Forget What You Heard: Experts Say Artificial Sweeteners Are Safe

We asked the experts, and they said the idea that artificial sweeteners cause cancer is just a myth.

Sugar packets

Sugar packets photo via Shutterstock

Artificial sweeteners present a conundrum for many people. They cut calories and sugar intake, but attention-grabbing articles come out with some frequency linking them to cancer and other heath problems. It’s enough to turn your morning coffee order from a simple task to an indecision-riddled dilemma—but experts say it doesn’t have to.

Caroline Apovian, director of the Nutrition and Weight Management Center at Boston Medical Center and a professor at Boston University Medical School, says that, despite what you may have heard, no concrete research has shown a link between artificial sweeteners and human cancer. “The National Cancer Institute has weighed in on this,” Apovian says. “There is no scientific evidence that any of the artificial sweeteners approved in the United States cause cancer in humans.”

Apovian says many people associate artificial sweeteners with cancer because of studies that took place in the 1970s linking sweeteners with bladder cancer in male rats, studies that Apovian says shed little light on their effect on humans and were conducted using extremely high doses of the substances. “Sometimes you can use animal studies to extrapolate what happens in humans, but you have to know the model you’re using,” she explains. “Male rats had a higher risk of developing bladder cancer than humans anyway, but people still have in mind, all these years later, that artificial sweeteners cause cancer.”

The only proven negative side effects of sweeteners, Apovian says, are minor things like headaches brought on by too much aspartame and bloating and diarrhea in people who are sensitive to sugar alcohols, but that people who experience these conditions generally know and simply avoid sweeteners.

Deborah Krivitsky, a registered dietician in the Massachusetts General Hospital Cardiovascular Disease Prevention Center, agrees that sweeteners are safe in moderation, though she did note the lack of long-term studies about sweeteners as something to be mindful of. “The bottom line is use them in moderation, but they definitely have a place,” she says, adding that her favorite is Splenda. “If you’re having a diet soda or two a day, I think you’re okay.”

In the absence of evidence linking sweeteners to health risks, Krivitsky says they’re actually a good thing since they help regulate weight. “They don’t raise blood sugar, they don’t add calories,” she notes. Perhaps more importantly, Krivitsky says, artificial sweeteners prevent people from eating sugar, which she classifies as a dangerous substance. Krivitsky explains that consuming a lot of sugar causes a spike in insulin production, the hormone responsible for clearing sugar from the bloodstream, which in turn leads to inflammation. “When [inflammatory markers] are elevated, they’re associated with poor outcomes for heart disease, for diabetes, and for cancer as well,” she says. “So these sugars, we used to call them empty calories because we said they taste good but they don’t give you a lot of nutrition. It’s actually not the truth. Now we understand these sugars are actually toxic.”

Apovian also says artificial sweeteners are a better option than consuming lots of natural sugar. “If you’re talking about one teaspoon of sugar a day versus one packet of artificial sweeteners, I don’t think it makes a difference,” she says. “When you’re starting to take in 10 or 15 [teaspoons of sugar] a day, go to the artificial sweetener.”

An even better strategy? Move away from highly-sweetened foods in the first place. “We have an obesity epidemic and a diabetes epidemic in this country,” Krivitsky says. “We really need to move away from processed foods.”