The Association Between the Composite Dietary Antioxidant Index and Frailty Symptoms: Mediating Effects of Oxidative Stress

Abstract

Background

There is growing evidence that an antioxidant diet is a protective factor against frailty. However, few studies have examined the effect of comprehensive dietary antioxidants on frailty symptoms. The aim of this study was to examine the relationships between the composite dietary antioxidant index (CDAI) and frailty and the underlying mechanisms involved.

Methods

Based on the National Health and Nutrition Survey (NHANES) 2003–2018, this study included 11,277 older persons aged ≥60 years. In this study, frailty was defined as having a total score >0.21 on the 49-item frailty index. Six dietary antioxidants were selected for use in calculating the CDAI. A weighted multiple logistic regression model with subgroup analysis and restricted cubic splines (RCSs) were used to examine the association between the CDAI and frailty. To examine the role of oxidative stress, mediation analyses were also conducted.

Results

The association between the CDAI score and frailty risk was significant according to the multivariate model. Compared with participants in tertile 1, participants in both tertile 2 and tertile 3 had lower odds of developing frailty symptoms (OR=0.86; 95% CI=0.75–0.97; P=0.02; and OR=0.81; 95% CI=0.70–0.93; P=0.003). According to the subgroup analyses, the differences in interactions were not statistically significant. There was also a potential nonlinear relationship between the CDAI score and frailty risk. The serum albumin concentration and uric acid concentration had significant mediating effects on the association between the CDAI score and frailty index, with 19.25% (P=0.002) and 21.26% (P < 0.001) of the total, respectively.

Conclusion

Frailty is negatively associated with the CDAI score, which may be partially mediated by oxidative stress.

Keywords:

• frailty
• CDAI
• NHANES
• elderly adults

Abbreviations

NHANES, National Health and Nutrition Examination Survey; CDAI, Composite Dietary Antioxidant Index; PA, physical activity; DTAC, dietary total antioxidant capacity; TAC, total antioxidant capacity; NCHS, National Center for Health Statistics; CDC, Centers for Disease Control and Prevention; ORs, odds ratios; CIs, confidence intervals.

Data Sharing Statement

The Data are publicly available on the internet throughout the world (www.cdc.gov/nchs/nhanes/).

Ethics Approval and Informed Consent

This study is exempted from ethics review based on national legislation guidelines, “Notice on the Issuance of Ethical Review Measures for Life Science and Medical Research Involving Humans” National Health Commission’s Department of Health Science, Technology and Education No. 4 (2023).

Acknowledgments

Thanks to the US Centers for Disease Control and Prevention for providing free National Health and Nutrition Examination Survey data for analysis.

Disclosure

The authors report no conflicts of interest in this work.

Additional information

Funding

This work was supported by the Beijing Municipal Natural Science Foundation, China (grant no. 7222082) and the Beijing Municipal Health Commission, China (grant no. 11000023T000002036320). The funding source had no role in the design, methods, subject recruitment, data collections, analysis, and preparation of this paper.