Defying Dietary Homogeneity: Stable Isotopes in Hair Reveal Persistent Geographic Heterogeneity in Argentina's Modern Diet

Abstract

Objectives: The main objective of the study is to characterize and test the hypothesis of a continuing trend toward homogenization in contemporary Argentine diet through stable isotope analysis, exploring regional variation in the context of globalized food systems. It is expected that the distribution of stable isotopes will exhibit a limited range of values but still display some heterogeneity that allows differentiation of dietary patterns by region. Methods: A total of 204 hair samples were collected from volunteer donors in Argentina and analyzed for the stable isotopes δ13C, δ15N, and δ34S. Statistical analyses and isotopic niche modeling using Bayesian ellipses were performed to determine dietary differences between regions and geographical factors influencing the distribution of stable isotopes. The ranges of variations in dietary choices (omnivores, vegetarians, and vegans) were also characterized. Results: The analyses revealed significant differences in stable isotope values between regions, indicating that interregional heterogeneity in diet persists despite globalization and previous trends. Significant correlations were found between isotopic values and geographic variables. It was determined that δ13C and δ15N values vary significantly between omnivores, vegetarians, and vegans, allowing for the identification of differential consumption of proteins at an isotopic level. Conclusions: The study concludes that the contemporary Argentine dietary pattern is consistent with the global trend toward “delocalized” and “deseasonalized” diets, where global foods are produced locally. The study suggests that the homogenization process has not completely eliminated regional dietary particularities, as the effective incorporation into diets is mediated by cultural, economic, and logistical factors.