Studies show that worms can also get the munchies from cannabis

It’s a well-known fact that cannabis use often leads to cravings, leading consumers to eat more and crave tasty, high-calorie foods. Now, a new study published in the journal Current Biology has found that cannabinoids can also cause worms — particularly nematodes (C. elegans) — to crave.

“Cannabinoids make nematodes more hungry for their preferred food and less hungry for their non-preferred food,” Shawn Lockery, study co-author, said in a press release. “Thus, the effects of cannabinoids in nematodes resemble the effects of marijuana on human appetite.”

Lockery added that nematodes diverged from the lineage that led to mammals more than 500 million years ago, calling it “truly remarkable” that the effects of cannabinoids on appetite have persisted through this evolutionary span.

The study was originally inspired by Oregon’s legalization of cannabis in 2015. Lockery said her lab was studying nematode food preferences in the context of researching the neural basis of economic decision-making when they decided to investigate whether cannabinoids would alter their preferences.

Nematodes also look a lot more like humans than many other species at the molecular level, researchers note, raising the question of whether the feeding effects of cannabinoids would persist across species.

Cannabinoids bind to cannabinoid receptor proteins in the brain, nervous system and other parts of the body, researchers explain. These receptors respond to endocannabinoids, which are molecules already present in the body. The endocannabinoid system is known to play a crucial role in a number of bodily functions such as eating, learning, memory, reproduction and more.

The researchers showed that worms exposed to anandamide, an endocannabinoid, ate more of their favorite food, with the effect depending on the presence of the worms’ cannabinoid receptors.

In further studies, researchers genetically replaced the nematode cannabinoid receptor with the human cannabinoid receptor and found that animals responded normally to cannabinoids. The researchers said this discovery underscores the commonality of cannabinoid effects in nematodes and humans, adding that anandamide’s effects depend on neurons involved in food recognition.

The study concluded, “In mammals, administration of THC or endocannabinoids induces hedonic food intake,” specifically citing that anandamide has been shown to alter food intake and “differentially alter appetite behavior.”

Lockery elaborated, explaining that the sensitivity of one of the key olfactory neurons in nematodes that detect food is “dramatically altered” by cannabinoids. He explained that once exposed to cannabinoids, the worm becomes more sensitive to preferred food odors and less sensitive to unwanted odors.

“This effect helps explain changes in the worm’s food intake and is reminiscent of how THC makes palatable food even tastier in humans,” Lockery said.

Of course, it’s just fun to know that worms can have an experience similar to a human swallowing a bag of Cheetos after smoking a blunt, but Lockery explained how these findings have meaningful, practical applications.

“Cannabinoid signaling is present in most tissues in our body,” he said. “Therefore, it could be involved in the cause and treatment of a variety of diseases. The fact that the human cannabinoid receptor gene is functional in C. elegans food choice experiments sets the stage for a rapid and inexpensive screening for drugs that target a variety of proteins involved in cannabinoid signaling and cannabinoid signaling -metabolism, with profound implications for human health.”

There are still a number of unanswered questions on this topic, namely how cannabinoids alter the sensitivity of olfactory neurons in nematodes that lack cannabinoid receptors. The researchers were also curious to study how psychedelics interact with nematodes in the future.