Association of Nutrient-, Food-, and Lifestyle-Based Oxidative Balance Scores with Liver Enzymes in Older Adults Across Cardiovascular-Risk Groups

Diet and lifestyle are modifiable determinants of oxidative balance through their influence on exposure to antioxidant and pro-oxidant factors. The oxidative balance score (OBS) is a composite index that reflects the balance between these exposures, with higher scores indicating a predominance of antioxidant factors. In this exploratory pilot study, we examined three OBSs (nutrient-, food-, and lifestyle-based), as well as their combined versions (nutrient–lifestyle and food–lifestyle), across clinical subgroups and evaluated their associations with biomarkers of oxidative stress, inflammation, lipid metabolism, and liver-related biomarkers. A total of 44 older adults were enrolled and stratified into three subgroups (16 healthy, 14 hypercholesterolemia, and 14 post–myocardial infarction). Each participant completed a questionnaire, a 3-day food record, and underwent blood sampling. OBSs were calculated based on 15 nutrients, nine food groups, and two lifestyle components. Correlations and multiple linear regression analyses were performed to examine associations between OBSs and the following biomarkers: plasma total antioxidant capacity (TEAC and FRAP), C-reactive protein (CRP), HDL cholesterol, alanine aminotransferase (ALT), and aspartate aminotransferase (AST). The nutrient–lifestyle OBS (OBSN-L) was significantly associated with lower ALT and AST (adjusted ALT β = −1.06; p = 0.048; AST β = −0.54; p = 0.034). A similar association was observed for the nutrient OBS (OBSN) (adjusted AST β = −0.64; p = 0.022). No significant associations were observed for TEAC, FRAP, or CRP. Neither the OBSF nor the OBSF-L was associated with any circulating biomarkers. Higher nutrient-based OBSs, with or without lifestyle integration, were independently associated with lower liver transaminase levels in older adults with varying levels of cardiovascular risk. OBSs may help to capture dietary and lifestyle patterns associated with liver-related biomarkers. These exploratory findings warrant confirmation in larger, prospective studies.