Have you ever wondered why smoking marijuana can lead to a massive case of the munchies? If so, you are not alone. Researchers have long questioned the exact mechanism that creates an appetite in those who use cannabis.
Now, it seems we may at last have a definitive answer that can explain the enhanced flavors, scents, as well as increased cravings for food that cannabis users report after lighting up.
According to a study published in Nature Neuroscience, mice who were given tetrahydrocannabinol (THC), one of the main, naturally occurring chemicals found in cannabis, demonstrated an increased sensitivity in the olfactory bulb area of their brains.
Smell in Rats and Humans
This area, in both humans and mice, is responsible for regulating the sense of smell, and processing the information of scents. (It also aids in the intensity of flavors and tastes.) In rats, the olfactory bulb is studded with over 2,000 small structures called receptors. This gives them an exquisitely sensitive sense of smell.
When the rats ingested THC, they were able to more easily detect and locate food because that section of their brain basically lit up with the neurological equivalent of a Fourth of July fireworks show, allowing them to smell and taste with greater sensitivity.
In fact, not only were they able to distinguish more smells, they continued to do so for longer periods of time. This may not seem significant, but it is actually one of the main reasons that researchers concluded that both humans and rats get the munchies from cannabis use.
THC Changes the Way Food Tastes and Smells
Normally, when rats, or humans for that matter, encounter an odor, the ability to detect it lessons over time. In other words, we tend to be come nose-blind to odors the longer we are around them.
And because much of our sense of taste is linked to smell, we tend to lose the taste for something as we consume it. This helps us feel less inclined to continue eating past the point of satiety. While this is a powerful motivator to eat, in and of itself, other chemicals work to increase appetite by sending what amounts to a starvation signal so that your body feels incredibly motivated to eat.
In a study published in Behavioral Neuroscience, researchers at the National Institute of Health also concluded that THC hijacks the brain by overriding a specific brain region located in the hypothalamus. Known as the POMC cluster, this area is dedicated to mood levels, emotions, sex drive, appetite, feeding and alertness.
The POMC cluster is the one that sends out the signal to stop eating. In the case of cannabis however, the signal becomes scrambled so that instead of switching off, the switch gets stuck in the on position.
Without the normal stop sign, your body keeps trying to push you to feed. (Lab rats in which the POMC center is damaged will eat until they are morbidly obese.)
This makes it easy to understand why the THC in cannabis packs such a punch. It prolongs the yummy smell/taste, prevents brain from sending the signal to stop eating and adds a veritable cocktail of happy brain chemicals known as endorphins that make you feel good while you eat.
This is why you are able to distinguish scents, flavors and tastes more clearly and for longer than you normally would. Plus, your brain is basically doing the happy dance and telling you that you need to eat more and more. No wonder that cannabis users experience a massive case of the munchies.
This post was originally published on February 3, 2016, it was updated on March 15, 2017.