BACKGROUND: The prevalence of metabolic syndrome (MetS) among middle-aged and older individuals in the U.S. is rising, posing significant mortality risks. Diet is a key factor in MetS development, yet few studies have examined the combined effects of dietary and lifestyle factors on MetS in this group. Recently, the oxidative balance score (OBS), an indicator of oxidative status encompassing diet and physical activity, has attracted interest. This study explores the association between OBS and MetS, as well as its individual components, in middle-aged and older Americans. METHODS: Data from 6,157 participants aged 45 years and older in the National Health and Nutrition Examination Survey (NHANES) (1999-2018) were analyzed. The OBS was calculated using 16 dietary and four lifestyle factors. Logistic regression was used to assess associations between OBS and MetS. Separate analyses examined dietary OBS (DOBS) and lifestyle OBS (LOBS) in relation to MetS. RESULTS: Higher OBS quartiles were associated with a reduced MetS risk (OR 0.25
95% confidence interval [CI]: 0.12-0.51
CONCLUSION: OBS is inversely associated with MetS in middle-aged and older U.S. adults. Enhancing OBS through dietary guidelines emphasizing antioxidant-rich foods, fiber, and unsaturated fats, alongside lifestyle changes like regular exercise, smoking cessation, and moderate alcohol intake, may be crucial in MetS prevention for this population.