ASPARTAME IS NO MORE LIKELY THAN PLACEBO TO CAUSE URTICARIA ANGIOEDEMA - RESULTS OF A MULTICENTER, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED, CROSSOVER STUDY

Background: Anecdotes and single case reports have suggested that the high-intensity sweetener, aspartame, may be associated with allergic/h ypersensitivity-type reactions. Methods: We conducted a multicenter, p lacebo-controlled clinical study to evaluate individuals who had exper ienced urticaria and/or angioedema allegedly associated with ingestion of an aspartame-containing product. Despite extensive recruiting effo rts over 4 years, only 21 subjects could be enrolled. After admission to clinical research units, subjects were given aspartame and placebo in a randomized, double-blind, crossover fashion. Subjects received, o n different days, increasing doses (50, 300, 600 mg) of aspartame and placebo at 8.00 AM, 10.00 AM, and noon. Subjects who weighed less than 40 kg received one half of these doses. Conversion products of aspart ame, aspartylphenylalanine diketopiperazine and beta-aspartame, were a lso included in the aspartame arm of the study. Positive reactions wer e defined as urticaria (hives with wheals 4 mm or more in diameter wit h a collective diameter of at least 15 mm or one or more hives with a wheal of 4 mm or greater with a flare of 8 mm or greater) or as angioe dema. Results: According to these criteria, four reactions were observ ed; two followed aspartame ingestion and two followed placebo ingestio n (p = 1.00). The incidence of other adverse experiences was no differ ent after aspartame versus placebo ingestion (p = 0.289). Conclusion: These results indicate that aspartame and its conversion products are no more likely than placebo to cause urticaria and/or angioedema react ions in subjects with a history consistent with hypersensitivity to as partame.