Aspartame may cause cancer, World Health Organization warns. Here's what to know.
PHILADELPHIA (CBS) -- Aspartame has joined a list of more than 300 other possible cancer-causing agents. The World Health Organization's cancer agency has labeled the artificial sweetener as a possible cause of cancer, but a separate group of experts looking at the same evidence still considers the sugar substitute to be safe.
It's 200 times sweeter than sugar and is the world's most widely used artificial sweetener. Aspartame is found in about 6,000 products worldwide from diet soda to flavored water to yogurt.
The World Health Organization's cancer agency now says aspartame is a "possible carcinogenic," citing "limited evidence" for a "type of liver cancer."
But, according to its own hazard classification, confidence in the assessment was low, admitting more research is needed.
"This shouldn't really be taken as a direct statement that indicates there is a known cancer hazard from consuming aspartame, Schubauer-Berigan, the head of the IARC Monographs program, said.
Another group of experts from the WHO's Food Additive Committee concluded there's "no convincing evidence" aspartame is dangerous if people don't consume more than 40 milligrams per just over 2 pounds of their body weight, meaning the average American would need to drink more than a dozen cans of diet soda a day to be at risk.
"Results do not indicate that occasional consumption poses a risk to most consumers," WHO head of nutrition Francesco Branca said.
Experts say aspartame is a safe and important alternative to sugar.
"Obesity accelerates just about every disease, whether it's cancer, whether it's Type 2 diabetes, hypertension and so on," former U.S. Surgeon General Richard Carmona said, "so there's a reason we wanna reduce sugar consumption."
The U.S. Food and Drug Administration which approved aspartame decades ago is criticizing the WHO finding and reiterated its longstanding position that the sweetener is safe.
The American Cancer Society is calling for more research on aspartame and advising consumers to watch their intake.