Association Between Dietary Copper Intake and Cognitive Decline: A Perspective Cohort Study in Chinese Elderly

Objective: The association between dietary copper (Cu) intake and cognitive decline remains uncertain. We aim to investigate the longitudinal association of dietary Cu with cognitive decline in Chinese elderly. Methods: A total of 3,106 Chinese adults aged older than or equal to 55 years from China Health and Nutrition Survey (CHNS) were included. Dietary nutrients information was collected by 24-hours dietary recalls in combination with a food-weighted method. The 5-year change rates in global or composite cognitive scores based on a subset of items from the Telephone Interview for Cognitive Status-modified (TICS-m) was calculated as the last-survey score minus the baseline score, then divided by the follow-up time (unit, years) and multiplied by five. Results: The median follow-up duration was 5.9 years. There was a nonlinear association of dietary Cu intake with the 5-year change rates in global or composite cognitive scores, with the inflection point at approximately 1.3 mg/day of dietary Cu intake. Accordingly, for the composite cognitive score, compared to the first quantile (<1.28 mg/day), those with dietary Cu in quantiles 2-8