Dietary habits; concentration of copper, zinc, and Cu-to-Zn ratio in serum and ability status of patients with relapsing-remitting multiple sclerosis

Objective: Dietary habits and adequate intake of antioxidants in the diet-for example, copper (Cu) and zinc (Zn)-may be an environmental factor in the occurrence of multiple sclerosis (MS). The aim of this study was to estimate the influence of dietary habits on the concentration of Cu, Zn in the serum, and the effect of Cu-to-Zn ratio on the ability status of patients with relapsing remitting MS. Methods: This was an observational case-control study that included 101 individuals with MS and 68 healthy individuals (controls). Food frequency questionnaires were used to collect dietary data. Serum concentrations of Cu and Zn were determined by the electrothermal and flame atomic absorption spectrometry method, respectively. The ratio of Cu to Zn was calculated and compared with the Expanded Disability Status Scale of patients. Results: The concentration of Zn was significantly lower in the serum of individuals with MS (0.776 +/- 0.195 mg/L) than in the control group (0.992 +/- 0.315 mg/L). The ratio of Cu to Zn was higher in the examined patients (1.347 +/- 0.806) than in the healthy volunteers (1.012 +/- 0.458). Lower ability status (P < 0.05) was revealed in patients with an abnormal ratio of Cu to Zn, particularly, in cerebellar function, pyramidal tracts, and emotional conditions. Selected dietary habits have a significant influence on Cu and Zn concentration in the serum of patients with MS. Conclusions: Lower serum concentrations of Zn and higher ratio of Cu to Zn in patients with MS can suggest a relationship between MS and oxidative stress. Products that are a source of Zn should be included in the diet, which can improve the clinical condition of people with MS. (C) 2017 Elsevier Inc. All rights reserved.