Not So Sweet: Cancers in rats that consumed aspartame

A large, new test in rats suggests that the artificial sweetener aspartame may be a carcinogen. But scientists not affiliated with the research express doubts about the study’s validity and point to earlier trials that produced the opposite result.

Aspartame, sold under the brand names Equal and NutraSweet, is used in thousands of products, including diet soft drinks and sugarfree gum.