The munchies are weird, aren’t they? You can be full, having just eaten a big dinner, and then poof, 15 minutes later you’re ravenous, even though you know it can’t possibly be true. But your brain seems absolutely certain that it wants — no, that it needs — those chips, that cheese, just a few scoops of ice cream (the munchies never make us hungry for carrots and celery). So what’s going on here? Why or how does marijuana consumption create some kind of weird disconnect between our brains and our stomachs? Scientists have asked the same questions (inquiring minds want to know, after all), and after conducting research, they now think the munchies aren’t just due to cannabinoid receptors, they’re also a result of a heightened sense of smell.
French researchers published their findings in Nature Neuroscience, earning that magazine more street cred that it ever thought possible. The researchers started with the already-proven premise that THC binds to the brain’s cannabinoid receptors, which blocks neurological signals of satiation. That’s why we don’t feel full even though we should, but that doesn’t necessarily explain why we feel actively hungry. So the researchers focused on those cannabinoid receptors and how they affect our other senses, namely smell.
The researchers studied mice, comparing how much hungry but sober mice ate with how much hungry and THC-injected mice ate. The latter group chowed down way more, but when their cannabinoid receptors were deactivated, the THC injections didn’t affect how much they ate at all. The THC-injected mice also demonstrated enhanced olfactory abilities — when the researchers subjected them to smells of banana and almond oil, they responded more dramatically, even when the smells were fainter. The THC essentially gave them super sniffing powers. And when one has a keen sense of smell, one gets hungry, no matter what the stomach (or brain) says.
The study has some potentially interesting implications when it comes to treatment for eating disorders. Marijuana has long been used to stimulate the appetites of people suffering from diseases such as cancer, and researchers think they may be able to develop a drug that would help enhance the cannabinoid signals, making THC even more effective for appetite enhancement. A similar approach could be used for patients suffering from anorexia. On the flip side, the study presents some possibilities for treating obesity — if the cannabinoid signals could be interrupted or blocked, that could decrease one’s feelings of hunger. A similar approach was taken by Sanofi-Aventis back in 2006 when it developed a drug that blocked cannabinoids, but the negative side effects were dramatic enough to cause them to pull it off the market. Refining that approach with the new information could prove successful, though. It seems like pretty good timing, especially given that medical marijuana dispensaries will soon be popping up in my state.
If the scientists need any human volunteers, my receptors are ready.