The American Psychiatric Association doesn't recognize addictions to caffeine, artificial sweeteners, or diet soda—but plenty of people have tried, and failed, to give up these substances. So, can diet soda actually be addictive?
Writing for the New York Times, Abby Ellin highlights her own long-running relationship with Diet Coke and rounds up experts' opinions on whether drinking Diet Coke can truly be an addiction.
'[Quitting smoking] was easier than giving up Diet Coke'
Ellin writes that, for 39 years, she consumed three to four 12-ounce Diet Coke cans nearly every day. "At various times I tried to stop," she writes, "but I could never deprive myself for longer than a week."
Then, earlier this year, she began experiencing a sudden, throbbing pain in the left side of her abdomen. At the same time, her favorite drink to taste "like I imagine a Tide pod would," she writes.
CT scans, ultrasounds, and a colonoscopy didn't find anything wrong with her, but the experience finally motivated her to quit Diet Coke for good. She reports that, although she suffered from initial headaches from caffeine withdrawal, she is now experiencing less stomach pain.
Ellin is far from alone in struggling to give up the soda. Leatha Medina, a talent acquisition manager at Jewish Family Services in San Diego, founded a Facebook group called "Diet Soda Coke Drinkers Who WANT to Quit," which now has more than 1,100 members.
Medina started the group after realizing her own quests for Diet Coke were disrupting her schedule. "I was late to work because the line at McDonald's was too long," she said. "I started getting disgusted at how Diet Coke was kind of leading my life."
To wean herself off the beverage, Medina began asking McDonald's to fill her cup to the top with ice to dilute her Diet Coke. She experienced severe headaches when she quit, along with "hilariously PMS crankiness," she said. But gradually, she grew to like the watered-down version of Diet Coke, which helped her eventually give up the drink entirely.
Steven Walsh, an unemployed furniture mover in Kilkenny, Ireland, quit smoking 17 years ago, which he said, "was easier than giving up Diet Coke." In the weeks after he quit drinking the soda, Walsh also experienced headaches, tiredness, and irritability.
Some people need technological assistance to quit the drink. Mindy Beller, a technical editor for an environmental consulting company in North Carolina, tried to stop drinking her usual eight daily cans of Coke Zero after an unsuccessful breast cancer surgery. Beller used an app called Quitzilla to track her progress. She didn't have many physical side effects, but she did crave the drink and credits the app with keeping her on track.
So, are diet sodas clinically addictive?
Ashley Gearhardt, an associate professor in the department of psychology at the University of Michigan and the director of the school's Food and Addiction Science and Treatment Lab, said some of the side effects people experience after quitting diet soda are classic signs of addiction.
"People lose control over it. They consume it even though they know they should stop. They're having compulsive behaviors. They go through withdrawal when it gets removed," she said. "If Diet Coke—or any diet soda—was a new pharmaceutical product and we were testing it for whether people are getting addicted to it, we would be very concerned."
Gearhardt claims that diet sodas' caffeine and aspartame make them difficult to quit.
According to Coca-Cola, a 12-ounce can of regular Coke has 34 milligrams of caffeine, whereas Diet Coke has 45. (By comparison, an eight-ounce cup of coffee has about 95 milligrams of caffeine.)
Pamela Peeke, an assistant professor at the University of Maryland and author of "The Hunger Fix," said artificial sweeteners activate the brain's reward system by only about half as much as sugar, leaving consumers wanting more.
And at least in animals, artificial sweeteners can be a powerful temptation. A 2007 study found that when laboratory rats were forced to choose between saccharin (a noncaloric sweetener) and cocaine, 94% of the rats chose saccharin, even if they had previously shown signs of cocaine dependence.
Research in humans has produced mixed results on whether artificial sweeteners or the other ingredients in diet sodas have adverse health effects. Some studies have linked the beverages to symptoms as diverse as tooth decay, diabetes, diarrhea, and strokes, Ellin writes—although other analyses of artificial sweeteners have failed to identify any clear negative health impacts.
For its part, Coca-Cola suggested that Diet Coke is simply pleasurable to drink. "Food and beverages, like chocolate, for example, can trigger what scientists call 'reward centers' in the brain, but so can other things like music or laughter," Daphne Dickerson, a spokesperson for Coca-Cola, said.
Dickerson argued, "Regularly consuming food and beverages that taste good and that you enjoy is not the same as being addicted to them." (Ellin, New York Times, 8/11)