WHO's Cancer Agency to List Aspartame as a 'Possible Carcinogen'

The ruling will be the first to declare the artificial sweetener — aspartame — as possibly carcinogenic and will likely lead to backlash from the food industry.

According to a Reuters exclusive report, aspartame, an artificial sweetener used in many foods and beverages, is expected to be listed as "possibly carcinogenic to humans" in July by the WHO's International Agency for Research on Cancer (IARC).

The agency finalized the ruling in early June after evaluating 1,300 studies to determine whether the popular artificial sweetener has possible cancer-causing effects.

The IARC will release its evaluations on July 14.

The ruling means that limited evidence exists suggesting a link between aspartame and cancer but does not take into account how much aspartame is safe to consume.

However, also on July 14, another WHO committee, the Joint Expert Committee on Food Additives (JECFA), is expected to announce the results of its review on the artificial sweetener, possibly including assessments on acceptable daily dietary exposures.

According to the Reuters report, "An IARC spokesperson said both the IARC and JECFA committees' findings were confidential until July, but added they were 'complementary,' with IARC's conclusion representing 'the first fundamental step to understand carcinogenicity.'"

The IARC's labeling of aspartame as a possible carcinogen in July follows a May 15 WHO announcement warning consumers to avoid artificial sweeteners for weight control.

IARC decisions are influential and have previously led to lawsuits and upheaval among industry leaders and regulators. Past rulings have also confused the public about the safety of many commonly used products.

In a news release, Kate Loatman, executive director of the International Council of Beverages Associations, says, "[…] public health authorities should be deeply concerned that this leaked opinion contradicts decades of high-quality scientific evidence and could needlessly mislead consumers into consuming more sugar rather than choosing safe no- and low-sugar options - all on the basis of low-quality studies."

Still, according to Reuters sources, the IARC's objective when listing aspartame as a possible cancer-causing compound is to spark new research that hopefully provides more conclusive evidence.