Gila monster saliva: the new appetite suppressant?

Who would have thought that a little lizard spit could help dieters with self-control?

One of the most challenging aspects of dieting is self-control—you simply want what you can’t have. But new evidence out of Sweden suggests a way around that. A substance called exendin-4, which is a peptide found—oddly enough—in the saliva of North America’s only venomous lizard, the Gila monster, may be able to stop those pesky cravings for snacks both savoury and sweet.

Researchers at the University of Gothenburg’s Sahlgrenska Academy decided to look into exendin-4 after they noticed patients receiving it for treatment of Type 2 diabetes tended to lose weight (previous research had shown it helped control blood-sugar levels). Working with lab rats, assistant professor Karolina Skibicka and her colleagues found exendin-4 effectively dispelled rodents’ cravings for chocolate and sugar. Given the mechanism that causes cravings—the release of dopamine in the brain—is the same in rats and humans, their hope is that exendin-4 can be used to chemically reduce the urge to overeat. “With the Western world obesity epidemic ballooning, any help to reduce food intake and body weight can have enormous health potential,” says Skibicka.

The results of their study, published in the Journal of Neuroscience, have caused speculation that the substance might also hamper alcohol addiction, since the dopamine circuitry of the brain is also involved in the desire to drink.