The Internet says that you should eat a mango and the myrcene in it will get you extra high. Here is what science says.
The Mango Theory
Some things about cannabis are repeated so often that you think they must be true. One example of this is the “Mango Theory”. The story goes that if you eat a fresh, ripe mango 45 minutes before smoking cannabis, then you will be extra super duper high. You will be so high that you will crap rainbows.
How do we know this really works? Well, because the Internet said it would. Everyone and their mom have written an article about the Mango Theory. Here’s one example: Mango and Weed – A Match Made In Heaven. You can use Google to find 500 more that all say the exact same thing.
Myrcene: The Alleged Mango Culprit
So what magical compound is there in mango that might have this effect? Everyone cites a molecule called β-myrcene (I’ll just call it myrcene). Myrcene is in the class of molecules called terpenes, which are produced by plants and give off their characteristic odors. Myrcene is also found in hops, basil and lemongrass.
How does myrcene work according to the Mango Theory? There are two very specific ways (repeated in a large number of articles) that myrcene allegedly increases your high from cannabis:
- Myrcene increases permeability of the blood-brain barrier. Myrcene supposedly increases the speed that THC can cross the blood-brain barrier. In fact, many articles say that by eating a mango, you can decrease the time it takes to feel high from 7 seconds to just 4 seconds. I’m really expected to believe that anyone can tell a difference of 3 seconds?
- Myrcene increases activation of the cannabinoid CB1 receptor by THC. This is not totally implausible since there are molecules that can do this (they are called Positive Allosteric Modulators).
But here’s the problem: These articles were mostly written by 23 year old English majors (and they were probably high). Not that there’s anything wrong with that…but I doubt that any scientific fact checking went into their research.So what evidence could I find that either of these mechanisms is true?
None. Given the specific nature of these claims, surely there must be a scientific paper describing it? I searched everywhere and I could find nothing to support either of these mechanisms.
[July 2017 update: there is new evidence that terpenes can in fact increase CB1 receptor activation, but details of which terpenes have this property have not yet been released.]
What Does Myrcene Actually Do?
Now that we’ve established that most of what has been written about mango and myrcene is likely garbage, let’s move on to some actual science.
First of all, there is actually strong evidence that myrcene has psychoactive properties and that it is capable of modulating the effects of THC.
In mice, myrcene had sedative and muscle relaxant effects (although only at super high doses). In addition, it increased sleep induced by barbiturates. Another study in mice showed that myrcene had anti-convulsant effects. Lemongrass essential oil (of which myrcene is a major component) had anxiolytic effects in mice.
It is not surprising then that researchers at Steep Hill Labs saw a correlation between the sedative effects of different strains of cannabis and their myrcene content.
A high myrcene level in cannabis (>0.5%) typically results in the well-known ‘couch-lock’ effect of classic Indica strains while a low level of Myrcene (<0.5%) often results in the uplifting and vibrant effects most associated with Sativa strains.
Although not a published scientific study, their analysis involved 100,000 samples over 7 years, so it seems pretty solid.
GABA at the Intersection of THC and Myrcene
So what is this ‘couch-lock’ and what role does myrcene play in it? Couch-lock is when you are so stoned that you feel like you cannot even move (and therefore locked to the couch). There is a test in mice for this type of ‘cataleptic’ state where they place their front paws on a horizontal bar. Normally, this is an unnatural position for a mouse and they will quickly move. However, with a high dose of THC, the mouse will just sit there for an extended period of time.
GABA is an inhibitory neurotransmitter in the brain that acts through two receptors: GABA-A and GABA-B. GABA enhancers are synergistic with the cataleptic effect of THC in mice. Low doses of drugs with GABA activity (which do nothing by themselves) significantly increase the time the stoned mice are in the experimental ‘couch-lock’.
How is this linked to myrcene? Along with several other terpenes, myrcene enhances the effect of GABA at the GABA-A receptor. Furthermore, the anxiety-reducing effect of lemongrass essential oil (which contains myrcene) is reversed by a drug called flumezenil, which blocks a binding site on the GABA-A receptor.
These results indicate that myrcene, at a low dose that itself has no effect, can synergistically enhance the sedative effects of THC.
Can Mango Really Raise your Myrcene Levels?
So having established that myrcene does have psychoactive effects, let’s return to the issue of the mango. There’s one question I’ve had from the beginning: if cannabis already has so much dang myrcene in it, can eating a mango add that much more?
Myrcene is the primary monoterpene in cannabis and there can be quite a lot of it. Here is a study showing the levels of myrcene in different cannabis strains. Levels varied from 0.04% to 1.9% – almost 50-fold variation.
Like cannabis, different mango varieties also contain different levels of myrcene. One study assessed the myrcene content of 20 varieties of mango. They showed that the myrcene in the mango varieties ranged from 0.09 to 1.29 mg per kg of fruit.Let’s do the math and see how things add up. I’ll assume that 100% of the myrcene is absorbed and that the average person consumes a quarter gram of cannabis at a time and one whole mango (with 150 g of fruit). With average myrcene content, a person will ingest about 2 mg of myrcene from the cannabis and 0.086 mg from the mango. The mango only adds 4% more myrcene!
We can also look at the most extreme case of the cannabis strain with the lowest myrcene content (0.04%) and the mango variety with the highest myrcene content. In this case, the mango can triple the amount of myrcene ingested (to the equivalent of what you would ingest with a strain of cannabis of 0.12% myrcene).
However, Steep Hill Labs has indicated that you only start to see sedative properties when the myrcene content in cannabis goes above 0.5%. So it seems to me that most mangoes cannot add enough additional myrcene to have any effect.
Mango Beyond Myrcene
The myrcene found in cannabis is an important terpene that can act synergistically with THC to produce sedative and anxiolytic effects. However, if you want to maintain high energy, myrcene is not your friend.
This analysis makes it doubtful that the myrcene in mango really has an effect on how high you get. One of three things is possible:
- The Mango Theory is an Internet myth and anything that people feel with mango is a placebo
- Mango does have an effect, but only the few rare types that have a very high myrcene content
- Mango does have an effect, but it is due to another molecule besides myrcene
It’s not clear who originally thought that myrcene explained the effects of mango. There are other terpenes in mango that could also be involved. One example is terpinolene. Terpinolene is present at significantly higher levels than myrcene in most mango varieties and terpinolene has similar sedative properties.
There is only one thing I know for sure…a large portion of what you read about cannabis is based on myth more than it is based on science. That is why I am here to sort things out!
[Featured image credit: Flickr/ Nick Perla]
Last modified: July 3, 2017