Cans of PepsiCo’s Pepsi Zero Sugar soda are on display for an arranged photo taken in Tiskilwa, Illinois, on Wednesday, April 17, 2019.
Daniel Akker | Bloomberg | Getty Images
The U.S. Food and Drug Administration disagrees with a World Health Organization finding that the widely used soft drink sweetener aspartame may cause cancer in humans, saying the studies used to reach that conclusion showed “significant flaws.”
“Aspartame is one of the most studied food additives in the human food supply. FDA scientists are not concerned about safety when aspartame is used under its approved terms,” an agency spokesman said late Thursday, shortly after the WHO released its findings.
The International Agency for Research on Cancer, an organization of the WHO, found a possible link between aspartame and a form of liver cancer called hepatocellular carcinoma after reviewing three large human studies in the US and Europe.
Aspartame is used as a substitute for sugar in about 6,000 products worldwide, according to the Calorie Control Councila trade group representing manufacturers of artificial sweeteners.
Artificially sweetened beverages have historically been the largest source of aspartame exposure. The 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, meaning drinks containing the substitute are similar to products with sugar, but have fewer calories.
Dr. Mary Schubauer-Berigan, a senior official at IARC, stressed that the WHO’s classification of aspartame as a possible carcinogen is based on limited evidence.
Schubauer-Berigan acknowledged during a press conference with journalists on Wednesday that the studies may contain errors that distort the results. She said the classification should be seen as a call for more research into whether aspartame can cause cancer in humans.
“This should not really be taken as a direct statement indicating that there is a known risk of cancer from consuming aspartame,” Schubauer-Berigan said.
The FDA spokesperson said that aspartame’s classification 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 permitted levels, the spokesperson said.
A separate body of international scientists called the Joint Expert Committee on Food Additives said Thursday that the evidence of an association between aspartame and cancer in humans is inconclusive. JECFA is an international group made up of scientists from the WHO and the Food and Agriculture Organization of the UN.
JECFA makes recommendations about how much of a product people can safely 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 during their lifetime.
An adult weighing 70 pounds would have to drink more than nine to 14 cans of aspartame-containing soda daily to exceed the limit and may be at risk for health.
The U.S. Health and Human Services Department told WHO in an August 2022 letter that JECFA is better suited to provide public health recommendations on the safety of aspartame in food.
This is because JECFA reviews all available data, both public and private property information, while the IARC only looks at public data.
“Thus, an IARC review of aspartame would be incomplete by comparison, and its conclusion could be confusing to consumers,” Mara Burr, chief of the HHS office of multilateral relations, wrote in the letter.
The FDA has a slightly higher recommendation than JECFA, saying it is safe for a person to consume 50 milligrams of aspartame per kilogram of body weight daily during their lifetime. A person who weighs 132 pounds should consume 75 packets of aspartame per day to reach this limit.