Diet Soda Could Actually Be Worse For You Than The Regular Stuff

Diet sodas may be calorie-free, but they could be worse for your health and your waistline than ones with sugar, a new report suggests. Over the long term, fake sweeteners like aspartame, sucralose, and saccharine might mess with our bodies' abilities to process the calories from sweet things, making it harder for us to metabolize the sugars we get from other sources like candy, cookies, or even fruit.

Purdue University scientist Susan Swithers found in a meta-analysis of 26 health and diet studies that artificially-sweetened sodas — unlike water — were often still associated with many of the same ailments common in people who drink sugary sodas, and may actually increase the risk of obesity, metabolic syndrome and Type 2 Diabetes.

We first heard about Swithers' analysis via NPR. She discussed the results in an an opinion piece published in the July 10 issue of the journal Trends in Endocrinology and Metabolism.
According to Swithers, the trouble with artificial sweeteners is the same thing that makes them so popular — they taste a lot like sugar and have few or zero calories. For example, the molecule for sucralose (found in products like Splenda), is extremely similar to the molecule for sugar. That is why it tastes eerily similar — it is tricking our bodies into thinking we are eating something sugary.

But our bodies cannot metabolize sucralose. It just passes through us. This is its charm— and its potential danger. Normally, when our body detects that we have eaten something sweet, it anticipates the arrival of much needed energy and activates mechanisms to capture it. If we continuously fool the body with sweet tastes that do not bring any energy or nutrients, we risk teaching our own metabolisms to stop responding to sweet tastes entirely. We are essentially "crying wolf," and when we finally do eat something with sugar, the body ignores the signal and fails to process it properly.

Over time, whatever calories people think they are cutting with artificial sweeteners might just be returning to them in the form of poorly metabolized sugars from other foods.

The data Swithers examines does not establish a direct cause-and-effect relationship between sweeteners and obesity, it simply sees a strong correlation — just as strong as we see with regular soda. There could be other explanations.

For example, it may be that using artificial sweeteners changes people's behavior in other ways — some might think because they are drinking a "diet" soda, they can afford to eat an extra helping of French fries. In any event, the data does indicates that fake sweeteners are not helping people lose weight, and should not be treated as a totally safe and neutral alternative to sugary drinks.

"Findings from a variety of studies show that routine consumption of diet sodas, even one per day, can be connected to higher likelihood of heart disease, stroke, diabetes, metabolic syndrome and high blood pressure, in addition to contributing to weight gain," Swithers said in a press release.

The trend was consistent in virtually every study Swithers examined, even though each used different research methods, examined different populations of people, and had different ways of accounting for factors like ethnicity, education level and other dietary habits.

Of course, the American Beverage Association has already offered rebuttals to news outlets NPR and USA Today, which includes the statement,

"Low-calorie sweeteners are some of the most studied and reviewed ingredients in the food supply today. They are safe and an effective tool in weight loss and weight management, according to decades of scientific research and regulatory agencies around the globe."