Despite repeated confirmation of aspartame safety in a variety of foods and beverages, there continues to be interest in researching the potential carcinogenic risk associated with its consumption. The objective of this evaluation was to conduct a systematic assessment of available mechanistic data using a framework for quantitatively integrating the key characteristics of carcinogens (KCCs). For aspartame, 1332 endpoints were appraised for quality and relevance, and quantitatively integrated using an algorithm to determine the potential for individual KCC activity based on all available evidence, and subsequently assessed in the context of human and animal evidence streams. An overall lack of activity (integrated scores <0 and no “strong” categorizations) was observed for all KCCs except oxidative stressor (#5), for which activity was determined to be unlikely to be related to a carcinogenic response. Overall, the KCC-based analysis, together with the lack of consistent evidence of carcinogenicity in experimental animals, continue to support lack of carcinogenicity from aspartame consumption. This comprehensive evaluation of available mechanistic data demonstrates the need for a systematic approach to identify and appraise all avaialble data as part of weight-of-evidence determinations related use of KCC in evaluations of potential human carcinogenicity.
The outcomes of this comprehensive evaluation of available mechanistic data, together with the lack of consistent evidence of carcinogenicity in experimental animals and human observational studies, continue to support lack of carcinogenicity from aspartame consumption.
Consistent with previous evaluations focusing on human and animal cancer specific data including scientific opinions from the European Food Safety Authority (EFSA, 2013), the mechanistic findings assessed in this work suggest aspartame is unlikely to be a human carcinogen. Notably, the overall lack of activity in human models provides support for the lack of carcinogenic findings from epidemiological studies which are associated with lower confidence than the experimental animal studies, given the limitations in exposure and confounding. Overall findings continue to support lack of carcinogenicity from aspartame consumption.
A key strength of this assessment is the systematic approach by which data were identified, appraised, and integrated into an overall carcinogenicity assessment using a framework that provided a flexible, objective, and reproducible process this comprehensive assessment that evaluates key characteristics of carcinogens (KCCs) data in the context of the totality of the evidence provides support for a lack of carcinogenic potential for aspartame noted especially by the lack of genotoxicity and the lack of response in human models.