The joint association of biological aging and dietary oxidative balance score with cardiometabolic multimorbidity among U.S. older adults

OBJECTIVES: The risk of cardiometabolic multimorbidity (CMM) increases with age, making it a growing public health concern. Biological aging, represented by accelerated biological aging (PhenoAge), reflects physiological decline, while dietary oxidative stress is closely linked to chronic disease development. This study explores the combined association of PhenoAge acceleration and the Dietary Oxidative Balance Score (DOBS) with CMM, a condition comprising stroke, heart disease, and type 2 diabetes. METHODS: Utilizing data from 10,770 participants aged 60 years and older from the National Health and Nutrition Examination Survey (NHANES) 2003-2018, we examined the separate and interactive associations of DOBS and PhenoAge acceleration with the prevalence of CMM. Biological aging was assessed using the PhenoAge algorithm by various markers, with acceleration determined by the difference between PhenoAge and chronological age. DOBS was calculated from 16 nutrients based on two 24-h dietary recalls. We assessed single and combined associations between PhenoAge acceleration and DOBS with CMM using multivariate logistic regressions and restricted cubic spline models. Then we assessed the addictive interaction association of PhenoAge acceleration and DOBS with CMM. Subgroup analyses by age, sex, race, and BMI were also performed. RESULTS: Our results demonstrate that participants with both accelerated PhenoAge and a pro-oxidative diet had a significantly higher prevalence of CMM compared with those with neither factor. The association between joint exposure and CMM remained statistically significant after full adjustment (OR = 6.96, 95% CI: 4.83-10.04, P < 0.001), and the joint exposure group consistently exhibited the highest risk of CMM. For additive interaction, no statistically significant addictive interaction was observed between accelerated PhenoAge and a pro-oxidative diet. Sensitivity analysis using an alternative DOBS classification yielded consistent results. In subgroup analyses, significant additive interaction was observed in females and individuals with obesity (BMI ≥ 30). CONCLUSIONS: Low DOBS and accelerated PhenoAge were jointly associated with a higher likelihood of CMM among U.S. older adults, highlighting the potential relevance of dietary oxidative balance and biological aging in cardiometabolic multimorbidity.