Mayara Lopes Martins1, Angela Teodósio da Silva1, Roberta Pieri Machado1, Hanna Pillmann Ramos2,3, Caroline Martinelli4, Taís Thomsen Silveira1,3, Edson Luiz da Silva1,2,3, Elisabeth Wazlawik5,6,7. 1. Postgraduate Program in Nutrition, Federal University of Santa Catarina, Florianópolis, SC, Brazil. 2. Department of Pharmacy, Federal University of Santa Catarina, Florianópolis, SC, Brazil. 3. Laboratory of Lipids, Antioxidants, and Atherosclerosis, Department of Clinical Analyses, Federal University of Santa Catarina, Florianópolis, SC, Brazil. 4. Department of Nutrition, Federal University of Santa Catarina, Florianópolis, SC, Brazil. 5. Postgraduate Program in Nutrition, Federal University of Santa Catarina, Florianópolis, SC, Brazil. e.wazlawik@ufsc.br. 6. Department of Nutrition, Federal University of Santa Catarina, Florianópolis, SC, Brazil. e.wazlawik@ufsc.br. 7. Programa de Pós-Graduação em Nutrição, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina, Campus Universitário, Rua Delfino Conti, Trindade, Florianópolis, SC, 88040-900, Brazil. e.wazlawik@ufsc.br.
Abstract
PURPOSE: Whey protein has antioxidant properties through its amino acid cysteine, which enhances the biosynthesis of glutathione, the most abundant antioxidant non-protein in mammalians. Glutathione influences vitamin C recycling and increases its protective effect on oxidative stress (OS). The aim of this study was to analyse the effect of whey protein and vitamin C supplementation on OS biomarkers in chronic haemodialysis (HD) patients. METHODS: This pioneer trial was a randomised, double-blind, pilot study in patients from a dialysis clinic. Patients were randomised into three groups (1:1:1) and stratified by HD frequency (2 or 3 times/week). Sachets containing protein powder (20.0 g) with/without vitamin C (0.25 g) or placebo (20.0 g of white rice flour) with vitamin C (0.25 g) were supplemented after each HD session, 3 times/week for 8 weeks. Blood samples were collected at the baseline period and after 8 weeks for the measurement of reduced glutathione (GSH), oxidised glutathione (GSSG), the GSH:GSSG ratio, malondialdehyde, vitamin C, and glutathione peroxidase-1. RESULTS: Twenty-two patients were enrolled, of which 18 concluded the trial, 6 per group (18.2%, n = 4 losses during follow-up). The vitamin C group presented decreased GSH levels after supplementation (p = 0.053) and a decreasing tendency in the GSH:GSSG ratio (non-statistically significant), while MDA levels significantly decreased only in the whey protein-supplemented groups (p ≤ 0.05). CONCLUSION: The results suggest a pro-oxidant effect of 0.25 g of vitamin C alone in chronic HD patients. CLINICAL TRIAL REGISTRATION: https://ensaiosclinicos.gov.br/ , RBR-65b8f4.
PURPOSE: Whey protein has antioxidant properties through its amino acid cysteine, which enhances the biosynthesis of glutathione, the most abundant antioxidant non-protein in mammalians. Glutathione influences vitamin C recycling and increases its protective effect on oxidative stress (OS). The aim of this study was to analyse the effect of whey protein and vitamin C supplementation on OS biomarkers in chronic haemodialysis (HD) patients. METHODS: This pioneer trial was a randomised, double-blind, pilot study in patients from a dialysis clinic. Patients were randomised into three groups (1:1:1) and stratified by HD frequency (2 or 3 times/week). Sachets containing protein powder (20.0 g) with/without vitamin C (0.25 g) or placebo (20.0 g of white rice flour) with vitamin C (0.25 g) were supplemented after each HD session, 3 times/week for 8 weeks. Blood samples were collected at the baseline period and after 8 weeks for the measurement of reduced glutathione (GSH), oxidised glutathione (GSSG), the GSH:GSSG ratio, malondialdehyde, vitamin C, and glutathione peroxidase-1. RESULTS: Twenty-two patients were enrolled, of which 18 concluded the trial, 6 per group (18.2%, n = 4 losses during follow-up). The vitamin C group presented decreased GSH levels after supplementation (p = 0.053) and a decreasing tendency in the GSH:GSSG ratio (non-statistically significant), while MDA levels significantly decreased only in the whey protein-supplemented groups (p ≤ 0.05). CONCLUSION: The results suggest a pro-oxidant effect of 0.25 g of vitamin C alone in chronic HD patients. CLINICAL TRIAL REGISTRATION: https://ensaiosclinicos.gov.br/ , RBR-65b8f4.
Authors: Hadi Abdollahzad; Shahriar Eghtesadi; Issa Nourmohammadi; Mohammadhasan Khadem-Ansari; Hossein Nejad-Gashti; Ahmad Esmaillzadeh Journal: Int J Vitam Nutr Res Date: 2009-09 Impact factor: 1.784
Authors: Zahra Sohrabi; Mohammad Hassan Eftekhari; Mohammad Hadi Eskandari; Abbas Rezaianzadeh; Mohammad Mahdi Sagheb Journal: Am J Kidney Dis Date: 2016-04-15 Impact factor: 8.860
Authors: Aimee N Winter; Erika K Ross; Vamsi Daliparthi; Whitney A Sumner; Danielle M Kirchhof; Evan Manning; Heather M Wilkins; Daniel A Linseman Journal: Oxid Med Cell Longev Date: 2017-08-15 Impact factor: 6.543