Safety of aspartame

Abstract

In his letter (Feb 1, p 362),1Roberts HJ Aspartame and brain cancer.Lancet. 1997; 349: 362Summary Full Text Full Text PDF PubMed Scopus (4) Google Scholar Roberts questions the safety of aspartame. However, there is no evidence of an association between aspartame and brain tumours from animal studies or epidemiological data. Aspartame is neither a mutagen nor a carcinogen.2Tschanz C Butchko HH Stargel WW Kotsonis FN The clinical evaluation of a food additive: assessment of aspartame. CRC Press, Boca Raton1996Google Scholar The increase in the rate of brain tumours in the USA began before aspartame was marketed, and has actually declined as its use has increased.3National Cancer Institute.Cancer statistics review. National Cancer Institute, 1973–1993Google Scholar Furthermore, this increase has largely been among the elderly population, a pattern which does not correlate with the demographics of aspartame use. The most avid consumers of products that contain aspartame are young to middle-aged adults, among whom the rate of brain tumours has been constant before and after aspartame approval. Modan and colleagues4Modan B Wagener DK Feldman JJ Rosenberg HM Feinleib M Increased mortality from brain tumors: a combined outcome of diagnostic technology and change of attitude toward the elderly.Am J Epidemiol. 1992; 135: 1349-1357Crossref PubMed Scopus (97) Google Scholar conclude that the increase in brain tumours among the elderly is the result of improved detection by more sophisticated imaging techniques, a change in the attitude towards the diagnosis and treatment of disease in the elderly, and access to better healthcare for the elderly. Roberts also ignores the scientific facts when he alleges “severe neuropsychiatric reactions to aspartame”, which he has ostensibly “documented”. In fact, Roberts' documentation consists of his opinions and personal anecdotes. Indeed, the absence of any rigorous scientific methods to back up his opinions has been criticised.5Rolla AR Book review of aspartame (NutraSweet): is it safe? by Roberts HJ.N Engl J Med. 1990; 323: 1495-1496Crossref Google Scholar The results of controlled clinical studies have shown that aspartame is not associated with adverse symptoms, such as headache, seizures, or changes in cognition.2Tschanz C Butchko HH Stargel WW Kotsonis FN The clinical evaluation of a food additive: assessment of aspartame. CRC Press, Boca Raton1996Google Scholar Roberts' allegation of “the probable acceleration of Alzheimer's disease by aspartame products” is nothing more than pure confabulation. That aspartame is not associated with adverse effects, let alone brain tumours, is not surprising since it is quickly metabolised in the gastrointestinal tract to small amounts of common dietary components including the aminoacids, aspartic acid, and phenylalanine. These components are consumed in much greater amounts from common foods, such as milk, meats, fruits, and vegetables. Even at the 90th percentile, daily intake of aspartame is only about 3 mg per kg of bodyweight. Thus, aspartame provides only a small percentage of the usual dietary intake of aspartic acid and phenylalanine.2Tschanz C Butchko HH Stargel WW Kotsonis FN The clinical evaluation of a food additive: assessment of aspartame. CRC Press, Boca Raton1996Google Scholar The safety of aspartame has been extensively documented, and the findings of these studies have been reviewed by expert regulatory scientists worldwide, as well as by the Joint FAO/WHO Expert Committee on Food Additives. The unanimous conclusion is that aspartame is a safe food additive.