Association between suicidal ideation and oxidative balance score (OBS): National Health and Nutrition Examination Survey (NHANES) 2005-2018

Background: The oxidative balance score (OBS) serves as an indicator of systemic oxidative stress status, where a higher OBS indicates significant exposure to antioxidants through dietary and lifestyle choices. Studies exploring the relationship between OBS and suicidal ideation are limited. Therefore, this study aimed to examine the association between OBS and suicidal ideation. Methods: This cross-sectional study selected 28,598 individuals aged >= 20 years from the 2005-2018 National Health and Nutrition Examination Survey dataset. The OBS was determined using 16 dietary components and 4 lifestyle components. Item 9 of the Patient Health Questionnaire-9 was used to evaluate suicidal ideation. The association between suicidal ideation and OBS, dietary OBS, and lifestyle OBS was examined using weighted logistic regression and restricted cubic spline. The subgroup analyses and interaction tests were further conducted to assess the robustness of these associations across different populations. Results: The prevalence of suicidal ideation was 3.35 %. OBS, dietary OBS, and lifestyle OBS were substantially and inversely linked with suicidal ideation in Models 1, 2, and 3 (p < 0.05). The odds ratio for the highest quartile (Q4) of these variables and suicidal ideation in Model 3 was 0.44 [95 % confidence interval (CI): 0.30-0.65], 0.54 (95 % CI: 0.37-0.78), and 0.50 (95 % CI, 0.34-0.74), respectively, compared with the lowest quartile (Q1). The subgroup analyses revealed consistent connections between the three oxidative stress indices and suicidal ideation. The lifestyle OBS was negatively correlated with suicidal ideation, especially in women (p for interaction < 0.05). Conclusions: The dietary and lifestyle OBSs may influence suicidal ideation by modulating oxidative balance. An antioxidant diet and lifestyle are crucial in mitigating suicidal ideation. These findings suggest a potential sex-specific suicide ideation risk, which significantly correlates with suicidal ideation in women but not in men.