Tsuyoshi Okuhara, Hiroko Okada, Emi Furukawa
Health literacy is one of the most influential concepts in contemporary health promotion. However, its success has created an explanatory shadow. Specifically, complex problems of communication, participation, and engagement are often reduced to deficits in individual health literacy, while relational, organizational, and structural explanations are backgrounded. This paper conceptualized this repetitive explanatory pattern as "health literacy reductionism," the tendency to preferentially translate complex health communication and health promotion problems into a lack of individual health literacy among patients or the public. Drawing on and distinguishing this concept from adjacent critical discussions, including deficit framing, victim blaming, stigma, epistemic injustice, structural approaches, and medicalization, we argued that health literacy reductionism operates as a cross-cutting explanatory logic that can facilitate the reproduction of each of these phenomena. We presented a spectrum that distinguishes valid health literacy explanations from reductionist overextension, together with diagnostic questions for their identification. Four preliminary analytical codes (deficit attribution, presumed incomprehension, omitted alternatives, and design invisibilization) were proposed and applied to the published literature on medication adherence, clinical silence, shared decision-making, and vaccine hesitancy. This study highlighted the implications for research, health promotion, clinical practice, and institutional design.