Biological trace element research

A follow-up study of the chronic kidney disease patients treated with Brazil nut: focus on inflammation and oxidative stress.

PMID 25395121


Brazil nut is the richest known food source of selenium. The supplementation with Brazil nut during 3xa0months 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 3xa0months for the HD patients could be sustained after 12xa0months. Twenty-nine HD patients (58.6xa0% men, 51.0 ± 3.3xa0years) from RenalCor Clinic, Rio de Janeiro, Brazil, were followed up 12xa0months 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 3xa0months of supplementation and after 12xa0months. 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 12xa0months, 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 12xa0months increased compared to the basal levels. Consequently, it is necessary to motivate patients to adopt different dietary intake patterns.