Diet Soda Linked to Obesity and Heart Disease


You may want to exert caution the next time you search the fridge for a refreshing beverage. That diet soda you’re eyeing may not be good for your long-term health.

A new study found that artificial sweeteners, such as aspartame, stevia and sucralose, are linked to a wide range of negative health outcomes over the long term, including weight gain, heart disease, high blood pressure and diabetes.

Credit: Phera Laster/Flickr, CC BY 2.0

Such non-nutritive artificial sweeteners are found in many beverages, from diet sodas to flavored seltzer waters, and they are often touted as a healthy part of a weight-loss plan or low-calorie lifestyle.

However, after reviewing 37 studies that tracked the health patterns of more than 400,000 people, researchers from the University of Manitoba found a set of cautionary associations that may cast artificially sweetened beverages under a new light.

For one, the researchers found no link between the consumption of artificially sweetened beverages and long-term weight loss. Conversely, they discovered that “routine intake of nonnutritive sweeteners may be associated with increased [body mass index] and cardiometabolic risk,” as they report in the Canadian Medical Association Journal.

While suggesting further research is needed, the new findings should give consumers pause before they reach for a diet soda as part of their weight-loss plan.

“Caution is warranted until the long-term health effects of artificial sweeteners are fully characterized,” said lead author Dr. Meghan Azad, assistant professor at the Rady Faculty of Health Sciences, University of Manitoba.

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“Given the widespread and increasing use of artificial sweeteners, and the current epidemic of obesity and related diseases, more research is needed to determine the long-term risks and benefits of these products,” said Azad.

As the link to weight gain and other negative health outcomes comes under scrutiny, so too does the perception that diet drinks are a safe alternative to sugar-filled beverages when it comes to a healthy lifestyle and maintaining a healthy weight.

“We found that data from clinical trials do not clearly support the intended benefits of artificial sweeteners for weight management,” said study author Dr. Ryan Zarychanski, assistant professor at the Rady Faculty of Health Sciences, University of Manitoba.

However, the specific ties between diet drinks and weight gain, as well as heart disease and other negative health outcomes, remain somewhat elusive.

Related: The Bittersweet Truth About Sugar Substitutes

“Despite the fact that millions of individuals routinely consume artificial sweeteners, relatively few patients have been included in clinical trials of these products,” said Zarychanski.

The researchers speculate that artificially sweetened products may still trigger a physical response within the body that alters a normal metabolic process, or that people assume that consuming non-nutritive sweeteners allows them to eat other calorie-rich foods.

While the medical community seeks further answers, at least one researcher is putting the new findings to use.

“I think there’s enough association and questions out there that it made me rethink what I do on a daily basis,” Azad told the Washington Post. “I used to sweeten my coffee with Stevia in the morning and when I wanted a fizzy drink, I’d get a Diet Coke. Now I just use milk and I drink sparkling water.”