You know that routinely guzzling sugary drinks and scarfing down sweets is not a healthy habit. Doing so can lead to weight gain, type 2 diabetes, heart disease and other serious diseases and complications.
But is replacing all that added sugar with low- and no-calorie sweeteners any healthier? That’s a question of ongoing debate.
Most recently, on July 13, an agency within the World Health Organization (WHO) named the widely used artificial sweetener aspartame a possible cause of cancer, citing limited evidence of an increased risk for liver cancer in humans. A review by a second group within WHO found the evidence less convincing, however, and said the data “indicated no sufficient reason to change the previously established acceptable daily intake” of aspartame. The group said an adult weighing approximately 150 pounds would need to drink, for example, between nine and 14 cans of diet soda a day to exceed that limit.
“The assessments of aspartame have indicated that, while safety is not a major concern at the doses which are commonly used, potential effects have been described that need to be investigated by more and better studies,” Francesco Branca, director of WHO’s Department of Nutrition and Food Safety, said in a statement.
Aspartame has been at the center of the sweetener controversy for decades. In addition to possible cancer risk, other studies have linked it to potential health concerns, including cardiovascular disease and disruptions in the gut microbiome, a community of microorganisms that live in the digestive tract and help the body carry out various functions.
Still, the U.S. Food and Drug Administration (FDA), which approved aspartame in 1974 and has studied it since, maintains that the sweetener is safe when “used under the approved conditions.” The FDA responded in disagreement to the WHO group’s assessment, adding that it reviewed the same studies used in the evaluation and “identified significant shortcomings” in the research.
Other sweeteners under scrutiny
A study published this year in the journal Nature Medicine found a link between the sweetener erythritol and an increased risk of heart attack and stroke. Erythritol is a common sugar replacement found in many products marketed for the popular low-carb keto diet. Low amounts occur naturally in some fruits and vegetables; the body also produces low levels of erythritol to aid in energy metabolism. When used as a sweetener, however, erythritol levels are typically 1,000 times greater than levels found naturally in foods, according to a summary of the research from the National Institutes of Health.
For the study, a team of researchers from the Cleveland Clinic looked at levels of erythritol in the blood of more than 4,000 adults who were already at higher risk for cardiovascular diseases. What they found was that people with the highest levels of erythritol in their blood were more likely to have a heart attack or stroke.
A few other findings to note: When the researchers mixed erythritol with blood samples from healthy individuals, the blood platelets were more likely to clot, which can increase risk for heart attack and stroke. And when a small group of healthy individuals drank a beverage sweetened with the compound, the levels of erythritol in their blood increased 1,000-fold and remained elevated for several days.
Senior study author Stanley Hazen, M.D., points out that “the very people who are most vulnerable to heart disease” — people with type 2 diabetes or obesity, for example — are the ones who are more likely to be targeted with foods sweetened with no-calorie sugar substitutes, also called nonnutritive sweeteners.
“And yet, by trying to [make a healthy choice], they may inadvertently be contributing to heightened risk,” says Hazen, chairman for the Department of Cardiovascular and Metabolic Sciences at the Lerner Research Institute and co-section head of preventive cardiology at the Cleveland Clinic. He emphasizes that more research is needed to better understand the potential risk.