How to choose your strain: It's complicated, according to Canadian scientists
In August, researchers at the University of British Columbia published a study comparing 33 different strains of cannabis — all of which contained roughly similar percentages of THC and CBD to the other strains, they found.
You could come to the same conclusion by looking at the potency results on pot in dispensaries across a state like Colorado, where such testing has been mandatory for several years. The numbers fall into a predictable range, with a couple outliers.
“THCA content ranged from 0.76 to 20.71%,” said the study, which was published in Scientific Reports.
So basically, here in Colorado, our pot tests higher than Canada's pot, NBD. (A couple legendary strains here consistently test over 30% THC.)
Still, the study has drawn media attention.
“New Research Shows All Marijuana Strains Basically The Same,” said one headline in Forbes.
The study authors, who measured 32 cannabinoids in a chemistry lab, had hypothesized that listing THC and CBD content alone was “insufficient” to account for the various effects people attributed to different strains.
This sounds like something organic growers have been saying for years: It’s not all about THC. When Colorado began requiring potency testing for recreational cannabis in 2014, these longtime growers grumbled. It was an oversimplification, they said; a reductionist spin on the complex “synergy” that creates a particular strain’s effects.
Still, here in Colorado, it's hard to sell anything testing below 20% THC. (Colorado retailers are required to list potency numbers beside each strain.)
CBD strains are the exception. Strains that are bred for high-CBD content usually have a very low percentage of THC. This finding was confirmed by the Canadian study published in Scientific Reports.
The study's conclusion was that breeding for THC content is reducing the overall genetic diversity of cannabis.
(A lack of genetic diversity is a problem, agriculturally-speaking, because it makes a crop more vulnerable to pests and disease.)
This conclusion doesn’t seem terribly surprising, if you’ve spent time in a grow. The grower selects a high-performing “pheno” (short for phenotype, or the outward appearance of one set of genes), then clones it, creating another plant with the exact same genotype.
It’s also not surprising, because as the cannabis industry becomes more industrial, it’s likely to meet the same fate as other kinds of modern agriculture. (American agriculture lost the vast majority of its genetic diversity over the last few decades.)
This study may not be groundbreaking, but it still raises important questions about the future of the cannabis industry. As the lead author explained to Canada’s Global News, medical patients could benefit from more research into the lesser-known cannabinoids.
“People have had informal breeding programs for a long time,” one of the scientists told reporters. “In a structured program, we would keep track of the lineage, such as where the parent plants came from and their characteristics. With unstructured breeding, which is the current norm, particular plants were picked for some characteristic and then given a new name.”
Still, their study confirms something that even “informal” organic gardeners have been saying for years: It’s not all about THC.
And eventually, scientists may confirm something that sounds more like common sense: The best strain is the one that works best for you.