If you're adding artificial sweeteners like aspartame into your coffee or tea, or sipping diet sodas to stay slim, you may not be doing your body any long-term favors.
Scientists have suspected for years that artificial sweeteners may stimulate our appetites and make us eat more. But a growing pile of research suggests that's not the only piece of bad news about fake sugar. Artificial sweeteners might be deadly.
A new study of more than 450,000 people across 10 European countries released Tuesday in the journal Jama Internal Medicine suggests that drinking two or more sweet-tasting beverages a day — whether they're filled with real sugar or imitation low- and no-calorie versions of sweetness — is linked with more early deaths, and more deadly heart issues. The finding held true even in people who maintained a healthy weight.
The new study doesn't prove that artificial sweeteners cause death. It could still be the case that people who are sipping more diet beverages tend to already be more at risk of dying for other reasons the researchers didn't assess.
Still, the study authors did try to control for several of the most common deadly health issues by excluding people who had cancer, diabetes, a history of strokes, or heart disease. While the researchers behind this new study believe theirs may be the largest artificial sweetener study of its kind, it isn't the first time research has suggested there may be something inherently dangerous for people about fake sugar.
Fake sugar changes the way that rat bodies operate
In a 2018 study, rats who were fed the common sweeteners aspartame and acesulfame K — found in products like Equal, NutraSweet, Sunett, and Sweet One — changed the way their bodies processed fat and energy. In the rats, this also led to muscle breakdown. The researchers behind that study think that the rats might've been tapping into their muscles as an alternative energy source, since the no-calorie sweeteners don't provide any nutrition.
The changes they saw in the rat bodies also appeared to set them up for developing chronic weight and sugar-processing problems, namely, diabetes and obesity. Those same mechanisms could be at work when humans drink fake sugar, though more research is needed to know for sure.
Brian Hoffmann, a biomedical engineer who studies high-sugar and high-sweetener diets at the joint Department of Biomedical Engineering at the Medical College of Wisconsin and Marquette University, first presented his rat research at the 2018 Experimental Biology conference.
"Non-caloric artificial sweeteners are foreign chemicals that your body does not have the machinery to deal with," Hoffmann said in a Q&A with Research Features. "Even those marketed as 'natural' because they are from a plant are foreign and it does not mean your body has the machinery to process them," he said.
But the International Sweeteners Association was quick to point out that his study didn't examine people.
"The ISA would like to highlight that this study does not provide evidence that low calorie sweeteners could adversely affect obesity or diabetes in humans," the trade organization told Business Insider in an email.
It's hard to prove definitively that artificial sweeteners cause health issues
The research to date on artificial sweeteners like aspartame has been conflicting and confusing. Some studies have suggested that zero-calorie sweeteners can help people lose weight, but even that research points out that reduced calorie beverages won't dampen your appetite. French scientists discovered a link between artificially sweetened beverages and higher rates of type 2 diabetes in 2013, but they were not positive the artificial sweeteners were actually causing the diabetes.
Potential problems with artificial sweeteners don't stop at the digestive tract. One small study of a dozen women at the University of California San Diego found that while artificial sweeteners taste sweet, they don't satisfy our brains in the same way as sugar.
Researchers who asked people to sip sugar water or sucralose (Splenda-sweetened) water noticed that only those who swallowed sugar activated the region of the brain associated with food rewards. That suggests zero calorie drinks may not satisfy the mind's craving for something sweet. Other studies in fruit flies have suggested that when we eat or drink artificial sweeteners, we are likely tricking our bodies into thinking we're starving. This could potentially make people eat more, too (that said, humans aren't fruit flies, so more evidence is needed).
While research on artificial sweeteners is still evolving, evidence about regular sugary beverages is more definitely damning. Sugary drinks are associated with a whole host of deadly health problems, and many nutrition experts still suggest that if you're drinking regular soda or sugary teas, switching to diet beverages can be a good strategy, at least temporarily, to curb sugar consumption.
"It is not as simple as 'stop using artificial sweeteners' being the key to solving overall health outcomes related to diabetes and obesity," Hoffmann said in a release. "As with other dietary components, I like to tell people moderation is the key if one finds it hard to completely cut something out of their diet," he said.
This story was originally published on May 2, 2018. It has been updated with the latest research.
