The dangers of aspartame have received significant publicity in recent years. One study, in particular, that was published in the Environmental Health Perspectives (EHP) journal, suggests that aspartame causes cancer in rats at levels currently approved for humans.
EHP is published by the National Institute of Environmental Health Sciences, part of the U.S. Department of Health and Human Services.
According to the report, a statistically significant increase in the incidence of malignant tumors, lymphomas and leukemia in rats exposed to varying doses of aspartame appears to link the artificial sweetener to a high carcinogenicity rate.
The authors of the study, the first to demonstrate multi-potential carcinogenic dangers of the sweetener administered to rats in feed, called for an "urgent reevaluation" of the current guidelines for the use and consumption of this compound.
Currently, the acceptable daily intake for humans is set at 50 mg/kg in the United States and 40 mg/kg in Europe.
Aspartame is the second most widely used artificial sweetener in the world. It is found in more than 6,000 products including carbonated and powdered soft drinks, hot chocolate, chewing gum, candy, desserts, yogurt, and tabletop sweeteners, as well as some pharmaceutical products like vitamins and sugar-free cough drops.
Despite mounting evidence of the dangers of aspartame, more than 200 million people worldwide consume it.
The sweetener has been used for more than 30 years, having first been approved by the FDA in 1974. Studies of the carcinogenicity of aspartame performed by its producers have been negative.
Researchers administered aspartame to Sprague-Dawley rats by adding it to a standard diet. They began studying aspartame in rats at 8 weeks of age and continued until the spontaneous death of each rat.
Treatment groups received feed that contained concentrations of aspartame at dosages simulating human daily intakes of 5,000, 2,500, 500, 100, 20, and 4 mg/kg body weight. Groups consisted of 100 males and 100 females at each of the three highest dosages and 150 males and 150 females at all lower dosages and controls.
The experiment ended after the death of the last animal at 159 weeks. At spontaneous death, each animal underwent examination for microscopic changes in all organs and tissues, a process different from the aspartame studies conducted 30 years ago and one that was designed to allow aspartame to fully express any carcinogenic potential.
The treated animals showed dangers of aspartame with extensive evidence of malignant cancers including lymphomas, leukemias, and tumors at multiple organ sites in both males and females.
The authors speculate the increase in lymphomas and leukemias may be related to one of the metabolites in aspartame, namely methanol, which is metabolized in both rats and humans to formaldehyde. Both methanol and formaldehyde have shown links to lymphomas and leukemias in other long-term experiments by the same authors.
The authors of the study were Morando Soffritti, Fiorella Belpoggi, Davide Degli Esposti, Luca Lambertini, Eva Tibaldi, and Anna Rigano of the Cesare Maltoni Cancer Research Center, European Ramazzini Foundation of Oncology and Environmental Sciences, Bologna, Italy.
Funding for the research was provided by the European Ramazzini Foundation of Oncology and Environmental Sciences, Bologna, Italy. The full article is available at www.ehponline.org.