Association of oxidative balance score with biological aging in US adults: a quantile regression analysis

Background The oxidative stress theory of aging is one of the prominent theories in the field of aging research. The Oxidative Balance Score (OBS) serves as a comprehensive tool for evaluating the effects of different diets and lifestyles on the oxidative/antioxidant system, however, its correlation with biological aging remains ambiguous. We thus conducted this study to explore the relationship between OBS and biological aging in American adults using quantitative measures. Methods We conducted a cross-sectional study using the NHANES 1999–2018 database. We examined several biological aging indicators, including biological age, phenotypic age, telomere length, and serum klotho levels. A weighted multiple linear regression model and smoothed fitted curves were employed to analyze the linear and nonlinear relationship between OBS and biological aging markers. Additionally, quantile regression was utilized to further explore their associations. Results A significant negative correlation was found between OBS and both biological and phenotypic ages, whereas a significant positive correlation was observed between telomere length and serum klotho levels. Upon comparing the highest tertile of OBS with the lowest tertile, the fully adjusted β values for OBS in the highest tertile were − 0.663 (-0.867, -0.458), -1.792 (-2.190, -1.393), and 32.332 (8.193, 56.471) for biological age, phenotypic age, and serum klotho, respectively. Notably, the positive correlation between telomere length [0.031 (0.007, 0.056)] and OBS was significant only in the partially adjusted model. The negative correlation between OBS and biological aging was consistent in individuals aged over 60 years. In quantile regression, the negative correlation between OBS, DOBS, and LOBS was most significant at the 0.93 percentile of biological age and 0.95 percentile of phenotypic age. Moreover, the serum klotho concentration exhibited a positive correlation with LOBS across all quantiles, with the strongest correlation observed at the 0.95 percentile. Conclusions Our study suggests a dose-response relationship between OBS and biological aging, indicating adopting an antioxidant-rich diet and lifestyle may yield beneficial effects on aging. These findings offer theoretical insights into strategies for aging prevention.