FDA says aspartame is safe, disagrees with WHO on possible cancer link

The FDA disagrees with the World Health Organization’s finding that the widely used soda sweetener aspartame probably causes cancer in humans, saying that the studies used to reach that conclusion have “significant shortcomings.”

“Aspartame is one of the most studied food additives in the human food supply,” a spokesperson for the agency said late Thursday, shortly after the WHO announced its findings. “FDA scientists have no safety concerns when using aspartame.” under the approved conditions.

The International Agency for Research on Cancer, a body of the World Health Organization, has found a possible link between aspartame and a type of liver cancer called hepatocellular carcinoma after reviewing three large human studies in the United States and Europe.

Aspartame is used as a sugar substitute in about 6,000 products around the world, according to the Calorie Control Councila trading group representing manufacturers of artificial sweeteners.

Historically, artificially sweetened beverages are the largest source of exposure to aspartame. A sugar substitute is used in diet soft drinks such as Diet Coke and Pepsi Zero Sugar.

Aspartame is widely used because it is 200 times sweeter than sugar, which means that drinks with a substitute taste similar to products containing sugar, but contain fewer calories.

Dr. Marie Shobur-Berigan, a senior official at IARC, confirmed that the World Health Organization’s classification of aspartame as a probable carcinogen is based on limited evidence.

Schubauer-Berigan acknowledged during a news conference with reporters Wednesday that the studies could contain flaws that skew the results. She said the designation should be seen as a call for more research into whether aspartame can cause cancer in humans.

“This should not be taken as a direct statement that there is a known cancer risk from ingesting aspartame,” Schopur-Brigan said.

An FDA spokesperson said that the classification of aspartame as “probably a human carcinogen” does not mean that the sugar substitute is actually linked to cancer. The spokesperson said Health Canada and the European Food Safety Authority have also concluded that aspartame is safe at current tolerable levels.

A separate panel of international scientists called the Joint Expert Committee on Food Additives said on Thursday that evidence of an association between aspartame and cancer in humans is not convincing. JECFA is an international group made up of scientists from the World Health Organization and the Food and Agriculture Organization of the United Nations.

The Joint Expert Committee (JECFA) makes recommendations about the amount of product that people can safely consume. The organization maintains its recommendation that it is safe for a person to consume 40 milligrams of aspartame per kilogram of body weight per day during their lifetime.

An adult who weighs 70 kilograms, or 154 pounds, would have to drink more than nine to 14 cans of aspartame-containing soda a day to exceed the limit and possibly face health risks.

The US Department of Health and Human Services told the WHO in an August 2022 letter that the Joint Expert Committee (JECFA) is best suited to make public health recommendations about the safety of aspartame in food.

This is because the JECFA reviews all available data, both public and private domain information, while IARC only considers public data.

“Thus, by comparison, the IARC review of aspartame would be incomplete and its conclusion may be confusing to consumers,” Mara Burr, who heads HHS’s office of multilateral relations, wrote in the letter.

The US Food and Drug Administration (FDA) has a slightly higher recommendation than the JECFA and says it is safe for a person to consume 50 milligrams of aspartame per kilogram of body weight per day during their lifetime. A person weighing 132 lbs should consume 75 cans of aspartame per day to get this far.