They may not be as harmful as some claim—but there’s still a very strong case for cutting them out of your diet.
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Artificial sweeteners are abundant in sugar-free beverages such as diet soda, fruit juices, and energy drinks, but they’re also used in processed foods such as candy, yogurt, bread, and even microwave popcorn. But how safe are they, and if you're cutting out sugar, are they a good replacement? We called on several experts to weigh in.

Also called high-intensity sweeteners, artificial sweeteners are used to sweeten many food and beverage products without increasing grams of sugar. The majority are "non-nutritive," meaning they flavor food without adding additional calories. They’re also much sweeter (sometimes hundreds of times sweeter) than table sugars such as granulated or brown sugar, and just a small amount can deliver an intense punch of sweetness to foods.  

The FDA has approved six high-intensity artificial sweeteners for use in food and beverage products: Saccharin, Aspartame, Acesulfame Potassium (Ace-K), Sucralose, Neotame, and Advantame. (Two additional high-intensity natural sweeteners—stevia and monk fruit—are considered Generally Recognized as Safe, or GRAS.) The FDA asserts, “High-intensity sweeteners, like all other ingredients added to food in the United States, must be safe for consumption.” The FDA also establishes Acceptable Daily Intakes (ADI’s) per kilogram of total body weight for each sweetener, which tell you exactly how much is safe to consume.

Originally, artificial sweeteners were intended for diabetics in need of a sugar-free option. As obesity rates in the U.S. increased, however, artificial sugar became an attractive, calorie-free substitute for anyone looking to lose weight while still drinking and eating sweetened foods.

In recent decades, certain studies have stirred controversy over artificial sweeteners by suggesting that they may cause cancer, type 2 diabetes, or a reverse effect from their intended use—weight gain. As a result, consumers have started to worry about the perceived health risks of artificial sweeteners.

While the FDA assures the safety of artificial sweeteners, could these studies suggest otherwise? Barry Popkin, PhD, distinguished professor of Nutrition at University of North Carolina at Chapel Hill, advises approaching studies about artificial sweeteners with a cautious eye.

“Many of the health claims against artificial sweeteners are supported by mice and rat studies,” says Popkin. “Per gram of body weight, mice are 100 times more sensitive to sweetness than humans. They can react very differently to the same substance, and you can’t rely on them to discuss the effect on humans.”

David Katz, MD, director of Yale University’s Yale-Griffin Prevention Research Center, agrees that most of these substances are unlikely to cause cancer. In an article for US News & World Report, he stated, “Artificial sweeteners are massively prevalent in our food supply...If artificial sweeteners were causing any meaningful, overt harm—the simple fact is, we would have seen it...In fact, over the decades that these chemicals have disseminated throughout our food supply, cancer rates have declined substantially.”

According to Popkin and Katz, it’s not the carcinogenicity of artificial sugar that we should be concerned about—it’s their potential to increase your threshold for sweetness, and what that could mean long-term for your health.

Because artificial sweeteners are much, much sweeter than sugar, consuming them frequently may alter the way you taste food. Long-term, you could find yourself needing to consume more sugar than before to satiate your sweet tooth.

We’re well aware that Americans are consuming way too much added sugar—which include artificial sugars, table sugar, honey, and more. We also know that eating too much added sugar spikes inflammation, which increases your risk for health problems such as weight gain and heart disease.

And as childhood obesity rates continue to rise, Popkin is particularly concerned about young children who consume high amounts of artificial sugar. “I do believe that preschoolers who are fed fruit juice or other sugary beverages and excessively sweet foods will have the potential to consume excessive amounts of sweet foods and beverages as teens and adults,” he says.

Does this mean that artificial sugars could be causing weight gain? According to Popkin, maybe, but more research is needed to prove it. However, Popkin does acknowledge a related problem—using artificial sweeteners as a means to rationalize eating otherwise high-calorie, unhealthy foods. “Drinking a zero-calorie Diet Coke doesn’t justify eating a Big Mac,” he asserts.

Credit: Photo: Jennifer Causey

Katz agrees—and for him, that’s reason enough to avoid artificial sweeteners entirely. “Artificial sweeteners are used routinely in products labeled 'diet,' implying we know these products help with weight loss. The simple fact is, reliance on them for help with weight loss is a leap of faith; and overt harms are a possibility."

When we asked Marion Nestle, Professor of Nutrition, Food Studies, and Public Health at New York University, and author of Why Calories Count: From Science to Politics for her opinion on artificial sugar, she provided a good guideline.

“One of my food rules is ‘never eat anything artificial.’ This keeps artificial sweeteners off my food radar, so I don’t have to worry about complications and controversies in the science.”

We couldn’t agree more with Nestle. If you’re looking to lose weight, the answer is probably not a can of diet soda. Stick to water, plain milk, and no-added sugar fruit juices—and instill lifelong healthy habits in your kids by encouraging them to do the same.

Avoid sneaky sources of added sugar in processed foods when possible and get your sweet fix from natural sugar sources such as whole fruit. Whether you fill your glass with fresh-squeezed fruit juices or pile your plate high with naturally-sweet blueberries, apples, oranges, bananas, and more, you’ll also benefit from the abundant health perks that come with these foods.