Dietary habits and selenium, glutathione peroxidase and total antioxidant status in the serum of patients with relapsing-remitting multiple sclerosis

BACKGROUND: Dietary habits and adequate dietary intake of antioxidants in the diet may be one of the most important environmental factors for the prevention of Multiple Sclerosis (MS). OBJECTIVES: The aim of this study was to estimate selenium (Se) concentration, glutathione peroxidase (GSH-Px) activity and total antioxidant status (TAS) in the serum of patients with MS and the influence of dietary habits on the status. METHODS: 101 patients with relapsing-remitting MS (aged 18-58 years), as well as control group of 63 healthy people (aged 19-65 years) were studied. Food-frequency questionnaires were implemented to collect the dietary data. Se concentration in the serum samples was determined by atomic absorption spectrometry. GSH-Px activity and TAS in examined serum was measured using the ready-made sets of tests by Randox Laboratories Ltd., UK. RESULTS: Serum Se concentration and GSH-Px activity in the serum of patients with MS (55.2±16.2 μg/L, 6676.1±2386.4 U/L; respectively) were significantly decreased (p<0.01, p<0.05; respectively) compared with control group (79.2±20.6 μg/L, 8029.9±2650.1 U/L; respectively). A significant correlation (r=0.39, p<0.01) was observed between Se concentration and GSH-Px activity in the serum of examined patients. TAS value in the serum of patients with MS (1.03±0.37 mmol/L) was also significantly lower (p<0.01) than in healthy volunteers (1.48±0.41 mmol/L). Frequent consumption of poultry, bakery products, pulses and fish seemed to increase serum Se concentration in the group of patients; whereas frequent consumption of butter, wholegrain bread, sweet beverages and sugar was found to accompany with lower values of Se in the serum. We have observed significant decrease TAS (p<0.05, p<0.01; respectively) in the serum of smokers and those patients who received immunomodulatory drugs (0.95±0.39 mmol/L, 0.92±0.34 mmol/L; respectively) compared with no-smoking patients and not taking immunomodulators (1.14±0.33 mmol/L, 1.31±0.31 mmol/L; respectively). CONCLUSIONS: Serum Se concentration, GSH-Px activity and TAS value were significantly lower in patients with relapsing-remitting MS compared with healthy volunteers. Dietary habits have a significant influence on Se status. Smoking cigarettes and intake of immunomodulatory drugs therapy have a negative impact on TAS of examined patients.