Edible Marijuana – Does it affect the Voice?

Marijuana use is quite common in the artist community. Now, with many states legalizing marijuana, use may be increasing, with younger exposure.

Artists often ask about the effect of marijuana on the voice and we have focused on what happens when it is smoked. However, what happens to the voice when marijuana is eaten instead?

Smoking anything is risky to the vocal cords, as it induces laryngitis which increase the risk of vocal bruising and permanent injury. Lung irritation and chronic bronchitis are common in smokers of anything, including marijuana. I often suggest a work-around due to my concern about this, which is ingestion (eating or drinking) of marijuana. This does appear to come with a lower risk to vocal health. A theory has been circulated that marijuana use in any form causes dilation of blood vessels, resulting in the same risk of vocal bruising as smoking. This theory assumes the following:

  • Orally ingested marijuana results in dilation of blood vessels
  • Dilation of blood vessels increases the risk of vocal bruising

If these two points are true, then it would change how I counsel my singers and professional voice user patients away from even edible marijuana. So I took on the task of reconsidering my conclusion that edibles are safer. Perhaps this new theory was correct?

I did an extensive literature search and found a recent article which reviewed the existing studies on the subject. Though published in an open source journal, the publications that were referenced were credible. The following was found:

  • There is no clear conclusion about the effects of marijuana/THC on vasculature. This article reviewed 112 articles that had been published in peer- reviewed journals and still does not conclude that THC causes blood vessel effects.
  • There is significant “evidence for vasoconstrictive effects of cannabinoid administration.” This means there is evidence that blood vessels get smaller. This contradicts the theory that edibles dilate blood vessels in the vocal cords. One must assume that the above theory was not based upon any research.
  • The review article also states “Early experimental results in the rat have hinted to a vasoconstrictive activity of THC comparable to that of norepinephrine (Adams et al., 1976). The fact that a simple vasodilation does not account for all of the substances’ complex influences on cardiovascular tone was strengthened by the description of the “triphasic” or “triple” effect (Siqueira et al., 1979; Varga et al., 1996; Malinowska et al., 2012).”
    Again, the effects of marijuana are complex and may be dilation or constriction of blood vessels, but evidence points to constriction.
  • There is also no proof that blood vessel dilation increases the risk of hemorrhage. For example, Viagra, a drug that works because it dilates blood vessels, is listed as having no effect on the voice by The National Center for Voice and Speech

Both of the premises were therefore incorrect. There is no evidence that ingestion of marijuana increased the risk of vocal hemorrhage.

These types of casual conclusions, based on no real reasearch, are dangerous to a community that is already struggling to overcome myths about health. Misinformation often spreads when one person’s opinion is portrayed as fact without substantiating research. While intuition is important, these days more than ever, we must differentiate fact from opinion. Those in the practice of giving advice need to be transparent about whether or not our advice is research and fact-based, we must revisit our opinions, review existing literature, and keep discourse active. Based on this process, the evidence clearly supports that ingested marijuana poses no risk of vocal hemorrhage and is far safer than inhaled.

References
Richter JS, Quenardelle V, Wolff, V et al A Systematic Review of the Complex Effects of Cannabinoids on Cerebral and Peripheral Circulation in Animal Models. Front Physiol. 2018; 9: 622.

http://www.ncvs.org/index.html