Table 2.
Non-randomized clinical trials evaluating the effects of Brazil nut consumption on human health (n = 15).
| Reference | Sample Characteristics | Intervention Characteristics | Study Design and Duration | Evaluated Markers | Results |
|---|---|---|---|---|---|
| Controlled clinical trials | |||||
| [23] Brazil |
n: 25 subjects on hemodialysis G1 (n = 13): Age: 57.1 (SD 12) y BMI: 24.4 (SD 3.2) kg/m2 G2 (n = 12): Age: 52 (SD 15.5) y BMI: 26.1 (SD 5.8) kg/m2 |
G1: one unit/day of BN (~5 g with 290.5 µg of Se) G2: control |
Controlled clinical trial 12 weeks |
Antioxidant status Inflammation Oxidative stress |
G1: ↑ mRNA expression of Nrf2, NAD(P)H: quinone oxidoreductase 1 (NQO1) and ↓ mRNA expression of NF-κB vs. G2 G1: ↓ MDA, IL-6 vs. baseline |
| Uncontrolled clinical trial | |||||
| [24] Brazil |
n: 15 normolipidemic subjects Age: 27.3 (SD 3.9) y BMI: 23.8 (SD 2.8) kg/m2 |
45 g/day of BN (11 units with 862.65 µg of Se) | Clinical trial 15 days |
Antioxidant status Anthropometry Lipid metabolism markers |
↑ Se in plasma and reception of cholesteryl esters by HDL-c ↔ weight, total cholesterol, LDL-c, HDL-c, TG, Apo A-I, Apo B, HDL-c diameter, PON 1 activity, % cholesterol, TG, and phospholipid transfer |
| [25] Brazil |
n: 81 hemodialysis patients Age: 52 (SD 15.2) y BMI: 24.9 (SD 4.4) kg/m2 |
One unit/day of BN (~5 g with 290.5 µg Se) | Clinical trial 12 weeks |
Antioxidant status | ↑ Se in plasma and erythrocytes ↑ GSH-Px activity in erythrocytes (began to be within normal) |
| [26] Brazil |
n: 37 morbidly obese women Age: 34.5 (SD 6.8) y BMI: 45.2 (SD 4.2) kg/m2 |
One unit/day of BN (~290 µg of Se) | Clinical trial 8 weeks |
Antioxidant status Glucose Anthropometry DNA damage |
↑ Se in plasma and erythrocytes and GPx activity in all genotypes ↓ DNA damage in those with the Pro/Pro genotype. vs. baseline ↑ DNA damage in those with genotype Leu/Leu vs. Pro/Read ↔ weight, BMI, blood glucose |
| [27] Brazil |
n: 37 morbidly obese women Age: 34.5 (SD 6.8) y BMI: 45.2 (SD 4.2) kg/m2 |
One unit/day of BN (~290 µg of Se) | Clinical trial 8 weeks |
Antioxidant status Lipid profile markers Glucose Anthropometry |
↑ Se in plasma and erythrocytes ↑ GPx activity ↑ HDL-c ↓ TC/HDL-c and LDL-c/HDL-c ratio ↔ weight, BMI, total cholesterol, LDL-c, VLDL-c, TC, fasting glucose |
| [28] Brazil |
n: 21 hemodialysis patients Age: 54.2 (SD 15.2) y BMI: 24.4 (SD 3.8) kg/m2 |
One unit/day of BN (~5 g with 290.5 µg Se) | Clinical trial 12 weeks |
Antioxidant status Anthropometry, body fat, Kidney function markers Minerals |
↑ Se in plasma ↓ urea nitrogen Follow-up after 12 months: ↓ Se in plasma and urea nitrogen ↔ BMI, body fat, WC, creatinine, minerals |
| [29] Brazil |
n: 40 hemodialysis patients Age: 53.3 (SD 16.1) y |
One unit/day of BN (~5 g with 290.5 µg Se) | Clinical trial 12 weeks |
Antioxidant status Lipid metabolism markers Inflammation Oxidative stress and DNA damage |
↑ Se, GPx activity and HDL-c in plasma ↓ TNF, IL-6, 8-OHdG, 8-isoprostane, LDL-c, Castelli index I and II ↔ total cholesterol, TG |
| [30] Brazil |
n: 29 hemodialysis patients Age: 51 (SD 3.3) y BMI: 23.6 (17.7–40.3) kg/m2 |
One unit/day of BN (~5 g with 290.5 µg Se) | 12-month follow-up after 3 months of BN consumption | Antioxidant status Lipid metabolism markers Inflammation Oxidative stress and DNA damage |
↓ Se and GPx activity in plasma ↑ TNF, IL-6, 8-OHdG, 8-isoprostane ↔ total cholesterol, TG, LDL-c, HDL-c |
| [31] Brazil |
n: 40 hemodialysis patients Age: 53.3 (SD 16.1) y |
One unit/day of BN (~5 g with 290.5 µg Se) | Clinical trial 12 weeks |
Antioxidant status Thyroid function markers |
↑ Se in plasma, GPx activity, T3 and T4 levels ↔ TSH |
| [32] Brazil |
n: 130 healthy subjects Age: 29.8 (SD 9.2) y BMI: 23.3 (SD 3.3) kg/m2 |
One unit/day of BN (3 to 4 g with ~300 µg of Se) | Clinical trial 8 weeks |
Glucose and lipid metabolism markers | ↓ glucose at 4 and 8 weeks and total cholesterol at 8 weeks |
| [33] Brazil |
n: 130 healthy subjects Age: 29.8 (SD 9.2) y BMI: 23.3 (SD 3.3) kg/m2 |
One unit/day of BN (3 to 4 g with ~300 µg of Se) | Clinical trial 8 weeks |
Antioxidant status | ↑ mRNA expression of GPX1 in subjects with genotype in rs713041 ↑ Selenoprotein P mRNA expression in A allele carriers in rs7579 before and after consumption |
| [34] Brazil |
n: 130 healthy subjects Age: 29.8 (SD 9.2) y BMI: 23.3 (SD 3.3) kg/m2 |
One unit/day of BN (3 to 4 g with ~300 µg of Se) | Clinical trial 8 weeks |
Antioxidant status | GPx1 activity: ↓ at 4 weeks but did not differ from baseline at 8 weeks GPx3 activity: ↑ at 4 weeks but did not differ from baseline at 8 weeks Se in plasma and erythrocytes: ↑ at 4 and 8 weeks Selenoprotein P: ↑ in 8 weeks |
| [35] Brazil |
n: 60 subjects with type 2 diabetes Men: Age: 62 (SD 9) y BMI: 30.2 (SD 3.2) Women: Age: 66 (SD 8) BMI: 32.6 (SD 4.1) |
One unit of BN/day (~3.7 g with 213.67 µg of Se) | Clinical trial 24 weeks |
Antioxidant status Anthropometry DNA damage Glucose metabolism markers |
↑ Se, waist circumference, glycemia ↓ DNA damage, both basal and cell-induced oxidative damage ↔ BMI, HbA1c |
| [36] Brazil |
n: 32 patients using statins | G1: one unit/day of BN (~5 g with 290 µg of Se) for subjects classified as having high concentrations of creatine kinase G1: one unit/day of BN (~5 g with 290 µg of Se) for subjects classified as having normal creatine kinase concentration |
Clinical trial 12 weeks |
Antioxidant status Oxidative stress Lipid metabolism marker |
G1, G2: ↓ concentrations of protein kinase, MDA, SOD vs. baseline G1, G2: ↑ Se in plasma and erythrocytes, GPx vs. baseline ↔ total cholesterol and mRNA expression of selenoproteins |
| [37] Brazil |
n: 32 patients using statins Age: 50.1 (SEM 7.6) y BMI: 31.1 (SEM 3.8) kg/m2 |
One unit/day of BN (~5 g with 290 µg of Se) | Clinical trial 12 weeks |
Antioxidant status Anthropometry Oxidative stress Lipid metabolism marker |
↑ erythrocyte GPx activity in all genotypes for the rs1050450 polymorphism in the GPx ↑ erythrocyte GPx activity for those with CC genotype for the rs3877899 polymorphism in the SELENOP and all genotypes for rs7579 polymorphism in the SELENOP ↓ creatine kinase in all genotypes for the rs1050450 polymorphism in the GPx ↓ creatine kinase for those with CC genotype for the rs3877899 polymorphism in the SELENOP and GG genotype for rs7579 polymorphism in the SELENOP |
Legend: ↑, increased; ↓, decreased; ↔ unchanged; G, group; SD, standard deviation; BN, Brazil nut; Se, selenium; BMI, body mass index; Nrf2, nuclear factor erythroid 2-related factor 2; NQO1, NAD(P)H: quinone oxidoreductase 1; NF-κB, nuclear factor kappa B; MDA, malondialdehyde; IL-6, interleukin 6; HDL-c, high-density lipoprotein cholesterol; LDL-c, low-density lipoprotein cholesterol; TG, triglycerides; VLDL-c, very-low-density lipoprotein cholesterol; PON 1, paraoxonase 1; Apo-A1, apolipoprotein A-1; Apo B, apolipoprotein B; GSH-Px, glutathione peroxidase; GPx, glutathione peroxidase; TNF, tumor necrosis factor; T3, triiodothyronine; T4, thyroxine; TSH, thyroid-stimulating hormone; DNA, deoxyribonucleic acid; HbA1c, glycated hemoglobin; SOD, superoxide dismutase; 8-OHdG, 8-hydroxydeoxyguanosine; SELENOP, selenoprotein P.