Indica, sativa, hybrid. Walk into any Colorado dispensary and the products on the shelves will be classified under one of those three familiar categories. Sativa cannabis supposedly gives you energetic, active highs, while indicas are relaxing and sedative, with hybrids falling somewhere in between.
Or so we’ve been told.
But that distinction is deceptive, suggests new research from the University of Colorado (CU) and Leafly. The classifications of indica, sativa and hybrid don’t actually correlate to the specific cannabinoids, terpenes and flavonoids that give a cannabis strain its flavor, and, through the entourage effect, give each strain specific medicinal effects. Those labels are good for describing the physical geometry of a cannabis plant, according to Brian Keegan, one of the coauthors of this study, recently published in Plos One. But as far as telling consumers anything important about the bud they’re about to ingest, those three labels are pretty much useless.
“[These] labels that are really popular and prevalent in the industry are not reliable indicators at all of the chemical composition of these plants,” Keegan says. “There’s not really a robust, valid way for people to describe these kinds of things.”
Keegan hopes this research will change that.
Keegan is an assistant professor of data science at CU. Most of his research centers around how Wikipedia covers breaking news events, but since moving to Colorado he’s become extremely interested in the intersection of data science and the cannabis industry. Because, as he explains, prior to legal cannabis, no one was keeping close data on sales, quality or chemical content of black-market weed. But with legalization there’s been an explosion of new data ripe with
research opportunities.
“There’s been a really profound shift in the role of data in this industry,” Keegan says. Now cultivators and retailers are required by law to keep detailed seed-to-sale records and information about their strains. Which scientists like Keegan are delving into and parsing.
In 2020, Keegan and one of his coauthors, Daniela Vergara, authored another study that examined how different cannabis strains “cluster” together in groups based on their chemotopic identity. That first study laid the foundation, Keegan says, and acted as an entry point to collaborate with Leafly on this much broader and more in-depth second study.
“By partnering with Leafly, we were able to access a larger database that was representative across six different states and 90,000 different strains,” Keegan says. That database included detailed profiles of terpenes and cannabinoids for each individual strain
it included.
“This is the largest analysis of cannabis strain data to date that we’re aware of,” Keegan says.
What they observed could change how cannabis is commercially labeled and sold in stores.
“We plugged in all this data and cranked it through these data science algorithms and discovered that there are three underlying clusters [of cannabis],” Keegan explains. Naturally, at first they thought those strain clusters would line up with indica, sativa and hybrids. However, when they tried to overlay those categories on top of what they were observing, it didn’t match up. Instead, the three clusters were sorting based on
terpene content.
One group had high content of caryophyllene and limonene terpenes, which are often associated with citrus flavors; another contained strains high in myrcene and pinene, often associated with earthy “dank” flavors; and the third group was high in terpinolene and myrcene, which create “diesel” scents and flavors.
Keegan says that these aren’t the only clusters that are possible, but they’re the ones that are most commonly found in commercial cannabis strains. Those clusters won’t just tell a user how a cannabis strain will taste and smell, but if there’s any credence to the entourage effect, they’ll also speak to the strain-specific effects to expect.
Keegan likens it to nutritional labels on food.
“If we were only reporting calories and fat on our nutritional labels, that would omit all these other nutrients and minerals and vitamins that are actually really important,” he says. “We’re currently in an analogous situation where all of the labels that are on [cannabis] products … are really kind of reporting calories and nothing else.”
As a result, Keegan says users who go to a dispensary to buy a specific strain for a specific reason (be it for a flavor preference, the type of high, or for a specific medicinal property like anti-seizure effects) might not be getting what they’re looking for.
“I think that’s a really big problem,” Keegan says. “You think you’re buying one thing, but that could be something completely different.”
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