Iron, Zinc and Copper from Cereal Food Sources and Cognitive Performance in Older Adults in China

BACKGROUND: We aimed to determine the risk factors associated with cognitive performance in older adults in China. METHODS: A longitudinal study was conducted in a group of 1,898 adults aged 60 yr and over in China, Cognitive score was determined by a modified Telephone Interview for Cognitive Status (TICSM). The dietary intake of iron (Fe), zinc (Zn) and copper (Cu) from cereal source foods (CSF) were calculated by using Food Frequency Questionnaire (FFQ) and Chinese Food Composition Tables. Descriptive statistics and multivariate mixed regression models were utilized to explore the association between the intake of these elements and cognitive function. RESULTS: The mean dietary intakes of Fe, Zn and Cu from CSF were 12.01, 6.90 and 1.30 mg/d respectively. Compared with participants in the high-cognitive group, those in the low-cognitive group had lower total dietary intakes of Fe, Zn and Cu. However, with respect to ratios of CSF-Zn, CSF-Fe and CSF-Cu to their respective total values, participants in the low-cognitive group had significantly higher ratios than those in the high-cognitive group. The results of multivariate mixed regression model revealed that although total dietary Zn intake was positively linked with cognitive function, the CSF-Zn/Zn ratio was negatively associated with cognitive performance. CONCLUSION: Excessive intake of Zn from a specific food source, such as CSF, was found to be negatively associated with cognitive status. Avoiding over-intake of Zn from CSF foods and diversifying intake of Zn from different food sources seemed to protect individuals from cognitive decline.