On Thursday, the International Research Agency on Cancer, an arm of the World Health Organization (WHO), issued a statement identifying aspartame β a sugar substitute prevalent in diet sodas and other sugarless foods β as a potential carcinogen.
Contrarily, the WHO’s Expert Committee on Food Additives maintained its established safety benchmark for daily aspartame intake at 40 milligrams for adults weighing roughly 154 pounds β equivalent to approximately 14 cans of Diet Coke. Similarly, the U.S. Food and Drug Administration (FDA) also upholds a marginally higher limit of 50 milligrams per day for an adult weighing around 132 pounds.
Barry Popkin, a nutrition professor at the University of North Carolina Gillings School of Global Public Health, explained that the WHO’s announcement doesn’t entirely discourage aspartame consumption. “It’s more of a gentle nudge towards caution, rather than an outright ban,” he stated. “Moderate consumption shouldn’t cause undue concern.”
Used in an extensive range of over 5,000 food and beverage products, aspartame is significantly sweeter than sugar. The FDA gave the green light for its usage as a sweetener and food ingredient in items such as gum, cereals, instant coffee, and dairy products in 1974. Products that frequently contain aspartame comprise:
- Sweetening packets such as Sugar Twin.
- Beverages and drink concentrates like Diet Coke, Snapple, Fanta Zero, Sprite Zero, Crystal Light.
- Sugarless gum varieties, including Trident, Extra, Wrigleyβs.
- Gelatin-based products such as sugar-free Jell-O.
- Sugar-Free Syrup including Log Cabin Sugar-Free Syrup.
Aspartame, Cancer Risk, and Scientific Findings
The WHO categorizes aspartame below two other risk levels: “carcinogenic to humans” and “probably carcinogenic.” This “potential carcinogen” category also encompasses substances like aloe vera, pickled vegetables, and nickel.
Historical research on aspartame’s association with cancer hasn’t definitively proven its causal role in the disease. Many investigations seeking connections between cancer and artificial sweeteners have primarily relied on animal-based studies, according to Popkin.
A study conducted in 2020 discovered an elevated incidence of leukemia and lymphoma in mice that ingested aspartame. However, the administered doses were almost four times the mice’s body weight, which Popkin argues limits their relevance to human risk. In contrast, studies from the 1980s concluded that aspartame did not induce brain tumors or bladder cancer in rats.
A more recent study from 2022 involving over 100,000 adults in France indicated a slightly heightened risk of cancer from consuming substantial amounts of artificial sweeteners.
Potential Health Risks of Artificial Sweeteners
Despite the WHO’s statement suggesting aspartame might be more harmful than other artificial sweeteners, Popkin argues that all could potentially lead to negative health outcomes.
“In all honesty, the difference is so marginal that it should be prudent to treat all diet sweeteners in the same manner,” Popkin opined. “However, consuming excessive amounts, such as 10 cans of Diet Coke or Diet Pepsi in a day, should be avoided. Such overindulgence edges towards the threshold of potential carcinogenic levels.”
Past studies have associated artificial sweeteners with an increased likelihood of heart disease, hypertension, diabetes, and obesity.
In May, the WHO recommended against using artificial sweeteners as a weight-loss tactic, citing lack of evidence that they contribute to long-term body fat reduction.
“For those consuming large quantities of soda daily, substituting with low-calorie artificial sweeteners might be a healthier alternative than consuming the equivalent amount of added sugar,” advised Dariush Mozaffarian, a nutrition professor at Tufts University. “However, these aren’t a guaranteed safe haven. As much as possible, their use should be limited.”
The aforementioned French study in 2022 revealed an increased risk of stroke in individuals consuming aspartame. It also concluded that substituting added sugar with artificial sweeteners did not diminish heart disease risk.
Moreover, a study published last year by Israeli scientists found that artificial sweeteners could disrupt the composition of gut microbes.
Mozaffarian recommends a balanced, natural diet featuring naturally sweet foods. “Think of artificial sweeteners as a transitional aid away from high amounts of added sugar, but not necessarily a safe alternative,” he added.