A Follow-up Study of the Chronic Kidney Disease Patients Treated with Brazil Nut: Focus on Inflammation and Oxidative Stress

Abstract

Brazil nut is the richest known food source of selenium. The supplementation with Brazil nut during 3months was effective in reducing oxidative stress and inflammation in hemodialysis (HD) patients. However, there are no available data on the antioxidant effect after that supplementation. The objective of this work was to determine if the beneficial effects of one Brazil nut supplementation per day during 3months for the HD patients could be sustained after 12months. Twenty-nine HD patients (58.6% men, 51.0 ± 3.3years) from RenalCor Clinic, Rio de Janeiro, Brazil, were followed up 12months after the supplementation study had finished. The plasma levels of antioxidant substances as selenium, glutathione peroxidase (GPx), 8-isoprostane, 8-hydroxy-2-deoxyguanosine (8-OHdG) and cytokines (tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6)) were determined before, after 3months of supplementation and after 12months. After 3-months supplementation, cytokines, 8-OHdG and 8-isoprostane plasma levels have decreased and the activity of GPx and selenium plasma levels have increased significantly. Additionally, after 12months, the values of 8-isoprostane, 8-OHdG and cytokines increased and the activity of GPx and selenium plasma levels decreased significantly. The levels of oxidative stress and inflammation biomarkers after 12months increased compared to the basal levels. Consequently, it is necessary to motivate patients to adopt different dietary intake patterns.