Should My Clients Consume Less Aspartame? The Recent WHO/IARC Report on the Health Impacts of Aspartame

What’s happening?

The Joint Expert Committee on Food Additives, made up of the World Health Organization (WHO) and the International Agency for Research on Cancer (IARC), just released a report assessing the health impacts of aspartame (1). The PEN Team has been watching the media headlines in anticipation of the report’s release to determine whether a change in practice recommendation was needed on the safety of the daily consumption of aspartame.

Analysis

IARC has classified aspartame as possibly carcinogenic to humans based on limited evidence (Group 2B) (1). This assessment should be understood within IARC’s hazard analysis of other substance-related carcinogens.

Examples of Substance-related Carcinogenic Hazards to Humans (1-3)

Group Classification	Substance-related Agent	Hazard Analysis
1	Alcoholic beverages Processed meats (e.g. salami, hot dogs, bacon)	Carcinogenic to humans
2A	Red meat (e.g. beef, pork, lamb, goat) High temperature frying	Probably carcinogenic in humans
2B	Aspartame Pickled vegetables	Possibly carcinogenic in humans

Aspartame is an approved nonnutritive sweetener in Australia, Canada and the European Union (4). Based on the recent assessment, the Joint Expert Committee states there is “no sufficient reason to change the previously established Acceptable Daily Intake (40 mg/kg of body weight)” (1). This would equal the amount of aspartame contained in nine to 14 cans of diet soft drinks per day.

Now what?

Dietitians are expected to respond to media assertions of the safety of aspartame in the context of everyday eating patterns. Dietitians can help address client concerns by relaying the following information:

While aspartame is classified as possibly carcinogenic to humans, the hazard assessment is based on limited evidence for cancer in humans.
Food products that have aspartame as an ingredient must be labelled to alert customers to the presence of phenylalanine (for individuals with phenylketonuria (PKU)) (including the European Food Safety Authority, Food Standards Australia New Zealand and Health Canada) (2).
Sweeteners undergo country-specific safety assessments and evaluation processes before approval for use.
The Acceptable Daily Intake for aspartame is 40 mg/kg of body weight/day (1). It is recognized internationally and is the same as what was established and recently reaffirmed by the Joint Expert Committee of Food Additives (5), except for individuals with PKU (2). At this time, the U.S. Food and Drug Administration suggested a limit for aspartame of 50 mg/kg of body weight and disagrees with the assessment of carcinogenic risk (6).
Substituting free/added sugars with sweeteners, such as aspartame, is an approach to reduce both sugar and caloric intake for diabetes management/glycemic control (7). Clients should be mindful of their cumulative aspartame consumption across products including diet drinks, chewing gum, dairy products such as yogurt, and medications including chewable vitamins (1).
If a client prefers to no longer use aspartame, dietitians can offer suggestions on alternative sweeteners, other beverages (e.g. water), and foods that provide natural sweetness (e.g. dates, agave nectar).
In addition to avoiding or limiting foods that may cause cancer, clients should be reminded of foods that are protective against cancer, including whole grains, nuts, seeds, vegetables, fruit and healthy fats (8).

The PEN Team will continue to monitor the evidence as more research is published related to the safety of aspartame. The PEN System has evidence-informed nutrition recommendations to support your practice:

Sweeteners Knowledge Pathway:
Recent Trending Topics related to the safety of nonnutritive sweeteners:
- New Non-Sugar Sweetener Guideline from the World Health Organization
- Does Erythritol Consumption Add to Cardiovascular Risk?

References

World Health Organization (WHO). Aspartame hazard and risk assessment results released. 2023 Jul. Available from: https://www.who.int/news/item/14-07-2023-aspartame-hazard-and-risk-assessment-results-released
International Agency for Research on Cancer (IARC). Monographs on the identification of carcinogenic hazards to humans. 2023 Jul. Available from: https://monographs.iarc.who.int/list-of-classifications/
World Cancer Research Fund (WCRF)/American Institute for Cancer Research (AICR). Continuous Update Project Expert Report 2018. Wholegrains, vegetables and fruits and the risk of cancer. 2018. Available from: https://www.wcrf.org/dietandcancer/exposures/wholegrains-veg-fruit
Dietitians of Canada. What is the evidence on the safety of sweeteners (e.g. nonnutritive, artificial, intense, low calorie, sugar substitutes)? In: Practice-based Evidence in Nutrition^® [PEN]. 2021 Mar. Available from: https://www.pennutrition.com/KnowledgePathway.aspx?kpid=1323&pqcatid=146&pqid=1295. Access only by subscription. Click Sign Up on PEN login page.
Health Canada. Aspartame. 2023 July. Available from: https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-additives/sugar-substitutes/aspartame-artificial-sweeteners.html
Food and Drug Administration. Aspartame and Other Sweeteners in Food. 2023 July. Available from: https://www.fda.gov/food/food-additives-petitions/aspartame-and-other-sweeteners-food
Dietitians of Canada. Sweeteners Background. In: Practice-based Evidence in Nutrition^® [PEN]. 2021 Mar. Available from: https://www.pennutrition.com/KnowledgePathway.aspx?kpid=1323&trid=17857&trcatid=38. Access only by subscription. Click Sign Up on PEN login page.
Dietitians of Canada. What nutrients/dietary factors are associated with a decreased risk of developing cancer? In: Practice-based Evidence in Nutrition^® [PEN]. 2022 Mar. Available from: https://www.pennutrition.com/KnowledgePathway.aspx?kpid=8996&pqcatid=145&pqid=8967. Access only by subscription. Click Sign Up on PEN login page.