New Aspartame Safety Review ‘Perfectly Predictable’

Statement of CSPI Executive Director Michael F. Jacobson


Considering the reviewers (many industry-friendly researchers) and the sponsor (an aspartame manufacturer), the review’s conclusion that aspartame “is a well-studied sweetener whose safety is clearly documented” was perfectly predictable.

The reviewers wholeheartedly endorsed studies that did not find evidence of carcinogenicity. For instance, a severely flawed epidemiology study—one in which subjects did not consume aspartame until adulthood, and exposure data were highly unreliable—that did not detect an increased cancer risk was “considered to provide definitive information.” Similarly, the review stated that the “acceptance and usefulness of transgenic mouse models in risk assessment is well established.” Tests using such models did not link aspartame to cancer, but, in fact, many toxicologists consider such models to be poor predictors of carcinogenicity.

On the other hand, the reviewers identified every possible flaw in the two studies by Italian researchers that found evidence of carcinogenicity. The studies, published in peer-reviewed, government-sponsored journals, had unacknowledged strengths (long duration, in utero exposure, independently funded), as well as flaws, and hardly warranted the summary statement that they “should be dismissed.”

Considering the weaknesses of studies that raised concerns and did not raise concerns about aspartame, the U.S. National Toxicology Program or other independent agency should retest in well-designed studies this controversial artificial sweetener that is consumed by hundreds of millions of people around the world.

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