Aspartame was administered in the diet of rats at concentrations of 100,000, 50,000, 10,000, 2,000, 400, 80, or 0 ppm, beginning at eight weeks of age and continuing until death. A dose-related increase was seen in the incidence of various cancers (including lymphoma/leukemia, transitional cell carcinoma of the renal pelvis and ureter, and malignant schwannoma). Significant increases were seen in females in the incidence of lymphoma/leukemia and transitional cell carcinoma of the renal pelvis and ureter, beginning at a dose of 400 ppm.
The authors of the study concluded that aspartame is a multipotential carcinogen, even at a daily dose of 20 mg/kg of body weight, which is much lower than the official acceptable daily intake.
This study adds to the list of potential adverse effects of this commonly used artificial sweetener. Previous reports have indicated that aspartame ingestion can cause epileptic seizures, migraines, urticaria, eye pain, depression, or fibromyalgia in susceptible people.
However, the makers of aspartame should not be dismayed that no self-respecting nutritionist can recommend their product as a sugar substitute. Recent anecdotal evidence that aspartame is an effective ant poison (it wipes out carpenter ants and fire ants; see http://www.proliberty.com/observer/20060612.htm) should help counterbalance any loss of sales that might result from the idea that this chemical causes cancer in humans.
Soffritti M, et al. First experimental demonstration of the multipotential carcinogenic effects of aspartame administered in the feed of Sprague-Dawley rats. Environ Health Perspect. 2006;114:379-385.
Reprinted with exclusive permission from The Townsend Letter. Sept 2007