that used “doses” of THC per package.
The team used a traffic light system in the second experiment to label the cannabis products — green meant “low” potency, and red suggested “high” potency.
In the second experiment they also tested the effectiveness of no labels, those advertising THC for percentages, and labels with THC in mg.
The results revealed that marking the number of doses per product resulted in the best understanding of a THC serving — that is, more than 54 percent of respondents were right.
The traffic light system also made it easier for visitors to recognise THC rates in goods. Using this method approximately 85 percent of respondents correctly recognized items with low THC levels, and approximately 86 percent recognized high THC material.
Prof. Hammond and colleagues conclude:
‘ Few consumers can understand and apply quantitative THC labels; on the other hand, THC labels that provide’ interpretive’ information, such as descriptors, symbols or serving references, are more effective.’
The corresponding author of the study also states that’ Effective THC labeling and packaging may help to reduce the accidental overconsumption of cannabis edibles and adverse events that have increased the number of cannabis edibles.’
Prof. Hammond continues, “New regulations restricting cannabis edibles to a maximum of 10 mg per package are particularly important, since most consumers do not understand THC amounts.”
“Nonetheless, the findings suggest that consumers will need THC information for other items, including oils, concentrates, and dried flowers, to be easier to understand.”