Aspartame is a zero-calorie sugar substitute that has been the subject of much controversy. While the U.S. Food and Drug Administration maintains that the artificial sweetener is safe and has been well-tested, consumer advocate groups, a number of animal studies and some consumer data say otherwise. Both mild side effects and potentially cancer-causing effects of aspartame have been reported through consumer data and animal-based studies.
Use in Moderation During Pregnancy
A 2007 article published in "Environmental Health Perspectives" references a study that found a connection between prenatal aspartame exposure and cancer in rats. However, the study used an amount equivalent to a 150-pound adult consuming 14 packets of aspartame per day. The American Pregnancy Association notes that consuming aspartame in moderation is safe during pregnancy. However, pregnant women with the rare metabolic disorder phenylketonuria, liver disease or high levels of phenylalanine -- a component of aspartame -- in their blood should not use aspartame.
Consumer-Reported Side Effects
A 2003 report completed by the Aspartame Toxicity Information Center documented various consumer-reported toxicity effects of the sweetener. According to the report, aspartame toxicity can be divided into three categories: acute toxicity, which occurs within 48 hours of ingestion; chronic toxicity effects, which occur after years of use; and potential toxicity effects, for which it would be difficult to establish a link to aspartame. The report references a 1988 survey that appeared in the "Journal of Applied Nutrition." According to 551 persons who reported side effects from aspartame, the most common effects were headaches, dizziness, confusion, memory loss, blurred vision, severe depression, irritability, anxiety attacks and severe drowsiness or sleepiness.
The Offical Reports Say it's Safe
A 2002 paper published in "Regulatory Toxicology and Pharmacology" noted that the safety testing of aspartame has gone well beyond the required level and that there are no unresolved questions regarding its safety. Based on a 2005 animal study that found a link between aspartame and lymphomas and leukemia in rats, the National Cancer Institute completed a study examining over half a million retirees and found no connection between the artificial sweetener and the development of lymphoma, leukemia or brain cancer. Finally, a "rigorous review of all available scientific research on aspartame" published in 2013 by the European Food Safety Authority concluded that aspartame, when consumed at recommended doses, is safe.
Consumer Group Disagrees
While the EFSA report found no links between aspartame and cancer, consumer advocate group the Center for Science in the Public Interest notes that these findings are invalid. According to CSPI, the studies analyzed by the EFSA were industry-funded, and three larger, independently funded studies found links between the popular sweetener and cancer. While this link may exist, it should be noted that all clear links between aspartame and cancer have been observed in animal studies only.