Sugar-free drinks may make sweet-detecting circuits numb to the real stuff
By baffling the brain, saccharin and other sugar-free sweeteners — key weapons in the war on obesity — may paradoxically foster overeating.
At some level, the brain can sense a difference between sugar and no-calorie sweeteners, several studies have demonstrated. Using brain imaging, San Diego researchers now show that the brain processes sweet flavors differently depending on whether a person regularly consumes diet soft drinks.
“This idea that there could be fundamental differences in how people respond to sweet tastes based on their experience with diet sodas is not something that has gotten much attention,” says Susan Swithers of Purdue University in West Lafayette, Ind. A key finding, she says: Brains of diet soda drinkers “don’t differentiate very well between sucrose and saccharin.”
Erin Green and Claire Murphy of the University of California, San Diego and San Diego State University recruited 24 healthy you