Over the past few weeks, aspartame, a commonly used sweetener, has been in the headlines, since information leaked about the International Agency for Research on Cancer (IARC), a research agency of the World Health Organization (WHO), classifying it as “possibly carcinogenic” ahead of the official announcement of the organization.
Aspartame is an artificial sweetener widely used in various food and beverage products since the 1980s, including diet drinks, chewing gum, gelatine, ice cream, dairy products, such as yogurt, breakfast cereal, toothpaste and medications, such as cough drops and chewable vitamins.
The IARC’s classification procedure has been contested in the past for being misleading to consumers. It only establishes the potential of a substance to cause cancer, without providing any additional information on intake levels. Without a complementary assessment from the Food and Agriculture Organization (FAO) Joint Expert Committee on Food Additives (JECFA), which analyses safe intake levels, IARC’s classification is insufficient.
Today, the official hazard and risk assessment from IARC as well as WHO and JECFA have been released. Citing “limited evidence” for carcinogenicity in humans, IARC classified aspartame as possibly carcinogenic to humans (IARC Group 2B) and JECFA reaffirmed the acceptable daily intake of 40 mg/kg body weight.
The assessments of aspartame have indicated that, while safety is not a major concern at the doses which are commonly used, potential effects have been described that need to be investigated by more and better studies.
Dr Francesco Branca, Director of the Department of Nutrition and Food Safety, WHO
The two bodies conducted independent but complementary reviews to assess the potential carcinogenic hazard and other health risks associated with aspartame consumption. After reviewing the available scientific literature, both evaluations noted limitations in the available evidence for cancer (and other health effects).
IARC classified aspartame as possibly carcinogenic to humans (Group 2B) on the basis of limited evidence for cancer in humans (specifically, for hepatocellular carcinoma, which is a type of liver cancer). There was also limited evidence for cancer in experimental animals and limited evidence related to the possible mechanisms for causing cancer.
“We need better studies with longer follow-up and repeated dietary questionnaires in existing cohorts. We need randomized controlled trials, including studies of mechanistic pathways relevant to insulin regulation, metabolic syndrome and diabetes, particularly as related to carcinogenicity”, noted Dr Moez Sanaa, WHO’s Head of the Standards and Scientific Advice on Food and Nutrition Unit.
JECFA concluded that the data evaluated indicated no sufficient reason to change the previously established acceptable daily intake (ADI) of 0–40 mg/kg body weight for aspartame. The committee therefore reaffirmed that it is safe for a person to consume within this limit per day. For example, with a can of diet soft drink containing 200 or 300 mg of aspartame, an adult weighing 70kg would need to consume more than 9–14 cans per day to exceed the acceptable daily intake, assuming no other intake from other food sources.
What does this mean?
We’re not advising companies to withdraw products or consumers to stop consuming altogether, just a bit of moderation.
Dr Francesco Branca, Director of the Department of Nutrition and Food Safety, WHO
The recommendations for aspartame basically stayed the same, nothing has changed and, in the absence of convincing evidence, no increased risk has been determined. “Aspartame, like all low/no calorie sweeteners, when used as part of a balanced diet, provides consumers with choice to reduce sugar intake, a critical public health objective. JECFA has once again reaffirmed aspartame’s safety after conducting a thorough, comprehensive and scientifically rigorous review”, commented Frances Hunt-Wood, Secretary General of the International Sweeteners Association.
“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”, said Kate Loatman, Executive Director of the International Council of Beverage Associations (ICBA).
At the same time however, WHO advises companies to rewrite their recipes to reduce or omit the use of the sweetener. “It’s about changing the formulation of products, and the choice of ingredients so you can have tasty products without the need to use sweeteners”, said Dr Francesco Branca, Director of the Department of Nutrition and Food Safety, WHO.
Moreover, the Financial Times points out that the recent media coverage over the subject is enough to bring aspartame into consumers’ attention, determining them to reduce their consumption of diet sodas. Concerns over the sweetener have previously led to a decline in diet soda consumption in the 2000s and 2010s and even after PepsiCo removed aspartame from its Diet Pepsi in 2015, “the reformulation failed to prevent a further dip in sales and the drinks-and-snacks company reintroduced the sweetener a year later”.
