Deoxynivalenol (DON), a mycotoxin produced by Fusarium species that infect cereal grains, including wheat, is a significant food safety concern because of its adverse gastrointestinal effects and potential immunotoxicity. In 2015, the Codex Alimentarius Commission of the United Nations set guidelines for maximum allowable DON in wheat and other cereal grains. In this analysis, we employ social network models to analyze global wheat trade patterns in the years before and after the Codex DON guidelines were enacted in 2015: each year from 2012 to 2018 inclusive. Global wheat trading patterns in these seven years all presented hybrid structures: clusters of countries by continent, but a core-periphery structure within each continental cluster. This means that wheat trade, unlike maize and pistachio trade as determined from previous studies, appears to be driven by geographic proximity rather than similarity in food safety regulations. We found no evidence that global wheat trading patterns between nations changed as a result of the Codex DON guidelines, which stands in contrast to our earlier analyses of how aflatoxin regulations affected both maize and pistachio trade worldwide. This may be because insufficient time has passed, or because a single unified DON guideline does not have the same effect as multiple different national-level aflatoxin regulations in changing world food trade. If the central nations in such a global trade structure do not move upon a new policy, it is unlikely that the policy will affect the overall structure of global wheat trade. Without a core-periphery structure and engaged nations in the center of world wheat trade adopting these guidelines, it may take more years yet for these guidelines to be widely adopted, and for populations worldwide to benefit from lower DON exposure in their diets.
This work was supported by the IAFNS Food and Chemical Safety Committee.