The Food and Drug Administration (“FDA”) has rejected two citizen petitions that called for regulators to ban the low-calorie sweetener aspartame.  In the denial letters, the agency stated that the anecdotal adverse effects cited by petitioners were “not supported by scientific evidence” and did “not provide a basis for revoking the regulation pertaining to aspartame.”

Aspartame is an artificial sweetener used as a sugar substitute in some foods and beverages; it is approximately 200 times as sweet as table sugar. It is an ingredient in various coffee sweeteners, as well as popular soft drinks. One petition claimed that aspartame causes seizures and tumors. The petition also alleged that aspartame negatively interacts with various prescription drugs and that consuming aspartame results in harmful production of methanol inside the body. The other petition claimed that some of the original research used in the application for FDA approval of aspartame was fraudulent.

In response, the FDA outlined the approval process that aspartame was originally subjected to, and cited to additional studies that have been completed since the ingredient’s approval. The FDA explicitly stated that none of the studies that were completed either before or after aspartame’s approval provided any evidence to alter the agency’s conclusion about the safety of aspartame. In the course of responding to these petitions, the FDA completed a literature search of recent toxicological information on aspartame as well. The results of this search “showed that there was no new information that would raise concerns regarding the safety of aspartame.”

The FDA also shot down specific claims, noting that methanol in aspartame (or in fruits and juices, where the chemical is found naturally) does not accumulate in the body and is “easily metabolized” by the body. The FDA concluded its response by emphasizing that the safety of aspartame has been reviewed repeatedly, not only in the United States, but also by regulatory authorities in Canada, the United Kingdom, Australia, Europe, and Japan. All of these authorities agree “that aspartame is safe for the general population.”

The two petitions and related denial letter responses from the FDA, one to Ms. Betty Martini, and one to Mr. Paul Stroller, MD, can be accessed at