Why chocolates are better munchies than carrots: endocannabinoids boost sweet taste

(E Science News) New findings from the Monell Center and Kyushu University in Japan report that endocannabinoids act directly on taste receptors on the tongue to enhance sweet taste. “Our taste cells may be more involved in regulating our appetites than we had previously known,” said study author Robert Margolskee, M.D., Ph.D., a Monell molecular biologist. “Better understanding of the driving forces for eating and overeating could lead to interventions to stem the burgeoning rise in obesity and related diseases.”

Endocannabinoids are substances similar to THC, the active ingredient in marijuana. Produced in the brain and body, they bind with cannabinoid receptors to help regulate appetite and many other processes involved in health and disease.

“Endocannabinoids both act in the brain to increase appetite and also modulate taste receptors on the tongue to increase the response to sweets,” said study senior author Yuzo Ninomiya, Ph.D., Professor of Oral Neuroscience in the Graduate School of Dental Sciences at Kyushu University in Japan.

In the study, published online in the Proceedings of the National Academy of Sciences, the researchers conducted a series of experiments in mice to determine the behavioral, neural and cellular responses to sweet taste stimuli before and after the administration of endocannabinoids.

Sweet taste responses were enhanced by endocannabinoids in every case. The effect was specific for sweet taste, as endocannibinoids had no effect on responses to sour, salty, bitter or umami taste stimuli.

Now think about this in an evolutionary context.  Think of primitive humans, struggling to survive, with many choices of foods out there, but the sweet foods, the fruits and berries, are high in the calories and vitamins we need to survive.  Then there is this plant, this weed, struggling to survive, which happens to make a molecule that binds perfectly with the receptors that make primitive humans prefer berries over other foods.  The primitive humans who eat the weed then eat the berries, eliminating seeds (plus fertilizer), and survive longer than the non-fruit-and-berry-eating humans.  Plus that weed provides pain relief, restful sleep, and the occasional spiritual vision for those primitive humans, who would eventually figure out tools and make other, non-edible uses for that weed.

I don’t think it is too far off to say that cannabis and humans co-evolved in a complimentary relationship and neither would be here today without the other.  This plant survived by stimulating our brains and our appetites and we returned the favor by cultivating this plant.  If dogs hadn’t already taken the title, cannabis would be man’s best friend!