New Study of Aspartame Research Reaffirms Safety, Even Among Heaviest Users

12/09/07 A new review of aspartame research -- the most comprehensive ever conducted -- once again has concluded the widely used sugar substitute is safe, even among its heaviest users.

The review, "Aspartame: A Safety Evaluation Based on Current Use Levels, Regulations, and Toxicological and Epidemiological Studies," published in the September issue of Informa Healthcare's Critical Reviews in Toxicology (Volume 37, Issue 8, pp. 629-727), also identified serious flaws in two recent European studies that claimed to find a link between aspartame and cancer in rats.

The 98-page, peer-reviewed evaluation was carried out by a panel of eight internationally recognized scientists. It considered more than 500 studies, articles and reports conducted over the last 25 years on the health effects of aspartame, including unpublished works submitted to the Food and Drug Administration and the Department of Health and Human Services for regulatory approvals of the ingredient. The study was conducted in a manner that is consistent with the Food and Drug Administration process for evaluating new food ingredients before entry into the marketplace.

"The weight of existing evidence is that aspartame is safe at current levels of consumption...," the experts concluded. "No credible evidence was found that aspartame is carcinogenic, neurotoxic, or has any other adverse effect on health when consumed even at quantities many times the established ADI [Acceptable Daily Intake] levels."

As part of its review, the panel applied the most recent food consumption survey information to estimate current aspartame intake. Despite its popularity, the average among those who use the sweetener is very low, only 4.9 milligrams per kilogram of body weight daily, a fraction of the government-approved upper intake level of 50 milligrams per kilogram per day.

"Because aspartame use has increased dramatically over the years, the panel made a special effort to review the most up-to-date consumption data," said Bernadene A. Magnuson, PhD, a University of Maryland food toxicologist who coordinated the panel for the Burdock Group of Vero Beach, Florida. "It found that today's use, even by high users in special subgroups, remains well below acceptable levels."

The studies reviewed by the panel looked at aspartame's potential effect on behavior, reproductive health, neurological functions, and cancer and tumor development. They covered individuals with Parkinson's disease and diabetes; those suffering from allergies, depression and seizures; and various categories of children, including those with hyperactivity or claiming to be sensitive to sugar.

"The suggestions of adverse effects from aspartame consumption have absolutely no credible scientific basis," said William J. Waddell, MD, Professor and Chair, Emeritus, Toxicology, at the University of Louisville School of Medicine, who chaired the panel. "It is safe for all population groups."

The panel also considered recent highly publicized studies by the Italian Ramazzini group that purported to show a link between aspartame and cancer in rats. "Multiple expert evaluations, as well as our work, identified numerous flaws in the Italian studies," said Magnuson. "After careful review, our panel remains completely confident in aspartame safety."

The review panel spent 11 months looking at past research on aspartame, which entered the food supply in 1981 and is used in more than 6,000 food products worldwide, including most diet soft drinks and many sugar-free chewing gums.

The safety review was structured in a unique manner. Dr. Waddell, on behalf of the Burdock Group, selected members to achieve representation of the complete spectrum of toxicological expertise relevant to aspartame. The identity of the sponsor, Ajinomoto, was unknown to the chair and expert panelists throughout the conduct and completion of the review, and submission and peer review of the manuscript. Panelist identity also remained unknown to the sponsor. There were no known conflicts of interest with the sponsor or potential biases of the authors.

Other members of the expert panel were John Doull of the University of Kansas Medical Center; the late Robert Kroes of the University of Utrecht, The Netherlands; Gary M. Marsh of the University of Pittsburgh; Michael W. Pariza of the University of Wisconsin; Peter S. Spencer of the Oregon Health and Science University; Ron Walker of the University of Surrey, United Kingdom; and Gary Murray Williams of New York Medical College. Their specialties, in addition to pharmacology and toxicology, include microbiology, biostatistics, and risk assessment.