The ‘weed munchies’ are synonymous with getting high: you smoke, then you get an insatiable hunger and eat every bag of Doritos in sight. People have always assumed the weed munchies are real, but somehow controllable, and more psychological than neurological. Well it’s time we all readjusted our thinking, because a team of neuroscientists just discovered a neurological breakthrough suggesting that the munchies are caused by the disruption of POMC neurons by cannabinoids….So it’s cool if you get the munchies and can’t stop eating, it’s not on you, it’s your body that can’t stop, not your brain.
Recreational weed usage is flourishing across the nation, and though it’s one of the most researched topics of the past half century I suspect we’re going to see a massive spike in the level of studies being conducted as pot becomes more prevalent and less taboo.
This particular study was published on Nature.com and titled ‘Hypothalamic POMC neurons promote cannabinoid-induced feeding’…But what does that all mean? If you’re a higher-education degree-holding scientist, maybe you can decipher this excerpt…If not, I suggest you skip below where we break it down in layman’s terms:
Here we test whether CB1R-controlled feeding in sated mice is paralleled by decreased activity of POMC neurons. We show that chemical promotion of CB1R activity increases feeding, and notably, CB1R activation also promotes neuronal activity of POMC cells. This paradoxical increase in POMC activity was crucial for CB1R-induced feeding, because designer-receptors-exclusively-activated-by-designer-drugs (DREADD)-mediated inhibition of POMC neurons diminishes, whereas DREADD-mediated activation of POMC neurons enhances CB1R-driven feeding. The Pomc gene encodes both the anorexigenic peptide α-melanocyte-stimulating hormone, and the opioid peptide β-endorphin. CB1R activation selectively increases β-endorphin but not α-melanocyte-stimulating hormone release in the hypothalamus, and systemic or hypothalamic administration of the opioid receptor antagonist naloxone blocks acute CB1R-induced feeding. These processes involve mitochondrial adaptations that, when blocked, abolish CB1R-induced cellular responses and feeding. Together, these results uncover a previously unsuspected role of POMC neurons in the promotion of feeding by cannabinoids.
So what does all that mean? According to NPR it means Cannabis has a paradoxical effect on your brain’s natural inclination to shut down obesity. From NPR’s Angus Chen:
Researchers have been probing different parts of the brain looking for the root cause of the marijuana munchies for years. Now, a team of neuroscientists report that they have stumbled onto a major clue buried in a cluster of neurons they thought was responsible for making you feel full.
This cluster, called the POMC neurons, is in the hypothalamus, a region of the brain that scientists typically associate with base instincts like sexual arousal, alertness and feeding. Tamas Horvath, a neuroscientist at the Yale School of Medicine and the team’s leader, says that the POMC neurons normally work by sending out a chemical signal telling the brain, you’re sated, stop eating.
In the past, when neuroscientists shut down POMC neurons in mice, all the mice became morbidly obese. Horvath figured that in order for the drug in marijuana — compounds called cannabinoids — to spawn that undeniable impulse to feed, it would have to bind the activity of these neurons and make them fire less. Paradoxically, Horvath says, “We found the exact opposite.”
The team discovered that when they injected cannabinoids into mice, the drug was turning off adjacent cells that normally command the POMC neurons to slow down. As a result, the POMC neurons’ activity leapt up. At the same time, the cannabinoids activate a receptor inside the POMC neuron that causes the cell to switch from making a chemical signal telling the brain you’re full to making endorphins, a neurotransmitter that’s known to increase appetite.
These two effects combined create a kind of runaway hungry effect. “Even if you just had dinner and you smoke the pot, all of a sudden these neurons that told you to stop eating become the drivers of hunger,” Horvath says. It’s a bit like slamming down on the brakes and finding weed has turned it into another gas pedal.
Still confused? Sharon Begley from Reuters reports:
“Neurons that normally shut down eating instead promoted it, even when the mice were full,” Horvath said in an interview. “Marijuana fools the brain’s feeding system.”
It does not fool the brain into eating just anything, however. Smoking marijuana rarely leads to a craving for broccoli. Instead, he said, the brain mechanisms create a desire for calorie-dense foods like salty, fatty chips and rich sweets.
There are likely additional brain pathways by which marijuana causes the munchies, which could be tapped for one of the drug’s medical uses: increasing appetite in cancer patients and others who have lost the desire to eat.
If you’ve come this far and still don’t understand, you can either read the study in full, or you can just accept that ‘The Munchies’ are a scientifically proven phenomenon, though I had to italicize ‘proven’ because more research is still required to actually prove this.
Just know that you can absolve yourself of guilt next time you get the munchies and give in to your body’s urge to gorge itself on any food in sight.