Yale Scientists May Have Figured Out Why Pot Causes the Munchies

(Bloomberg Business) -- Using marijuana on a full stomach might still cause the munchies, flipping a switch in the brain that usually tells the body it’s not hungry, a study found.

The findings were the opposite of what researchers said they expected—the neurons should have been turned off since the mice in the study had just eaten, said senior study author Tamas Horvath. The paper appeared Wednesday in the journal Nature.

“The brake becomes the gas pedal. All of a sudden it becomes the exact opposite of what it’s supposed to do normally,” said Horvath, a professor of biomedical research and comparative medicine at Yale University School of Medicine in New Haven, Connecticut. “It fools the brain’s central feeding system.”

The findings are the first to show how marijuana may work in the brain to cause the munchies, Horvath said. The results may provide a way to help cancer patients who lose their appetite during treatment, he said.

The researchers used mice to monitor the action of cannabinoid, a key component of marijuana, on the brain circuitry that promotes eating. The mice were injected with a synthetic form of cannabinoids after being fed. The researchers then looked at brain samples to determine what and how neurons were affected by the drug, Horvath said.

More research is needed to replicate these findings and to see if the neurons play a role in the “high” from marijuana as well. Still, Horvath expects the results to hold true in humans.

“Anyone who ever smoked and had the munchies will understand,” he said.