Effects of a Brazil nut‐enriched diet on oxidative stress and inflammation markers in coronary artery disease patients: A small and preliminary randomised clinical trial

Abstract

Nutritional interventions can reduce complications associated with coronary artery disease (CAD) such as inflammation and oxidative stress. This small, preliminary study aimed to evaluate a Brazil nut‐enriched diet's effects on markers of oxidative stress and inflammation in CAD patients. Twenty‐five CAD patients (13 male, 63.3 ± 6.7 years, BMI of 29.3 ± 5.6 kg/m2) were randomised to receive one unit of Brazil nut (5 g) per day for 3 months and were compared to 17 CAD patients (8 male, 63.3 ± 8 years, BMI of 28.6 ± 4.8 kg/m2) who served as control. Peripheral blood mononuclear cells were isolated, processed and analysed for expression of the transcription factors nuclear factor kappa B (NF‐κB) and nuclear factor E2‐related factor 2 (Nrf2), which is involved with antioxidant synthesis, and the antioxidant enzyme NAD(P)H: quinone oxidoreductase 1 (NQO1) by quantitative real‐time polymerase chain reaction (PCR). Plasma thiobarbituric acid‐reactive substances (TBARS) and clinical parameters were also measured before and after supplementation. No significant differences were found in any of the analysed parameters. Supplementing the diet with one Brazil nut a day for 3 months did not mitigate inflammation and oxidative stress in CAD patients. A longer period of supplementation may be required for positive effects to be seen.

Effects of Regular Brazil Nut (Bertholletia excelsa H.B.K.) Consumption on Health: A Systematic Review of Clinical Trials

“…Approximately 93% of the publications were from research conducted in Brazil between 2008 and 2022. Thirteen [ 17 , 19 , 20 , 21 , 22 , 26 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ] of the twenty-four studies included in this systematic review are new compared to the review carried out by Cardoso et al (2017).…”

“…Of the twenty-four, nine publications were the results of randomized clinical trials. Of these, two studies were placebo-controlled [ 14 , 15 ], seven were controlled [ 16 , 17 , 18 , 19 , 20 , 21 , 22 ], and sixteen were non-randomized clinical trials. Only two non-randomized studies were controlled [ 23 ], whereas all others were uncontrolled [ 14 , 15 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ].…”

“…Regular (15 days to 12 weeks) consumption of BNs (1–11 units/day; 48 µg to 862.65 µg of Se) improved the antioxidant statuses (increased Se in plasma and erythrocytes, GPx, GPx3, SELENOP, and SELENOP mRNA expression), and lipid profiles (decreased TC and increased HDL-c cholesteryl reception) of healthy subjects and reduced their fasting glucose [ 16 , 17 , 21 , 30 , 32 , 38 ] ( Figure 3 ). Similarly, acute consumption of 1–10 units/day of BNs (156 µg to 1560 µg of Se) associated with a normocaloric diet improved the antioxidant statuses (increased Se in plasma) and lipid profiles (increased HDL-c, decreased LDL-c, and atherogenic indices) in 24 postprandial hours up to 30 days after a single day of consumption [ 38 , 39 ].…”

“…No significant changes in Nrf2, NF-κB, NQO1, or peroxisome proliferator-activated receptor (PPARβ/δ) mRNA expression levels or markers of lipid metabolism and inflammation were found in subjects with coronary artery disease after three months of intervention with one unit/day of BNs (~290.5 µg of Se) compared to the control group. Controversial results regarding changes in TBARS were observed in the two articles on the effect of BN consumption in individuals with coronary artery disease [ 21 , 22 ] ( Figure 3 ). The authors did not provide the baseline values of plasma Se values.…”

Brazil nut supplementation does not affect trimethylamine‐n‐oxide plasma levels in patients with coronary artery disease

“…Briefly, convenience sampling is considered a non-probability sampling method characterized by recruiting conveniently available subjects for the study who meet the inclusion criteria. This study is a secondary analysis of a pilot randomized 1 × 1 factorial design trial examining the effects of Brazil nuts supplementation on nuclear factor erythroid 2-related factor 2 (Nrf2) expression in CAD patients, from June 2015 to November 2015 (Cardozo et al, 2021). The sample calculation was made considering a test power of 80%, Type-I error probability with the null hypothesis of 0.05.…”