It’s been a good decade for cannabis. It started with the growing popularity of hemp seeds, took a brief foray into hemp protein powder, witnessed the legalization of recreational marijuana in a full 20% of the country, and most recently culminated in the legalization of industrial hemp. The rising star of the family isn’t its seed, fiber, or even its psychoactive component tetrahydrocannabinol (THC), though—it’s an until recently obscure chemical called cannabidiol (CBD).

Unlike THC, CBD doesn’t bind to our cannabinoid receptors (which we have in our central nervous system and immune system) and so it has no psychoactive effects. That doesn’t mean it’s inert, however; it might not bind to the sites, but it appears to modulate them, thus altering the effects of cannabinoids (native and foreign alike) that do bind. It’s this modulatory effect we’re now investigating medically, and it’s also responsible for the sudden effusion of CBD into our lives, conversations, advertisements, and Instagram feeds.

CBD companies tout a myriad of benefits, some contradictory. According to purveyors, it can give you more energy but also level you out. It can help you sleep but also perk you up. It reduces anxiety, kills cancerous cells, and quenches inflammation. In short, it does just about everything. What about according to less-biased sources? What do we really know about CBD?

What The Research Says About CBD

The short answer is “not much”. While more studies are being performed on CBD every year, to date most studies are preclinical, meaning they don’t involve human subjects. Preclinical trials are critical to the scientific process, but historically most preclinical findings don’t pan out once tested in humans, so we should be skeptical of preclinical CBD results for the moment.

Only a limited number of clinical CBD trials have been completed, and so far they exclusively target subjects with neurological issues like epilepsy or anxiety disorders (e.g., panic disorder or post-traumatic stress disorder)—not healthy individuals. Discovering a medical benefit of CBD for these problems would be fantastic, but it wouldn’t translate to a benefit to everyone.

Many trials on CBD also involve THC, which makes sense under the banner of medical marijuana since the two are naturally entwined, but which also makes it impossible to isolate CBD’s effects. It’s interesting to see how CBD may change THC’s effects (for example, it appears to reduce the anxiety sometimes associated with THC), but just because CBD combined with THC affects a person one way doesn’t mean it will have the same effect separate from THC.

Finally, all trials (including preclinical ones) have tested large, acute doses of CBD and not chronic intake of small doses. A typical studied dose is 300-600 milligrams—far above the 10-50 milligram doses commonly seen in commercial CBD products. This doesn’t mean chronic, low-dose CBD intake won’t have an effect; it means we have no idea what that effect is or how large it would be.

Does CBD Do Anything?

It’s not all storm clouds. In therapeutic doses, CBD does have a few positive effects—at least for individuals with certain conditions. The best evidence we have is in the treatment of epilepsy and anxiety disorders.

For epilepsy, CBD administration has been shown to help reduce seizure frequency. In fact, the FDA recently approved the first CBD-based pharmaceutical, Epidiolex. The drug is approved to treat two rare forms of epilepsy (Lennox Gastaut syndrome and Dravet syndrome), and the dosage of CBD is high: 10 to 20 milligrams per kilogram daily. If you suffer from one of these diseases, CBD could help!

We also have evidence that CBD can help with anxiety disorders (in 300 to 600 milligram doses). The caveat here is that while CBD does have demonstrable anti-anxiety effects, so far we’ve only tested for these effects in subjects with demonstrable social anxiety disorder and not, say, the general, mild trepidation about falling on a rope that the average climber may experience. To be more explicit, an experiment found that CBD reduced anxiety during a simulation of public speaking compared to a placebo, but subjects were still significantly more anxious than “healthy” controls (who were not given CBD)—it reduced irrationally extreme anxiety to greater-than-normal anxiety, but didn’t come close to eliminating it.

Beyond these applications, the evidence is too limited to make a conclusion. With more trials underway, we may find new benefits soon—but even in these cases, it’s likely we’ll be looking at 300+ milligram doses, not casual, commercial doses.

Label Accuracy Is Also a Concern

There’s one more point to be made about commercial CBD: it’s unregulated. I know, every CBD manufacturer touts their process and third-party testing and purity of its products, but a study done by the Journal of the American Medical Association found label accuracy on CBD products to be… less than perfect. About 70% of the products had inaccurate labels (two thirds contained less than advertised, one third more), and eighteen of the eighty-four products tested contained THC—one contained 6.4 milligrams per milliliter, more than enough to get you high. This problem is hardly limited to CBD products (another study found that THC products suffered the same problem), it’s just something to be aware of.

Looking to the Future

There are some promising applications for CBD, but unfortunately, right now the evidence is limited and mostly of poor quality. At the very least, we can say that the advertised benefits are exaggerated and unlikely to apply unless you take a considerable amount. Even then, it appears CBD is better at fixing dysfunction (or modulating the effects of other cannabinoids) than augmenting an otherwise healthy person.

Time will tell, though—what we need more than anything is simply more studies. In the meantime, CBD appears to be relatively adverse effect-free, so regardless of any benefit it doesn't seem like it will harm you.

As a certified sports nutritionist (MS, CISSN), Brian Rigby works with climbers and other athletes at Boulder’s Elite Sports Nutrition in Colorado, writes at Climbing Nutrition, and discusses the scientific aspects of climbing performance as co-host of the ClimbSci podcast.

References

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  2. Commissioner O of the. Press Announcements - FDA approves first drug comprised of an active ingredient derived from marijuana to treat rare, severe forms of epilepsy. https://www.fda.gov/newsevents/newsroom/pressannouncements/ucm611046.htm. Accessed January 18, 2019.
  3. Blessing EM, Steenkamp MM, Manzanares J, Marmar CR. Cannabidiol as a Potential Treatment for Anxiety Disorders. Neurotherapeutics. 2015;12(4):825-836. doi:10.1007/s13311-015-0387-1
  4. Bergamaschi MM, Queiroz RHC, Chagas MHN, et al. Cannabidiol Reduces the Anxiety Induced by Simulated Public Speaking in Treatment-Naïve Social Phobia Patients. Neuropsychopharmacology. 2011;36(6):1219-1226. doi:10.1038/npp.2011.6
  5. Bonn-Miller MO, Loflin MJE, Thomas BF, Marcu JP, Hyke T, Vandrey R. Labeling Accuracy of Cannabidiol Extracts Sold Online. JAMA. 2017;318(17):1708-1709. doi:10.1001/jama.2017.11909
  6. Vandrey R, Raber JC, Raber ME, Douglass B, Miller C, Bonn-Miller MO. Cannabinoid Dose and Label Accuracy in Edible Medical Cannabis Products. JAMA. 2015;313(24):2491-2493. doi:10.1001/jama.2015.6613
  7. Iffland K, Grotenhermen F. An Update on Safety and Side Effects of Cannabidiol: A Review of Clinical Data and Relevant Animal Studies. Cannabis Cannabinoid Res. 2017;2(1):139-154. doi:10.1089/can.2016.0034

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