Evaluation of the association between the healthy eating index and the level of serum and dietary intake of copper and zinc

Abstract

BackgroundHealthy behaviors, such as a healthy diet are associated with a reduced risk of several chronic diseases. We aimed to investigate the association of dietary quality, assessed using the Healthy Eating Index (HEI), with serum copper (Cu) and zinc (Zn) and also dietary intake of Cu and Zn. Study designThis cross-sectional study was performed in a sub-sample of 5313 participants (2162 males and 3151 females) aged 35–65 years recruited as part of MASHAD cohort study. MethodsHEI was assessed using dietary intake data that were collected based on a 65 items food frequency questionnaire (FFQ). Flame atomic absorption spectrometry was used to measure serum Cu and Zn concentrations. Dietary intakes of Cu and Zn were evaluated based on the FFQ data; they were adjusted for total energy. ResultsHEI values had a negative correlation with serum Cu concentration and positive correlation with dietary intake and serum Zn/Cu showed. After adjusting for confounding factors, results showed that with increasing 10 unit of HEI the risk of serum level of Cu < 70 μg/dl (male)/<80 μg/dl (female) 1.09-fold increases in comparison to reference group (70–140 μg/dl [male]/80–155 μg/dl [female]). Moreover, after adjusting for confounding factors, a significant association was found between serum Zn/Cu and HEI (β = 0.003; 95%CI = 0.002–0.005; p < 0.001) but this association was not significant for dietary intake Zn/Cu. ConclusionThere was a negative and positive correlation between HEI and serum concentration of Cu and serum Zn/Cu, respectively in the middle-aged Iranian adults. Although, the association between serum concentrations of Zn and Cu with their dietary intake were not significant. The evaluation of these factors in a larger population and in cohort study design may help further confirm these findings.