Abstract
Objectives
To investigate the association between iodized salt intake and cognitive function in older adults.
Design
A cross-sectional study.
Settings
Individuals from the Zhejiang Major Public Health Surveillance Program (ZPHS).
Participants
Data of 10,217 participants (including 4,680 coastal residents and 5,537 inland residents) aged ≥ 60 years were analyzed.
Measurements
Salt intake was evaluated using a questionnaire, and participants were stratified into the following three groups: iodized salt, non-iodized salt, and mixed salt. Cognitive function was assessed through the Mini-Mental State Examination and defined using education-specific cut-off points. Logistic regression models controlling for an extensive range of potential confounders were generated to examine the association between salt intake and cognitive function among all participants.
Results
Data from 10,217 participants with a 16.1% prevalence of cognitive impairment were analyzed. Compared with non-iodized salt intake, consumption of iodized salt was inversely associated with cognitive impairment (odds ratio [OR], 0.410; 95% confidence interval [CI], 0.351–0.480; P < 0.001) in all participants after multivariable adjustment. An association between iodized salt intake and cognitive impairment was observed in coastal (OR, 0.441; 95% CI, 0.340–0.572; P < 0.001) and inland residents (OR, 0.569; 95% CI, 0.439–0.738; P < 0.001). Despite the insufficient sample size, the results for individuals consuming mixed salt suggested an inverse association between mixed salt intake and cognitive impairment among coastal residents (OR, 0.598; 95% CI, 0.405–0.885; P = 0.010) after multivariable adjustment.
Conclusion
Our results indicate that iodized salt intake may reduce the risk of cognitive impairment in older adults living in coastal or inland areas, and the protective effect of iodized salt intake is greater in coastal areas than in inland areas.
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Acknowledgments
We wish to thank the investigators from the seven selected counties for investigation and data collection. This work was supported by the Medical Health Science and Technology Project of the Zhejiang Provincial Health Commission (grant numbers 2022KY719 and 2022KY722) and the Zhejiang Provincial Public Welfare Technology Application Research Project of China (grant number LGF21H260002). The financial sponsors played no role in the study design/execution, analysis, and interpretation of data, or writing of the manuscript.
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Conflicts of interest: None declared.
Ethical standard: All study participants provided written informed consent before the start of the study. The study protocol was approved by the Ethics Committee of the Zhejiang Provincial Center for Disease Control and Prevention.
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Wu, M.N., Liu, W.F., Li, F.D. et al. Association between Iodized Salt Intake and Cognitive Function in Older Adults in China. J Nutr Health Aging 27, 1005–1011 (2023). https://doi.org/10.1007/s12603-023-1997-7
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DOI: https://doi.org/10.1007/s12603-023-1997-7