The Truth

about Diet Soda

For years, experts have wondered whether drinking too much diet soda can cause diabetes—in fact, it’s a question that both studies and scientists themselves could never seem to solve. But now, we may finally have a definitive answer.

Drinking diet soda is not associated with type 2 diabetes—at least, not if you account for the person’s other health factors, according to a new study in the American Journal of Clinical Nutrition. On the other hand, this research also found that consuming regular, sugary soft drinks is linked to the condition. (Yep, it seems as if there’s no getting out of that one . . .)

Lawrence de Koning, Ph.D., a research fellow at Harvard School of Public Health, says that his colleagues and he were puzzled by the theory. After years of watching studies find an association between diet beverages and diabetes, they finally decided to do some research of their own.

After all, he says, it made perfect sense that sugar-sweetened drinks could hurt your health—the frequent sugar rushes could cause insulin resistance over time—but it made no sense how drinks without sugar could also be linked to diabetes. (Of course, some drinks are better options than others. Click here to view The Best and Worst Soft Drinks in America).

So de Koning and his colleagues took data from a 20-year-long study of more than 40,000 men from the Boston area, which tracked each subject’s eating, drinking, and health habits. At the end of the study, 2,680 of the men had been diagnosed with the disease.

The researchers found that with each daily serving of a sugar-sweetened beverage—a can of regular soda, for example—their diabetes risk rose by 16 percent. And, in fact, on first glance, it looked like the people who quaffed diet drinks also showed a risk for diabetes.

However, when the researchers looked at each person’s health conditions a little more closely—such as examining their BMI levels, dieting history, high triglycerides, high blood pressure, and family history—they discovered that there was no link at all between diet sodas and diabetes.

One reason: de Koning and his colleagues suggest that many people who chose diet drinks might be trying to make a change because they’re already in poor health.

“It’s all in the name on the label,” he says. “People drinking diet soda might be dieting because they know they’re already at an increased risk for health problems.”

So what about the idea that sugary drinks just make you crave more of the sweet stuff? Scientists have never actually proven that, says de Koning. It’s just one theory for why diet beverages were linked to diabetes. (Keep in mind, de Koning’s research doesn’t disprove this mechanism either.)

An even better choice than diet soda? Coffee, says de Koning. In the study, each daily cup of coffee was associated with a 17 percent lower risk of diabetes.

For more drinks to avoid, study up on The Worst “Health” Drinks in America.