Cannabis indica and Cannabis sativa are two similar but distinct plants used for medicinal and recreational purposes. C. indica is generally understood to have a higher level of THC than CBD, while C. sativa will typically have higher CBD than THC. However, a recent study shows indica and sativa labels on cannabis products do not always reflect these chemical differences, nor genetic differences between the two species. Researchers at Wageningen University & Research and the Canadian Dalhousie University instead discovered, through gas chromatography (GC) and next-generation sequencing (NGS) methods, that the greatest difference between products labeled indica or sativa was the terpene profile of the products.
The study involved the testing of nearly 300 samples labeled as sativa, indica or hybrids. Chemical analyses of terpenes and cannabinoids were conducted through GC with a flame ionization detector (FID), and whole-genome DNA was extracted from the samples to prepare genotyping-by-sequencing libraries. The results showed that the cannabinoid profiles and genomes of indica and sativa-labeled products were nearly indistinguishable from each other, and that terpene content was the greatest predictor of how a certain product would be labeled.
Sativa-labeled products were found to have higher concentrations of bergamotene and farnesene, which are associated with tea-like and fruity aromas. On the other hand, indica-labeled products were found to have higher myrcene, guaiol, γ-eudesmol and β-eudesmol content, contributing to a more earthy aroma. The researchers also identified a small number of gene clusters that differed between differently labeled products and accounted for these terpene expression differences. This study was published in Nature Plants.
“Unlike other high-value plant species, the labeling of cannabis is highly unreliable. This is highly undesirable, particularly for patients who use cannabis as a medicinal product and who benefit from good, consistent quality,” said co-author Robin van Velzen. “Producers should display the terpene profiles instead of an unreliable name like Indica or Sativa. A number of companies fortunately do that already, but yet there is no standardized measuring and naming convention. Reliable information is essential, particularly for medicinal uses.”
The study also found samples sold under the same product name, such as “Lemon Haze” or “OG Kush,” were in some cases more genetically different than those sold under a different name. The researchers stated that retailers and consumers should be aware of these labeling inconsistencies, and recommended that a more scientific approach be adopted in the cannabis industry to relay accurate information through product labeling.