Aspartame

Aspartame is a methyl ester of a dipeptide used as a synthetic nonnutritive sweetener in over 90 countries worldwide in over 6000 products.

Aspartame has been the subject of much controversy in recent times.

Animal studies have failed to show a carcinogenic activity in aspartame. Only two recent studies on rats treated with variable doses of aspartame and followed until natural death found an excess of malignant neoplams, mainly lymphomas and leukemias in females, but not in males. Such an apparent excess can, however, be explained by the longer life of animals treated with aspartame, as well as by the higher rates of infections in the study animals (1).

Current use levels of aspartame, even by high users in special subgroups, remains well below the U.S. Food and Drug Administration and European Food Safety Authority established acceptable daily intake levels of 50 and 40 mg/kg body weight/day, respectively. Consumption of large doses of aspartame in a single bolus dose will have an effect on some biochemical parameters, including plasma amino acid levels and brain neurotransmitter levels. The rise in plasma levels of phenylalanine and aspartic acid following administration of aspartame at doses less than or equal to 50 mg/kg body weight do not exceed those observed postprandially (2).

Recently, a team of nine independent internationally esteemed toxicologists led by Bernadene Magnuson, reviewed hundreds of studies on aspartame safety (3).

The key findings of the review with respect to aspartame safety were:

- Aspartame is completely broken down in the intestine to components found in other foods.

- Aspartame consumption (even at levels much higher than consumed by the highest users) has virtually no impact on blood levels of amino acids, methanol or glucose.

- Aspartame safety is clearly documented and well established through extensive laboratory testing, animal experiments, human clinical trials and epidemiological (population) studies.

There is no evidence from numerous well conducted studies that consumption of aspartame at levels found in the human diet are associated with conditions of nervous system, behaviour, or other illness.

Aspartame does not cause mutations, and there is no credible evidence that it causes cancer.

Journal Reference

Bosetti C, Gallus S, Talamini R, Montella M, Franceschi S, Negri E, La Vecchia C. Artificial sweeteners and the risk of gastric, pancreatic, and endometrial cancers in Italy. Cancer Epidemiology, Biomarkers & Prevention 2009;18(8):2235-8.

Magnuson BA, Burdock GA, Doull J, Kroes RM, Marsh GM, Pariza MW, Spencer PS, Waddell WJ, Walker R, Williams GM. Aspartame: a safety evaluation based on current use levels, regulations, and toxicological and epidemiological studies. Critical Reviews in Toxicology. 2007;37(8):629-727.

Magnuson BA. Aspartame--facts and fiction. Journal of the New Zealand Medical Association. 2010 Mar 19;123(1311):53-7.

Bernadene Magnuson, PhD, is an Adjunct Professor in Nutritional Sciences at the University of Toronto, and Senior Scientific & Regulatory Consultant for Cantox Health Sciences International, a leading international consulting firm providing regulatory and toxicology expertise. Recently, her work is focused on safety assessments of various dietary ingredients and supplements.

Dr Magnuson has published numerous peer-reviewed articles, book chapters, abstracts and professional articles, is on the editorial board of two journals and is an active member of various committees of the Institute of Food Technologists and the Society of Toxicology. Picture Credit 1. Picture Credit 2.