Aspartame

Aspartame, a low-calorie artificial sweetener, has been permitted for use as a food additive in Canada since 1981 in a number of foods including soft drinks, desserts, breakfast cereals and chewing gum and is also available as a table-top sweetener. It is made by the bonding together of the amino acids aspartic acid and phenylalanine, which are normal constituents of proteins, to form a dipeptide which is further esterified with methanol.

In Canada, food additives such as aspartame are subjected to rigorous controls under the Food and Drugs Act and Regulations. Before any food additive is permitted for use, manufacturers are required to file a food additive submission in accordance with Section B.16.002 of the Regulations. A submission must contain detailed information, including the results of safety tests, as well as information respecting the utility of the additive in question.

Before consideration was given to permitting aspartame for use in foods in Canada, officials of Health Canada evaluated an extensive array of toxicological tests in laboratory animals and, since its listing for use, they have examined the results of a number of clinical studies in humans. There is no evidence to suggest that the consumption of foods containing this sweetener, according to the provisions of the Food and Drug Regulations and as part of a well-balanced diet, would pose a health risk to consumers. In addition, other scientific advisory bodies such as the Scientific Committee for Food of the European Community, and the Joint Expert Committee on Food Additives (JECFA) of the United Nations Food and Agriculture Organization and World Health Organization have reviewed all the available safety studies and have found aspartame to be safe. More than ninety countries world-wide, including the United States ^{Footnote 1}, countries of the European Union ^{Footnote 2}, and Australia and New Zealand ^{Footnote 3}, have also reviewed aspartame and found it to be safe for human consumption and allow its use in various foods.

Although aspartame can be safely consumed by most healthy individuals, it has long been recognized that excessive intake of phenylalanine, one of the constituent amino acids of aspartame, can pose a hazard to individuals suffering from an inherited metabolic disorder called phenylketonuria. For this reason, all foods sweetened with aspartame have a statement in bold font at the end of the list of ingredients that aspartame contains phenylalanine.

An acceptable daily intake (ADI) of 40 milligrams/kilogram of body weight per day (40 mg/kg bw per day) was established by Health Canada before aspartame was permitted for use as a food additive in Canada. An ADI is an estimate of the amount of a substance in food that can be consumed daily over a lifetime without presenting an appreciable risk to health. The same ADI of 40 mg/kg bw per day had also been established for aspartame by the Joint FAO/WHO Expert Committee on Food Additives (JECFA).

Health Canada has reviewed the summary reports of the assessments on aspartame by JECFA and the WHO’s International Agency for Research on Cancer (IARC) that were published on July 13, 2023. The WHO referred to the two evaluations as complementary and indicated that their sequence and the close collaboration of the two secretariats allowed for a comprehensive evaluation of the health effects of consuming aspartame based on the latest available evidence^{Footnote 4}. JECFA reaffirmed the ADI of 40 mg/kg bw per day and did not raise safety concerns for aspartame under the current levels of use. As a result, Health Canada will not take further action on aspartame at this time.

If new scientific information becomes available, the department will determine whether action on aspartame is needed to protect people in Canada. Action Health Canada could take, if necessary, includes reducing one or more maximum levels of use for aspartame, further restricting which foods it may be used in, or no longer permitting it to be used as a food additive.

Health Canada has additional information about sugar substitutes and healthy eating.