Improvement of antioxidant status after Brazil nut intake in hypertensive and dyslipidemic subjects

Adults with hypertension and dyslipidemia (>20 years; mean age 62.1 ± 9.3 years; 51.6% male). 125 randomized; 91 completed. Randomized, double-blind, placebo-controlled crossover trial.

Partially defatted Granulated Brazil nut; 13 g/day for 12 weeks; consumed as a standard daily measure providing ≈227.5 μg selenium.

Brazil nut intake increased plasma selenium from 87.0 ± 16.8 to 180.6 ± 67.1 μg/L and boosted GPx3 activity by 24.8% (112.66 ± 40.09 to 128.32 ± 38.31 nmol/min/mL; p<0.05). Oxidized-LDL decreased from 66.31 ± 23.59 to 60.68 ± 20.88 U/L (p<0.05). An inverse association between GPx3 activity and oxidized-LDL emerged after Brazil nut intake (p=0.032; adjusted p=0.008). 8-epi PGF2α showed no association with GPx3 in simple model (p=0.052); after adjustment, significant inverse relation appeared (p=0.034). Total antioxidant capacity was higher with the Brazil nut diet than placebo at 12 weeks (p=0.024). Conclusion: Partially defatted Granulated Brazil nut (13 g/day) may elevate selenium status, enhance GPx3 activity, and reduce LDL oxidation in hypertensive and dyslipidemic patients; including Brazil nuts may support heart-healthy antioxidant defenses.

Carryover effect in selenium levels after washout; 27.2% dropout; relatively short 12-week duration; participant heterogeneity; potential residual confounding due to crossover.