Dietary isoflavone intake is associated with oxidative stress biomarkers in individuals with cardiometabolic risk

Abstract

Introduction: Oxidative stress plays a central role in the pathophysiology of cardiometabolic diseases (CMDs). Dietary flavonoids, particularly isoflavones, have been asociated with redox balance; however, clinical evidence in populations at cardiometabolic risk remains limited. This study aimed to evaluate the association between flavonoid intake and oxidative stress biomarkers in individuals at cardiometabolic risk. Methodology: A cross-sectional study was conducted in a subsample of 45 adults aged 35–70 years with cardiometabolic risk factors. Dietary intake was assessed using a validated food-frequency questionnaire, and flavonoid consumption was estimated using USDA and Phenol-Explorer databases. Oxidative stress biomarkers—including antioxidant enzymes (SOD, CAT, GPx) and markers of oxidative damage (hydroperoxides, lipid peroxides, AOPPs, and sulfhydryl groups)—were measured in blood samples. Differences across tertiles of isoflavone intake were evaluated using ANOVA. Bivariate correlations and multivariable linear regression models adjusted for sex, age, and BMI were performed. Results: Higher isoflavone intake was associated with lower markers of oxidative damage, particularly AOPP, hydroperoxides, and lipid peroxides, along with lower SOD and GPx activity. Hydroperoxides showed a decreasing trend, while catalase exhibited a nonlinear pattern. Conclusions: These findings support the potential relevance of dietary flavonoids in the context of cardiometabolic health. However, given the study design, causal inferences cannot be drawn.