Regulatory divergence in synthetic food dye governance in Mexico and its public health implications

Synthetic food dyes are widely used in processed and ultra-processed foods (UPFs), particularly in products marketed to children. In Mexico, these products represent a substantial share of dietary intake, raising concerns about population-level exposure to non-essential additives. Regulatory approaches to synthetic food dyes vary across countries, reflecting differing interpretations of scientific evidence and precautionary frameworks. The scientific literature on their health effects remains heterogeneous. While experimental and clinical sties generally report modest and inconsistent effect sizes, systematic reviews have identified recurring associations between certain dyes and neurobehavioral outcomes in children, particularly among susceptible subgroups. Uncertainties persist regarding causal mechanisms, cumulative exposure, and real-world intake levels. This comment examines how scientific uncertainty, exposure patterns, and regulatory frameworks interact to shape policy responses. Using Mexico as a case study, it highlights how regulatory differences may contribute to variation in product formulation, labeling practices, and potential population exposure. The 2026 national decision to withdraw the authorisation of erythrosine, reached through a domestic exposure assessment, illustrates how such determinations depend on country-specific data and on how the burden of uncertainty is allocated, raising broader challenges for food governance under uncertainty. Synthetic food dyes remain widely present in ultra-processed foods sold in Mexico, particularly in products marketed to children. Comparable branded products show differences in formulation across markets, reflecting variation in regulatory approaches and potential differences in population exposure. Strengthening transparency, periodic review of additives, and child-focused regulatory measures may support more consistent consumer protection under conditions of scientific uncertainty. Mexico's 2026 withdrawal of erythrosine authorisation, based on a domestic exposure assessment, shows that national regulatory decisions depend on country-specific exposure data rather than on alignment with other jurisdictions.