While this effect has been widely documented and popularized in drug culture, marijuana has long been a drug of interest for scientists looking for ways to stimulate or suppress appetite.
Researchers using genetically-modified mice pinpointed circuitry in the hypothalamus used by the active ingredient in cannabis to cause the “munchies.” They published their findings in a recent issue of Nature.
The team found that cannabinoids, an active ingredient of marijuana, work on a group of nerve cells called pro-opiomelanocortin neurons.
These neurons have, until now, been considered the big stoppers of over-eating, for they send out signals to say when satiety has been reached.
However, the neurons’ activity reversed when affected by cannabinoids, the active ingredient in marijuana. Instead of sending out a chemical that signaled the mouse was full, the cells sent out neurotransmitters called endorphins, known appetite-boosters.
The experiment allowed researchers to see what creates the hunger brought about by marijuana and how the mechanism that usually turns off the urge to eat instead creates the urge to feed.
“It was an interesting study,” said addiction specialist R. Corey Waller, MD, of the Spectrum Health Medical Group. “The cells identified in the study increased appetite by causing the stimulation of the endocannabinoid receptors CB1 and CB2. These are the fine-tuning receptors for appetite in the brain.”
Dr. Waller noted that some scientists view this study as laying the foundation for a drug that will help stimulate hunger in people who suffer from a loss of appetite, such as cancer patients.
Researchers still have a ways to go, he cautioned.
“Interestingly enough, the research shows that the appetite increase is specifically for carbohydrates, rather than food in general,” he said. “That’s why Cheetos and Doritos are on the top of snack lists for pot smokers. This also is why using it for increasing appetite in medical illness patients is no good. Their nutrition is still bad. Many carbs are just empty calories.”