The Food and Drug Administration should immediately review the safety of the artificial sweetener aspartame, and possibly ban it, in light of a new study published in the European Journal of Oncology. The study, conducted in Italy, found statistically significant increases in lymphomas and leukemias among female rats given aspartame. The smallest amount of aspartame (20 milligrams per kilogram of body weight) that caused a significant increase in cancer incidence is in the ballpark of what many people consume. The study also found equivocal results regarding brain tumors.

At a minimum, the government should conduct new animal studies of aspartame and encourage consumers and manufacturers that use artificial sweeteners to switch to sucralose, which CSPI considers to be the safest of the several artificial sweeteners on the market.

Aspartame, also sold as Equal and NutraSweet, is used in Diet Coke, Diet Pepsi, and thousands of other foods and is consumed by 200 million people in the United States and around the world, according to the industry's Calorie Control Council.

"The FDA immediately should ask the government's National Toxicology Program to conduct new animal studies to assess the cancer risk from aspartame. As a precautionary measure, in the several years it would take to design and conduct such studies, the FDA should consider ordering aspartame off the market," said CSPI executive director Michael F. Jacobson. "Despite several shortcomings in the new study, one notable plus is that it was designed and conducted independently. Virtually all of the previous research was sponsored by the makers of aspartame."

(In 1996, the Minneapolis Star Tribune reported that the FDA repeatedly stopped the National Toxicology Program from conducting lifetime animal tests of aspartame.)

The authors of the Italian study call for "urgent re-examination of permissible exposure levels of [aspartame] in both food and beverages, especially to protect children."

CSPI has long urged that aspartame be better tested, but has not maintained that the artificial sweetener is harmful, except to some people in whom it causes headaches. The California Environmental Protection Agency has also called for further studies on aspartame.