I’m a dentist. I’m begging people not to give up on aspartame

The International Agency for Research on Cancer (IARC, an entity within the World Health Organization) recently announced that aspartame, a sugar substitute used in about 6,000 products worldwide, is “possibly carcinogenic to humans.”

If this sounds familiar, it’s because reports of this assessment have circulated for two weeks, after anonymous sources leaked it to the press. The leak triggered a heated debate among experts on the benefits and alleged risks of the widespread use of sugar substitutes, also known as non-nutritive sweeteners. This includes saccharin, sucralose, stevia, monk fruit and others, though IARC only evaluated aspartame.

I am a dentist and a mother of three. I know that even the most responsible parents will not be able to stop children from eating sweets altogether, but we can point them to healthier choices. My professional concern for oral health makes opting for non-nutritive sweeteners over sugar obvious. The aspartame reports have not changed my mind as the link to cancer looks tenuous at best, even by the World Health Organization’s own risk assessment standard. Press reports in the U.S. and across the Atlantic confirm this.

For the U.S. Food and Drug Administration, there is no debate about aspartame, one of the most common sugar substitutes in food items like dentist-preferred diet soda and some sugar-free gum. The agency released a statement vehemently disagreeing with IARC’s classification and emphasizing that reviews conducted by its own scientists found no safety concerns.

“Aspartame being labeled by IARC as ‘possibly carcinogenic to humans’ does not mean that aspartame is actually linked to cancer,” the agency said. “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.”

One reason for such a strong response is the FDA’s well-founded concerns that most people will interpret IARC’s announcement as saying that aspartame causes cancer. The FDA even acknowledged that navigating different information from health organizations is challenging for consumers.

It becomes even more difficult in light of the fact that IARC’s aspartame assessment does not consider risk or the likelihood of harm — merely hazard, which is only the potential for harm.

Everything in the physical world is a hazard, depending on the dose. Take the sun: While some sunlight is necessary for good health and vitamin D, too much will cause a sunburn or even damage the DNA in our cells and cause cancer. Likewise, water is essential for life, but potentially fatal water poisoning called hyponatremia can occur if a person drinks too much.

That’s how consumers can make sense of the fact that at the same time as that of IARC’s announcement, another WHO committee affirmed that the approved daily intake levels for aspartame weren’t changing as a result of the new carcinogenic categorization.

It seems clear from FDA’s response that the agency considers IARC’s conclusion neither accurate nor helpful. IARC’s credibility frequently has been challenged in the past for their classification system being confusing to the general public and even scientists, as well as for how they have conducted individual monographs.

In 2018, the U.S. House Committee on Appropriations even withheld funding (later restored) for IARC over concerns about irregularities and conflicts of interest in the agency’s glyphosate monograph.

For consumers, alphabet-soup agencies mean less than the practical question: If non-nutritive sweeteners were to fall out of use altogether, would our health be in a better or worse position?

The answer is obvious: We’d be in a worse place because of our relationship with sugar, which humans crave.

Dentists hold sugar in a kind of awe-struck horror. Sugar consumption feeds mouth bacteria, which produce as a by-product a form of acid that erodes tooth enamel. If left unchecked, this leads to dental cavities and oral disease. This is true even of healthier, more natural forms of sugar, such as the fructose found in fruit.

Non-nutritive sweeteners satiate our cravings for sweetness, while reducing the urge to consume large quantities of high-calorie, tooth decaying sugar. In the case of sugar-free gum, long recognized by dentists as a valuable oral health tool, these benefits are even more pronounced. As I have written, I even encourage my kids to chew sugar-free gum after eating Halloween candy, because it both promotes oral health and can help keep them from wanting to binge.

By stimulating the production of saliva through chewing, gum helps us to readjust the chemical balance of the mouth by producing minerals like calcium and phosphates. This “remineralization” process reverses damage caused by cavity-making acids, and reduces levels of plaque.

Research bears this out. One 2019 study by King’s College London found that people who regularly chew sugar-free gum develop about 28% fewer cavities than those who don’t — more so than for fluoride toothpaste.

More is at stake than just cavities. Oral health affects the rest of the body. Gum disease and related conditions have been linked to a variety of broader health problems. Pneumonia can be caused by certain mouth bacteria getting pulled into the lungs. Endocarditis, an infection of the lining of the heart, can result from mouth bacteria traveling through the bloodstream. Some research links heart disease, clogged arteries, and stroke to inflammation from oral bacteria. Helping reduce harmful mouth bacteria, prevent gum disease, and protect tooth enamel is precisely what chewing sugar-free gum can do.

Consequently, maintaining access to an inexpensive oral health support like sugar-free gum could have an outsized effect on overall health. It’s clear that while aspartame’s link to cancer is unproven, the significant benefits of maintaining good oral health are worth chewing over.

Melissa Weintraub is a mother and dentist who blogs at The Mommyhood Chronicles. She is a member of the American Dental Association.