Question Everything, Especially When There Are No References

First off, let me thank you for commencing to read this long overdue article. At Concentration 2019, I discussed the scarcity of scientific references in the mainstream media when reporting on cannabis science and medical benefits. Often, there is a perpetuation of information that is devoid of citations for our industry to more appropriately evaluate content and claims. In time past, due to the federal stance on the plants, universities have typically not been permitted to conduct research on cannabis. Or, they’ve fretted over whether they’d lose federal funding. Perhaps some potential researchers thought of cannabis as a joke, a Schedule I, just-for-fun vice of undergraduate freshmen.

Not all scientific research needs to come from universities, however. In fact, you’ve likely done a bit of research of your own when cycling through myriad products on dispensary menus. An Excel spreadsheet works well for keeping track of products, manufacturers, and chemical content, especially if you’re in a state where terpenes are thankfully on the label (Nerdy? Yes. But you are reading this blog, after all.) The point is, when something sounds medical or scientific, it warrants a proper citation as to where this information came from, whether anecdotally sourced or published in a scientific journal, or whether the “evidence” is a personal hypothesis of the author. Without this critical information, how are any of us to know that it represents reality, or whether it was pulled from out of the ether? After all, anyone can make any claim at any time, especially in such a rapidly growing industry. But where is the proof?

We published an article on myrcene’s supposed ability to help ferry cannabinoids across the blood-brain barrier, a trek which cannabinoids obviously can do without the terpene’s assistance. Perhaps you’ve heard the folklore regarding eating ripe mango prior to ingesting cannabis? In working on the soon-to-be-released book The Cannabis Terpene Experience, I became a reference archaeologist, and I dug and I dug, hoping to come up with some shard of scientific substantiation for this myrcene claim. I solicited the services of my assistant editor and some of our advisory board members. Surely someone, somewhere has unearthed this reference?

Some websites make this claim regarding myrcene and include zero references. Others rather blindly and deceivingly provide references, such as Ethan Russo’s famous “Taming THC” paper. [1] But I’ve searched for blood-brain barrier in Russo’s paper, with and without hyphenation, and for BBB, and there are no mentions of this term. I found a section regarding myrcene in a book chapter, whose authors came to the same conclusion, saying: “perusal of claimed references in the popular literature shows a lack of hard data regarding brain transport.” [2]

Hordes of people are utilizing cannabis with each passing day. Many of these people are not scientists or medical doctors, nor do they want to rummage through lots of complex jargon. They need information, however, and often, the World Wide Web is going to be the virtual library for research. And likely, and sometimes misguidedly, they’ll place trust in the source, and treat the content as gospel, without much questioning.

If you have scrolled through our blogs and magazines, you’ve likely noticed lots of scientific references listed at the ends of these articles. We pride ourselves on scouring the scientific literature first, prior to just hyperlinking secondary media sources. There’s nothing wrong with citing secondary media sources. That’s what our publications are, after all. But it is important to accurately portray products, medical claims, etc., with proper science that backs up the claims, whether a formalized journal study, a company white paper, or anecdotal patient feedback. It’s all data, and that data needs to have proper references.

In addition, you may have noticed our unorthodox practice of including journal impact factors as well as the number of times a specific article has been cited in the scientific literature. In chatting with Steven Bennett, Ph.D., we felt this was warranted to help guide readers who may not have scientific backgrounds since looks can be deceiving. [3] How many times have you read an article in the secondary media that misconstrued the nature of a scientific study?

A journal’s impact factor provides a numerical scale of how impactful that journal has been on the scientific community. The higher the number, the stronger the impact. Some journals are very specific, like Applied Spectroscopy, and these can have lower numbers just because they don’t affect as large of a swath of the scientific community. Other journals, like Nature, have a much broader content scope, and these tend to have larger impact factors.

Additionally, noting how many times an article has been cited can provide a good gauge regarding how trustworthy that reference is. Some newer journals, though, like Cannabis and Cannabinoid Research, have not yet been assigned impact factors, and therefore, the number of times the article has been cited can provide a supplemental metric. The citations number can be inflated on sites like GoogleScholar, where non-peer-reviewed scientific literature can also make the cut. So, we’ve begun using ResearchGate where possible to provide a more accurate reflection of the article’s impact.

As an example, say you see that a journal has an impact of over 5, but the article being cited is from 1968, and has only been cited twice. Not very impactful, was it, despite perhaps being in a decent journal? On the contrary, if the impact factor is less than 2, but the article is from 2017 and has been cited 213 times, that research is likely impacting the community.

This system is not perfect, but it does provide some additional levels of translucency with which, you, dear reader, can evaluate the science behind the claims. And by providing real references, we have chosen to lead by example and demonstrate the legitimacy and validity of the cannabis industry as a whole. And if you made it this far in my rant, thanks for listening.


[1] Russo, E. “Taming THC: Potential Cannabis Synergy and Phytocannabinoid-terpenoid Entourage Effects.“ British Journal of Pharmacology, vol. 163, 2011, pp. 1344–1364. [journal impact factor = 6.81; cited by 408] [2] Hartsel, J. et al. “Chapter 53: Cannabis sativa and Hemp.” Nutraceuticals: Efficacy, Safety, and Toxicity, edited by Ramesh C Gupta, Elsevier, 2016,  pp. 735-754. [journal impact factor = N/A; cited by 14] [3] Bennett, S. “Hope to Cope with Scientific Literature.” Terpenes and Testing Magazine, Nov-Dec 2018.

Image Credit: dullhunk/Flickr

About the author

Jason S. Lupoi, Ph.D.

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