Can You Get Hooked on Diet Soda?
Diet soda isn't as addictive as drugs like nicotine, but something about it seems to make some people psychologicallyand even physicallydependent on it
Similarly, people may get hooked on diet soda because they associate it with a certain activity or behavior, as Bagi did with smoking. "You can get into a situation where you crave a diet soda by conditioning yourself," Dr. Urschel says. "[If] you stop for gas and always get a diet soda, the craving will start to come first, before you even pull into the station."
The psychological components of diet-soda cravings are powerful, but they aren't the whole story. Research suggests that the artificial sweeteners in diet soda (such as aspartame) may prompt people to keep refilling their glass because these fake sugars don't satisfy like the real thing.
In a 2008 study, for instance, women who drank water that was alternately sweetened with sugar and Splenda couldn't tell the differencebut their brains could. Functional MRI (fMRI) brain scans revealed that even though both drinks lit up the brain's reward system, the sugar did so more completely.
"Your senses tell you there's something sweet that you're tasting, but your brain tells you, 'Actually, it's not as much of a reward as I expected,'" says Martin P. Paulus, MD, a professor of psychiatry at the University of California San Diego, and one of the authors of the study. "The consequence might be that the brain says, 'Well, I'll have more of this.'"
In other words, artificial sweeteners may spur drinkersor their brainsto keep chasing a "high" that diet soda keeps forever just out of reach. It's not clear that this teasing effect can lead to dependence, but it's a possibility, Dr. Paulus says. "Artificial sweeteners have positive reinforcing effectsmeaning humans will work for it, like for other foods, alcohol, and even drugs of abuse," he says. "Whenever you have that, there is a potential that a subgroup of people...will have a chance of getting addicted."
Timothy S. Harlan, MD, a nutrition specialist and assistant professor of internal medicine at the Tulane University School of Medicine in New Orleans, says that while diet-soda dependence appears to be a real phenomenon, it is probably caused by a complex mix of behavioral factors, not necessarily artificial sweeteners. "I don't think there is clear-cut evidence of biochemical dependence on diet soda, but my sense is that certainly people do become habituated to diet soda and dependent upon it," he says.