Will Synthetic Sweeteners Be Next for U.S. Ingredient Bans?

The FDA doesn’t agree with WHO’s 2023 ruling, and the U.S. agency continues to permit the use of aspartame in more than 2,500 grocery store and pharmacy products. "Aspartame being labeled by IARC [WHO’s International Agency for Research on Cancer] as 'possibly carcinogenic to humans' does not mean that aspartame is actually linked to cancer," says the FDA website.

“The FDA disagrees with IARC’s conclusion that these studies support classifying aspartame as a possible carcinogen to humans. FDA scientists reviewed the scientific information included in IARC’s review in 2021 when it was first made available and identified significant shortcomings in the studies on which IARC relied. We note that JECFA [the Joint FAO/WHO Expert Committee on Food Additives] did not raise safety concerns for aspartame under the current levels of use and did not change the Acceptable Daily Intake (ADI).”

At least, that was the President Joe Biden FDA speaking. A Trump FDA, with Robert F. Kennedy Jr. heading the Dept. of Health and Human Services, already has pressured the food safety agency to get tougher on all chemical additives to food. While color additives are first on RFK Jr.’s hit list, aspartame could be on there somewhere.

Sucralose and saccharin

Sucralose took a hit at the end of March when researchers at the University of Southern California published a study confirming a long-suspected notion regarding many synthetic sweeteners: While they contribute no calories of their own, some synthetic sweeteners increase appetite and therefore intake of calories.

Instead of the brain sending a signal to eat less, “Sucralose activates the area in the brain that regulates hunger, and that activation, in turn, is linked to greater ratings of hunger,” said lead study author Dr. Katie Page. In fact, people who drank water with sucralose said their appetite increased by nearly 20% compared with drinking water with table sugar, Page said.

The key ingredient in Splenda sugar substitutes, sucralose is minimally metabolized by the human body and reaches the colon largely intact -- thereby significantly affecting gut bacteria diversity, another problem area.

Saccharin, the same stuff in Sweet'n Low, is the earliest-known artificial sweetener, dating back to its discovery in 1879. It's often found in soft drinks, fruit juices, baking products and processed foods, and it's roughly 300 times sweeter than traditional sugar.

Early saccharin products contained warning labels listing it as a potential carcinogen after studies in the early 1970s linked it to bladder cancer in rats. More than 30 follow-up studies, however, determined that the results in rats didn't apply to humans. The FDA deemed it safe, and it was removed from the potential carcinogens list in 2000.

Other research suggests saccharin – as well as sucralose – could significantly shift microbiome composition, potentially affecting glucose tolerance and metabolism. Even natural sweeteners like stevia raise similar questions about their microbiota interactions.

Even at moderate consumption levels, saccharin has shown inhibitory effects on beneficial bacteria such as Lactobacillus and Akkermansia muciniphila, contributing to glucose intolerance and inflammation in animal models, according to a study cited in News-Medical.Net. Human studies corroborated these results, suggesting that saccharin can cause gut microbial imbalances linked to metabolic dysfunction.

Other sweeteners

Acesulfame potassium, often shorthanded to ace-K, has a bitter taste so it’s often blended with other sweeteners, especially in beverages. It's a good artificial sweetener to bake with, because it can retain its sweetness even at high temperatures. And it's 200 times sweeter than sugar.

Ace-K seems to have eluded the negative press afforded the other sweeteners above, although one study done on mice found that acesulfame potassium caused weight gain and shifts in the gut microbiome, which could potentially lead to obesity and chronic inflammation.

The sugar alcohols, polyols, such as erythritol and xylitol, are considered some of the safer synthetic sweeteners. Nevertheless, a Cleveland Clinic team conducted a study with healthy volunteers and found “some concerns that a standard serving of an erythritol-sweetened food or beverage may acutely stimulate a direct clot-forming effect,” according to study co-author W. H. Wilson Tang, M.D., research director for Heart Failure and Cardiac Transplantation Medicine at Cleveland Clinic.

The same study saw similar effects from xylitol. “Individuals with higher xylitol levels appeared to have an increased likelihood of experiencing serious cardiac-related events over the following few years.”

The study suggested, “Erythritol and other sugar alcohols commonly used as sugar substitutes should be evaluated for potential long-term health effects, especially when such effects are not seen with glucose itself.”