The above letter was referred to Dr. Virani and colleagues, who reply in this manner
We appreciate the comments made by Dr. Roberts, who raised the possibility of aspartame-related Graves' disease and pulmonary hypertension. We look forward to the publication of his observations and database. Our literature search failed to reveal any association between autoimmune thyroid disorders and aspartame consumption. The 2 patients presented in our case reports had features consistent with autoimmune thyroid disorders, as manifested by the presence of pretibial myxedema as well as high titers of thyroid-stimulating antibody. Moreover, these patients both denied any intentional weight loss and were not given any dietary counseling as part of the treatment for Graves' disease. We believe that at the time of treatment and subsequent follow-up, they were still consuming the same kind of diet as they had been at the time of diagnosis. Thus far, neither of our patients has had a recurrence of symptoms on follow-up.
Aspartame consumption had initially been linked to neurologic dysfunction, cognitive dysfunction, and allergic reactions. 1–3 Recently, an extensive review failed to confirm most of these early concerns regarding the safety of aspartame. 4 As Dr. Roberts noted, aspartame is metabolized into phenylalanine, aspartic acid, and methanol. The above-mentioned metabolites from aspartame are found in much higher quantities in foods and beverages of daily use. For example, a glass of non-fat milk provides about 6 times more phenylalanine and 13 times more aspartic acid, and a glass of tomato juice provides about 6 times more methanol than does an equivalent volume of beverage sweetened 100% with aspartame. 4
The concern regarding the possible association between aspartame consumption and pulmonary hypertension may be better evaluated by measuring right ventricular systolic pressures (as an indirect measure of pressures in the pulmonary system) by 2-dimensional echocardiography, before and after a test dose of as partame.
Footnotes
Letters to the Editor should be no longer than 2 double-spaced typewritten pages and should contain no more than 4 references. They should be signed, with the expectation that the letters will be published if appropriate. The right to edit all correspondence in accordance with Journal style is reserved by the editors.
References
- 1.Maher TJ, Wurtman RJ. Possible neurologic effects of aspartame, a widely used food additive. Environ Health Perspect 1987;75:53–7. [DOI] [PMC free article] [PubMed]
- 2.Pinto JM, Maher TJ. Administration of aspartame potentiates pentylenetetrazole- and flurothyl-induced seizures in mice. Neuropharmacology 1988;27(1):51–5. [DOI] [PubMed]
- 3.Bradstock MK, Serdula MK, Marks JS, Barnard RJ, Crane NT, Remington PL, Trowbridge FL. Evaluation of reactions to food additives: the aspartame experience. Am J Clin Nutr 1986;43(3):464–9. [DOI] [PubMed]
- 4.Butchko HH, Stargel WW, Comer CP, Mayhew DA, Benninger C, Blackburn GL, et al. Aspartame: review of safety. Regul Toxicol Pharmacol 2002;35(2 Pt 2):S1-93. [DOI] [PubMed]