The FDA says aspartame is protected and disagrees with the WHO on a attainable hyperlink to most cancers

Cans of PepsiCo’s Pepsi Zero Sugar soda are displayed for a staged photograph taken on Wednesday, April 17, 2019, in Tiskilwa, Illinois.

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The U.S. Food and Drug Administration disagrees with the World Health Organization’s finding that the widely used soda sweetener aspartame may cause cancer in humans, saying the studies used to reach that conclusion had “significant flaws.”

“Aspartame is one of the best-studied food additives in the human diet. FDA scientists have no safety concerns when aspartame is used under approved conditions,” a spokesman for the agency said late Thursday, shortly after the WHO released its findings.

The International Agency for Research on Cancer, a WHO panel, has found a possible link between aspartame and a type of liver cancer called hepatocellular carcinoma after reviewing three large human studies in the US and Europe.

According to the Calorie Control Council, a trade group representing manufacturers of artificial sweeteners, aspartame is used as a sugar substitute in about 6,000 products worldwide.

Artificially sweetened beverages have historically been the largest source of aspartame exposure. The sugar substitute is used in diet sodas like Diet Coke and Pepsi Zero Sugar.

Aspartame is commonly used because it’s 200 times sweeter than sugar, meaning drinks containing the substitute taste similar to products with sugar but have fewer calories.

dr Mary Schubauer-Berigan, a senior IARC official, stressed that the WHO’s classification of aspartame as a possible carcinogen was based on limited evidence.

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Schubauer-Berigan admitted during a press conference with journalists on Wednesday that the studies could contain errors that skew the results. She said the classification should be seen as a call for more research into whether aspartame can cause cancer in humans.

“This shouldn’t really be taken as a direct statement that there is a known risk of cancer from aspartame use,” Schubauer-Berigan said.

The FDA spokesman said the classification of aspartame as “possibly carcinogenic to humans” does not mean that the sugar substitute is actually linked to cancer. Health Canada and the European Food Safety Authority have also concluded that aspartame is safe at current allowable levels, the spokesman said.

A separate panel of international scientists called the Joint Expert Committee on Food Additives said Thursday that the evidence linking aspartame to human cancer was not convincing. JECFA is an international group made up of scientists from WHO and the UN Food and Agriculture Organization.

JECFA provides recommendations on how much of a product people are safe to consume. The organization maintained its recommendation that it is safe for a person to consume 40 milligrams of aspartame per kilogram of body weight daily over the course of their lives.

An adult weighing 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 face potential health risks.

The US Department of Health and Human Services told WHO in an August 2022 letter that JECFA was better placed to make public health recommendations on the safety of aspartame in food.

This is because JECFA examines all available data, both public and private proprietary information, while IARC only looks at public data.

“As such, an IARC review of aspartame would be incomplete and its conclusion could be confusing for consumers,” Mara Burr, director of HHS’s office of multilateral relations, wrote in the letter.

The FDA has a slightly higher recommendation than the JECFA, saying it’s safe for a person to consume 50 milligrams of aspartame per kilogram of body weight daily over their lifetime. To reach this limit, a person weighing 60 kilograms would need to consume 75 packets of aspartame per day.