New Scrutiny For Aspartame, One Of The World’s Most Common Sweeteners

Aspartame, a mainstay of diet beverages for decades, is coming under new scrutiny amid fresh research linking the popular sugar substitute to a possible increased cancer risk.

The U.S. Food and Drug Administration has reviewed the science of aspartame’s safety five times since greenlighting it for consumption in 1981, and more than 90 countries have approved its use. But the World Health Organization recently called two meetings to reevaluate its safety and has signaled that it may issue new warnings about the food additive later this summer.

The American Beverage Association, which represents leading beverage makers such as Coca-Cola and PepsiCo, and other industry organizations are already pushing back. About 95 percent of carbonated soft drinks that have a sweetener use aspartame, as well as about 90 percent of ready-to-drink teas, representing a huge amount of the beverage market share.

“There is a broad consensus in the scientific and regulatory community that aspartame is safe. It’s a conclusion reached time and time again by food safety agencies around the world,” said Kevin Keane, the beverage association’s interim chief executive. “The fact that food safety agencies worldwide, including the FDA, continue to find aspartame safe makes us confident in the safety of our products. And people all over the world should be, too.”

The renewed attention comes at a moment when food and drink aisles are filling with products containing artificial sweeteners, responding to consumer interest in reducing added sugar. This push has sparked new interest in the safety of these sweeteners, including aspartame, one of the world’s most-studied food additives.

Last year, a large observational study in France found that adults who consumed larger amounts of artificial sweeteners, particularly aspartame and acesulfame- K, had a slightly higher cancer risk. The study followed more than 100,000 adults, assessing their self-reported medical history, demographic, diet, lifestyle and health data.

Critics of the study said no causal links could be established, and that observational studies are weaker than randomized clinical trials. The study included women who were on average 42 years old, mostly of healthy weight, fairly physically active and with high levels of education, making it hard to extrapolate to the broader population, critics say.

Earlier, in 2006 and 2007, a team at the Ramazzini Institute in Italy published papers reporting that aspartame caused cancers at multiple sites in rats and mice. The validity of that study, too, has been questioned by critics.

Two World Health Organization working groups are in the process of reviewing the safety of aspartame. The International Agency for Research on Cancer, or IARC, just concluded a meeting in France to assess the potential carcinogenic effect of the sweetener. And the organization’s Joint Organization Expert Committee on Food Additives, known as JECFA, meets June 27 to July 6 to update its risk assessment of aspartame, including reviewing how much can be safely consumed.

The result of both evaluations will be announced on July 14, with many in the nutrition world predicting the WHO will convey new concerns about the sweetener.

Here’s why they think this: In May, the WHO released new recommendations advising against using non-sugar sweeteners to control weight, citing potential health risks including an increased risk of Type 2 diabetes, cardiovascular diseases and early death in adults. They listed common sweeteners such as acesulfame K, aspartame, advantame, cyclamates, neotame, saccharin, sucralose, stevia and stevia derivatives as ones to avoid.

The WHO said the recommendation was conditional and would be followed by the organization developing guidelines.

An FDA spokesperson said in a statement to The Washington Post this week that while it would be inappropriate for the FDA to speculate on potential scenarios surrounding other organizations’ assessments of aspartame, “the FDA can confirm that scientific evidence has continued to support its conclusion that aspartame is safe for the general population.”

The U.S. Department of Health and Human Services recently wrote a letter to the WHO criticizing the agency for conducting two subcommittee reviews simultaneously and asking that only one subcommittee guide its thinking – a sign, food safety advocates say, that U.S. regulators are worried about the upcoming recommendation.

The WHO declined the U.S. health agency’s request, responding in a letter that, “given the availability of new research results,” aspartame was a “high priority” for evaluation by both subcommittees.

The FDA posted both letters on its website and in May and bolstered its “aspartame and other sweeteners” webpage – moves that indicate the agency “may be starting to dig in” and reinforce its position that aspartame is safe, said Peter Lurie, director of Center for Science in the Public Interest.

“They seem to be worrying in advance of the most authoritative review of the safety of this product,” Lurie said. “But even if FDA chose to ignore what WHO has to say, the IARC pronouncement would still have a lot of pull in the rest of the world.”

Robert Rankin, president of the Calorie Control Council, the trade group for manufacturers of artificial sweeteners, downplayed the potential impact of a warning from the WHO’s cancer subcommittee.

“IARC focuses on finding substances that could cause cancer and have concluded working at night, using aloe vera, and drinking hot water are carcinogenic, and classify processed meats the same as tobacco and asbestos,” he said. “Real world context on risk is essential and IARC does not provide that.”

(c) 2023, The Washington Post · Laura Reiley