The association between Oxidative Balance Score and anemia in adults: A cross-sectional population-based study

Oxidative stress is implicated in the pathogenesis of anemia. The Oxidative Balance Score (OBS), a comprehensive metric assessing the combined impact of dietary and lifestyle factors on oxidative stress, has not yet been investigated in relation to anemia prevalence. We conducted a cross-sectional analysis using data from adult National Health and Nutrition Examination Survey participants (2011-2018) were analyzed. The exposure variable, defined as the OBS derived from 20 dietary and lifestyle factors, was evaluated against anemia status using multivariable logistic regression. Additional analytical approaches-including stratified subgroup analyses, interaction tests and restricted cubic spline (RCS) modeling were implemented to investigate potential associations. Our final sample included 12,977 participants. Fully adjusted models demonstrated 30% and 31% lower odds of anemia for the highest tertile of overall OBS (odds ratio = 0.70, 95% confidence interval: 0.55-0.88, P < .01) and dietary OBS (odds ratio = 0.69, 95% confidence interval: 0.54-0.87, P < .01), respectively, compared to the lowest tertile. The inverse OBS-anemia association remained consistent across most demographic and clinical subgroups, with education level, serum iron, and mean corpuscular volume identified as significant effect modifiers (P for interaction < .05). RCS modeling established linear exposure-response associations (P for nonlinearity > .01), and sensitivity analyses confirmed the robustness of our results. The study found that higher OBS is associated with lower anemia prevalence, highlighting the potential for future prospective research into dietary strategies for this condition.