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 and potential benefits to the consumer 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 hazard 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 StatesFootnote 1, countries of the European UnionFootnote 2, and Australia and New ZealandFootnote 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 containing aspartame must indicate on the label the presence of phenylalanine.
An acceptable daily intake (ADI) of 40 milligrams/kilogram of body weight/day was established by scientists in the Food Directorate of Health Canada. This ADI is recognized internationally and is the same as that established by the Joint Expert Committee on Food Additives (JECFA) of the Food and Agriculture Organization/World Health Organization (FAO/WHO).
As part of a post-market surveillance program, a study was conducted in 1987 to monitor the actual consumption of aspartame in Canada. This study which involved 5200 Canadian households and 7500 individuals, demonstrated that the actual consumption of aspartame was well below the recommended ADI even during the warmest period of the year when soft drink consumption would be expected to be high. Furthermore, follow-up studies on human subjects revealed that no adverse effects were observed even when humans were exposed to higher intakes than the established ADI.
Intakes of aspartame would be expected to be even lower now since other high-intensity sweeteners such as acesulfame-K and sucralose have been approved for use and compete on the market with aspartame.
Inspite of decades of scientific research attesting to the safety of aspartame, negative allegations about the safety of aspartame have appeared in the media and on the internet for a number of years. Some of the most common allegations and the scientific facts refuting them are as follows.
While methanol is a by-product of aspartame digestion, it is not foreign to the human diet. The pectin in many common foods including fruits and vegetables and their juices contains low levels of methanol and substances that are metabolised to methanol. A cup of tomato juice would provide about six times more methanol than a cup of aspartame-containing soft drink. Dietary methanol, whether it comes from aspartame or common foods, is present at levels too low to cause any health problems. It does not accumulate in the body but is metabolised through normal metabolic pathways to formaldehyde, then to formic acid and finally to water and carbon dioxide.
As the Multiple Sclerosis Society of Canada has stated in a Medical Update Memo, there has been no published peer-reviewed research supporting a link between aspartame and multiple sclerosis and no evidence of an MS "epidemic" exists.
When the evaluation of the safety of aspartame was conducted by Health Canada, possible susceptible populations, including persons with diabetes, were taken into consideration. Studies before and after approval of aspartame have shown that it can be used safely by people with diabetes.
A review of the available studies on aspartame and glycemic control is available in a recent publication (The Clinical Evaluation of a Food Additive: Assessment of Aspartame. 1996. Edited by C. Tschanz et al. CRC Press). The conclusion of the authors was that in five well-conducted studies, the addition of aspartame to the diabetic diet in single doses or for prolonged periods of time did not affect control of blood sugar levels. In addition, there were no effects on parameters indicative of insulin counter-regulation.
Scientists in the world-wide scientific community, including Canadian scientists, have found no link between aspartame consumption and the incidence of cancer or brain tumours from a study of the safety studies performed with aspartame.
Clinical studies conducted by medical researchers have shown that there is no link between aspartame consumption and seizures.
One study was conducted on children and adults claiming to have experienced aspartame-induced seizures. On some days they were given a placebo and on other days they were given a large single dose of aspartame. Monitoring by EEG of their brain signals demonstrated that aspartame was no more likely to cause seizures than a placebo.
Another study on children with a medical history of seizures showed that aspartame did not induce or worsen seizures in these seizure-prone subjects.
Investigation of reports from people claiming to have had allergic reactions to aspartame did not demonstrate a link between aspartame and allergic reactions.
Voir 21 CFR 172.804, U.S. Code of Federal Regulations.
Voir la Directive 94/35/CE du Parlement européen et du Conseil du 30 juin 1994 concernant les édulcorants destinés à être employés dans les denrées alimentaires.
Voir Standard A8, Australia-New Zealand Food Authority.