Aspartame may cause cancer but you would have to consume excessive amounts — WHO

The World Health Organisation (WHO) has classified popular artificial sweetener aspartame as a possible carcinogen, meaning it could cause cancer, but the world body says it is safe if consumed within limits. 

After independent but complementary reviews by the International Agency for Research on Cancer (IARC) and an international scientific expert committee, WHO and the Food and Agriculture Organisation joint expert committee on food additives (JECFA), the two bodies identified a possible link between aspartame and a type of liver cancer called hepatocellular carcinoma, but that science is not conclusive.  

In a joint statement on Friday, WHO said aspartame is safe if 40mg per kilogram of a person’s bodyweight is consumed. An adult weighing 70kg would have to drink more than nine to 14 cans of aspartame-containing soft drink daily to exceed the limit and potentially face health risks. 

The IARC classified aspartame as possibly carcinogenic to humans (group 2B) on the basis of limited evidence for cancer in humans.

“There was also limited evidence for cancer in experimental animals and limited evidence related to the possible mechanisms for causing cancer.”

Some of the products that contain aspartame include diet soft drinks, chewing gum, dairy products such as yoghurts and ice cream, toothpaste and certain medications such as cough mixtures.

This is the first time the IARC has evaluated aspartame and the third time for the expert committee JECFA. 

“Cancer is one of the leading causes of death globally. Every year, one in six people die from cancer. Science is continuously expanding to assess the possible initiating or facilitating factors of cancer in the hope of reducing these numbers and the human toll,” said Dr Francesco Branca, WHO director of the department of nutrition and food safety.

“The assessments of aspartame have indicated that while safety is not a major concern at the doses commonly used, potential effects have been described that need to be investigated by more and better studies.” 

JECFA concluded the data evaluated indicated no sufficient reason to change the previously established daily intake of 0-40mg per kg and the committee “reaffirmed it is safe for a person to consume within this limit per day”.  

The WHO called for more research to refine the understanding of a possible carcinogenic hazard. Dr Moez Sanaa, WHO head of the standards and scientific advice on food and nutrition unit, said: “We need better studies with longer follow-up and repeated dietary questionnaires in existing cohorts. We need randomised controlled trials, including studies of mechanistic pathways relevant to insulin regulation, metabolic syndrome and diabetes, particularly as related to carcinogenicity.” 

The International Council of Beverages Associations (ICBA), a world body that represents the interests of the non-alcoholic beverage industry, said the latest findings about aspartame confirm it can be safely consumed daily over a lifetime. 

ICBA executive director Kate Loatman said: “This definitive conclusion by the world's leading health and food safety experts again affirms aspartame is safe. After rigorous review, this landmark WHO and FAO finding further strengthens confidence in the safety of aspartame and will play a vital role in informing consumers as they consider all options to reduce sugar and calories in their diets.”

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