Agricultural Intensification and the Allergenic Source Term: A Hypothesis Linking Nitrogen Input to Rising Peanut Allergy Prevalence

The prevalence of peanut (Arachis hypogaea) allergy has risen markedly over the late twentieth and early twenty-first centuries, particularly in industrialized nations. Dominant explanatory models have focused on changes in human immune development, such as the hygiene hypothesis, or on post-harvest processing effects, particularly thermal modification during roasting. This paper proposes an additional, upstream variable: a change in the biochemical composition of the peanut itself driven by modern agricultural practices. We advance a Source Term Hypothesis, suggesting that the transition from low-input cultivation in nitrogen-limited soils to intensive NPK fertilization regimes has increased the absolute concentration of nitrogen-rich seed storage proteins, including the major peanut allergens Ara h 1, Ara h 2, and Ara h 3. Even in the absence of altered human immune sensitivity, an increased allergenic protein density per unit mass of peanut would raise exposure flux, potentially lowering thresholds for sensitization and clinical reactivity at the population level. We outline the biochemical rationale for this hypothesis, address potential objections, and propose experimental approaches for its verification.