ObjectivesTo investigate the effect of partially defatted Granulated Brazil nut (GBN) on biomarkers of oxidative stress and antioxidant status of hypertensive and dyslipidemic patients on nutrition and drug approaches.MethodsNinety one hypertensive and dyslipidemic subjects of both genders (51.6 % men), mean age 62.1 ± 9.3 years, performed a randomized crossover trial, double-blind, placebo controlled. Subjects received a diet and partially defatted GBN 13 g per day (≈227.5 μg/day of selenium) or placebo for twelve weeks with four-week washout interval. Anthropometric, laboratory and clinic characteristics were investigated at baseline. Plasma selenium (Se), plasma glutathione peroxidase (GPx3) activity, total antioxidant capacity (TAC), 8-epi PGF2α and oxidized LDL were evaluated at the beginning and in the end of each intervention.ResultsGBN intake significantly increased plasma Se from 87.0 ± 16.8 to 180.6 ± 67.1 μg/L, increased GPx3 activity in 24,8 % (from 112.66 ± 40.09 to 128.32 ± 38.31 nmol/min/mL, p < 0,05), and reduced 3.25 % of oxidized-LDL levels (from 66.31 ± 23.59 to 60.68 ± 20.88 U/L, p < 0.05). An inverse association between GPx3 and oxidized LDL levels was observed after supplementation with GBN by simple model (β -0.232, p = 0.032) and after adjustment for gender, age, diabetes and BMI (β -0.298, p = 0.008). There wasn’t association between GPx3 and 8-epi PGF2α (β -0.209, p = 0.052) by simple model.ConclusionThe partially defatted GBN intake has a potential benefit to increase plasma selenium, increase enzymatic antioxidant activity of GPx3 and to reduction oxidation in LDL in hypertensive and dyslipidemic patients.Trial registrationClinicalTrials.gov Identifier NCT01990391; November 20, 2013.