Brazil nut ingestion increased plasma selenium but had minimal effects on lipids, apolipoproteins, and high-density lipoprotein function in human subjects

The Brazil nut (Bertholletia excelsa) of the Amazon region is consumed worldwide. It is rich in both monounsaturated fatty acids and polyunsaturated fatty acids and is known for its high selenium content. This study tested the hypothesis whether the consumption of this nut could affect the plasma lipids and apolipoproteins and some functional properties of the antiatherogenic high-density lipoprotein (HDL). Fifteen normolipidemic subjects aged 27.3 +/- 3.9 years and with body mass index of 23.8 +/- 2.8 kg/m(2) consumed 45 g of Brazil nuts per day during a 15-day period. On days 0 and 15, blood was collected for biochemical analysis, determination of HDL particle size, paraoxonase 1 activity, and lipid transfer from a lipoprotein-like nanoparticle to the HDL fraction. Brazil nut ingestion did not alter HDL, low-density lipoprotein cholesterol, triacylglycerols, apolipoprotein A-1, or apolipoprotein B concentrations. HDL particle diameter and the activity of antioxidative paraoxonase 1, mostly found in the HDL fraction, Were also unaffected. Supplementation increased the reception of cholesteryl esters (P <.05) by the HDL yet did not alter the reception of phospholipids, free cholesterol, or triacylglycerols. As expected, plasma selenium was significantly increased. However, the consumption of Brazil nuts for short duration by normolipidemic subjects in comparable amounts to those tested for other nuts did not alter serum lipid profile. The only alteration in HDL function was the increase in cholesteryl ester transfer. This latter finding may be beneficial because it would improve the nonatherogenic reverse cholesterol transport pathway. (c) 2008 Elsevier Inc. All rights reserved.

Effect of Brazil nut supplementation on the blood levels of selenium and glutathione peroxidase in hemodialysis patients

Objective: In patients who have undergone hemodialysis, large amounts of reactive oxygen species (ROS) are produced and, at higher concentrations, ROS are thought to be involved in the pathogenesis of cardiovascular disease. It has been proposed that selenium (Se) may exert an anti-atherogenic influence by reducing oxidative stress. The richest known food source of selenium is the Brazil nut (Bertholletia excelsa, family Lecythidaceae), found in the Amazon region. We evaluated the effect of Brazil nut supplementation on blood levels of Se and glutathione peroxidase (GSH-Px) activity in patients on hemodialysis. Methods: A total of 81 patients on hemodialysis (52.0 +/- 15.2 y old, average time on dialysis 82.3 +/- 91.4 mo, body mass index 24.9 +/- 4.4 kg/m(2)) from the RenalCor and RenalVida Clinics in Rio de Janeiro, Brazil, were studied. All patients received one nut (around 5 g, averaging 58.1 mu g Se/g) a day for 3 mo. The Se concentrations in the nuts and in plasma and erythrocytes were determined by atomic absorption spectrophotometry with hydride generation (Hitachi, Z-500). GSH-Px levels were measured using Randox commercial kits. Results: Plasma Se (18.8 +/- 17.4 mu g/L) and erythrocyte (72.4 +/- 37.9 mg/L) levels were below the normal, range before nut supplementation. After supplementation, the plasma level increased to 104.0 +/- 65.0 mu g/L and erythrocytes to 244.1 +/- 119.5 mg/L (P<0.0001). The activity of GSH-Px also increased after supplementation, from 46.6 +/- 14.9 to 55.9 +/- 23.6 U/g of hemoglobin (P<0.0001). Before supplementation, 11% of patients had GSH-Px activity below the normal range (27.5-73.6 U/g of hemoglobin). After supplementation, all patients showed GSH-Px activity within the normal range. Conclusion: The data revealed that the investigated patients presented Se deficiency and that the consumption of only one Brazil nut a day (5 g) during 3 mo was effective to increase the Se concentration and GSH-Px activity in these patients, thus improving their antioxidant status. (C) 2010 Elsevier Inc. All rights reserved.

Nutritional status of selenium in Alzheimer`s disease patients

Studies have shown that various antioxidants are decreased in different age-related degenerative diseases and thus, oxidative stress would have a central role in the pathogenesis of many disorders that involve neuronal degeneration, including Alzheimer`s disease (AD). The present study aimed to assess the nutritional status of Se in AD patients and to compare with control subjects with normal cognitive function. The case control study was carried out on a group of elderly with AD (n 28) and compared with a control group (n 29), both aged between 60 and 89 years. Se intake was evaluated by using a 3-d dietary food record. Se was evaluated in plasma, erythrocytes and nails by using the method of hydride generation atomic absorption spectroscopy. Deficient Se intake was largely observed in the AD group. AD patients showed significantly lower Se levels in plasma, erythrocytes and nails (32.59 mu g/l, 43.74 mu g/l and 0.302 mu g/g) when compared with the control group (50.99 mu g/l, 79.16 mu g/l and 0.400 mu g/g). The results allowed us to suggest that AD has an important relation with Se deficiency.

Deficient selenium status of a healthy adult Spanish population.

INTRODUCTION Selenium is an essential micronutrient for human health, being a cofactor for enzymes with antioxidant activity that protect the organism from oxidative damage. An inadequate intake of this mineral has been associated with the onset and progression of chronic diseases such as hypertension, diabetes, coronary diseases, asthma, and cancer. For this reason, knowledge of the plasma and erythrocyte selenium levels of a population makes a relevant contribution to assessment of its nutritional status. OBJECTIVE The objective of the present study was to determine the nutritional status of selenium and risk of selenium deficiency in a healthy adult population in Spain by examining food and nutrient intake and analyzing biochemical parameters related to selenium metabolism, including plasma and erythrocyte levels and selenium-dependent glutathione peroxidase (GPx) enzymatic activity. MATERIAL AND METHODS We studied 84 healthy adults (31 males and 53 females) from the province of Granada, determining their plasma and erythrocyte selenium concentrations and the association of these levels with the enzymatic activity of glutathione peroxidase (GPx) and with life style factors. We also gathered data on their food and nutrient intake and the results of biochemical analyses. Correlations were studied among all of these variables. RESULTS The mean plasma selenium concentration was 76.6 ± 17.3 μg/L (87.3 ± 17.4 μg/L in males, 67.3 ± 10.7 μg/L in females), whereas the mean erythrocyte selenium concentration was 104.6 μg/L (107.9 ± 26.1 μg/L in males and 101.7 ± 21.7 μg/L in females). The nutritional status of selenium was defined by the plasma concentration required to reach maximum GPx activity, establishing 90 μg/L as reference value. According to this criterion, 50% of the men and 53% of the women were selenium deficient. CONCLUSIONS Selenium is subjected to multiple regulation mechanisms. Erythrocyte selenium is a good marker of longer term selenium status, while plasma selenium appears to be a marker of short-term nutritional status. The present findings indicate a positive correlation between plasma selenium concentration and the practice of physical activity. Bioavailability studies are required to establish appropriate reference levels of this mineral for the Spanish population.

Selenium and vitamin A and E in the nutrition of very low-birth weight preterm infants

Deficient antioxidant defenses in preterm infants have been implicated in diseases such as bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, periventricular leukomalacia, and intraventricular hemorrhage. The antioxidant properties of selenium, vitamin A, and vitamin E make these elements important in the nutrition of Very Low-Birth Weight (VLBW) infants. Selenium is a component of glutathione peroxidase, an enzyme that prevents the production of free radicals. The decrease in plasma selenium in VLBW infants in the first month after birth makes evident that preterm infants have low selenium store and require supplementation by parenteral and enteral nutrition. A meta-analysis, with only three trials, showed that selenium supplementation did not affect mortality, and the incidence of neonatal chronic lung disease or retinopathy of prematurity, but was associated with a reduction in lateonset sepsis. Most VLBW infants and extremely Low-Birth Weight Infants (ELBW) are born with low vitamin A stores and need vitamin A supplementation by intramuscular or enteral route. Low plasma retinol concentrations increase the risk of chronic lung disease/bronchopulmonary dysplasia and long-term respiratory disabilities in preterm infants. There is evidence that vitamin A supplementation decreases the mortality or oxygen requirement at one month of age, and oxygen requirement at 36 weeks’ postmenstrual age. Vitamin E blocks natural peroxidation of polyunsaturated fatty acids from lipid layers of cell membranes. VLBW infants have a decrease in plasma concentrations in the first month after birth suggesting the need of vitamin E supplementation. A meta-analysis on vitamin E supplementation concluded that vitamin E did not affect mortality, risk of bronchopulmonary dysplasia, and necrotizing enterocolitis but reduced the risk of intraventricular hemorrhage and increased the risk of sepsis. Serum vitamin E concentrations higher than 3.5 mg/dL are associated with a decrease in the risk of severe retinopathy of prematurity, and blindness, but also with an increase in neonatal sepsis. Caution is recommended with the supplementation of high doses of parenteral vitamin E and supplementation that increases serum levels above 3.5 mg/dL. In conclusion: although it is known that preterm infants are deficient in selenium, vitamin A and E, more studies are required to determine the best way to supplement and the impact of supplementation on neonatal outcome.

Trace element supplementation modulates pulmonary infection rates after major burns: a double-blind, placebo-controlled trial.

Infections remain the leading cause of death after major burns. Trace elements are involved in immunity and burn patients suffer acute trace element depletion after injury. In a previous nonrandomized study, trace element supplementation was associated with increased leukocyte counts and shortened hospital stays. This randomized, placebo-controlled trial studied clinical and immune effects of trace element supplements. Twenty patients, aged 40 +/- 16 y (mean +/- SD), burned on 48 +/- 17% of their body surfaces, were studied for 30 d after injury. They consumed either standard trace element intakes plus supplements (40.4 micromol Cu, 2.9 micromol Se, and 406 micromol Zn; group TE) or standard trace element intakes plus placebo (20 micromol Cu, 0.4 micromol Se, and 100 micromol Zn; group C) for 8 d. Demographic data were similar for both groups. Mean plasma copper and zinc concentrations were below normal until days 20 and 15, respectively (NS). Plasma selenium remained normal for group TE but decreased for group C (P < 0.05 on days 1 and 5). Total leukocyte counts tended to be higher in group TE because of higher neutrophil counts. Proliferation to mitogens was depressed compared with healthy control subjects (NS). The number of infections per patient was significantly (P < 0.05) lower in group TE (1.9 +/- 0.9) than in group C (3.1 +/- 1.1) because of fewer pulmonary infections. Early trace element supplementation appears beneficial after major burns; it was associated with a significant decrease in the number of bronchopneumonia infections and with a shorter hospital stay when data were normalized for burn size.

Associação entre a concentração de selênio, o polimorfismo Pro198Leu da glutationa peroxidase 1 e a mortalidade em pacientes com choque séptico

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Influência da infecção pelo HIV e do uso da terapia antirretroviral nas concentrações de selênio, selenometionina e proteção antioxidante

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influência da infecção pelo HIV e do uso da terapia antirretroviral nas concentrações de selênio, selenometionina e proteção antioxidante

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of different genotypes in the pattern of selenoprotein expression in response to Brazil nut supplementation

The micronutrient selenium is essential to human physiology. As the amino acid selenocysteine, it is inserted into selenoproteins with a wide range of functions including antioxidant capacity, thyroid hormone metabolism, improvement of immune system, brain function, fertility and reproduction. Low selenium status has been associated with increased risk for chronic diseases, such as cancer, type-2 diabetes and cardiovascular disease. In this context, several studies have been conducted in order to investigate if selenium supplementation could reduce the risk of such diseases. However, genetic variations may interfere in the response of individuals to a dietary intervention and must be considered as a important source of inter-individual variation. Therefore, this study was conducted was conducted to investigate the influence of genetic variations in selenoproteins genes on the response to an intervention with Brazil nuts, the richest source of selenium known in nature. The study included 130 healthy volunteers with both genders, aged 20 to 60 years old selected in University of São Paulo. They received nuts for 8 weeks, eating one nut a day, and did a washout period for more 8 weeks. All volunteers had a blood sampling collection every 4 weeks during 4 months, in a total of 5. The following analysis were done: anthropometric measurements, lipid profile, plasma malondialdehyde, plasma and erythrocyte Se, selenoprotein P, plasma and erythrocyte GPx activity, gene expression of GPX1, SEPP1, SELS and SEP15. The volunteers were also genotyped for SNPs rs1050450, rs3811699, rs1800699, rs713041, rs3877899, rs7579, rs34713741 and rs5845. Each unit of Brazil nut provided an average of 300 µg of selenium. All 130 volunteers completed the protocol. The concentrations of total cholesterol and glucose decreased after 8 weeks of supplementation. Moreover, HDL concentrations were higher for carriers of the variant T allele for GPX4_rs713041. The frequencies of the variant genotypes were 5,4% for rs1050450, rs3811699 e rs1088668, 10% for rs3877899, 19,2% for rs713041 e rs7579, 11,5% for rs5845 and 8,5% for rs34713741. The levels of the five biomarkers increased significantly after supplementation. In addition, erythrocyte GPx activity was influenced by rs1050450, rs713041 and rs5845; erythrocyte selenium was influenced by rs5845 and plasma selenium by rs3877899. Gene expression of GPX1, SEPP1 and SEP15 were higher after supplementation. The SNP rs1050450 influenced GPX1 mRNA expression and rs7579 influenced SEPP1 mRNA expression. Therefore, it can be concluded that the supplementation with one of Brazil nut for 8 weeks was efficient to reduce total cholesterol and glucose levels and to increase the concentrations of the main biomarkers of selenium status in healthy adults. Furthermore, our results suggest that GPX4_rs713041 might interfere on HDL concentrations and GPx1 activity, GPX1_rs1050450 might interfere on GPx1 activity, SEP15_rs5845 might interfere on GPx1 activity and erythrocyte selenium and SEPP1_3877899 might interfere on plasma Se levels. Therefore, the effect of genetic variations should be considered in future nutritional interventions evaluating the response to Brazil nut supplementation.

Selenium plasma levels in hemodialysis patients: Comparison between North and Southeast of Brazil

Introduction: Patients with chronic kidney disease present selenium (Se) plasma deficiency which is an essential trace element with important biological functions and, the best known biological role is attributed to its presence in the antioxidant enzyme, glutathione peroxidase (GPx). The Se content of foods depends on soil and some authors have suggested that Amazon soil (North Brazilian region) has high Se concentrations when compared to other regions of Brazil. Objective: The objective of this work was to compare the Se status in hemodialysis (HD) patients from North and Southeast of Brazil. Methods: Thirty-eight patients from Southeast region (22 men and 16 women, 15% diabetic, 53.5 ± 26.4 yrs) were compared to 40 patients from North region (28 men and 12 women, 22.5% diabetic, 63.5 ± 11.9 yrs). Se in plasma was determined through atomic absorption spectrophotometry with hydride generation. Results: The plasma Se levels in patients from Southeast region were significantly lower (17.5 ± 11.9 μg/L) when compared to patients from the North (37.1 ± 15.8 μg/L) (p < 0.001). However, both patient groups presented low Se plasma levels when compared to recommended values (60- 120 μg/L). There was no correlation between plasma Se levels and analyzed parameters. Conclusion: We concluded that patients from North (Amazon) region present higher plasma Se levels when compared to the patients from Southeast of Brazil. However, independently of the region, HD patients presented Se deficiency.

Selenium fractionation from plasma, muscle and liver of Nile tilapia (Oreochromis niloticus)

This paper presents the results obtained from selenium fractionation in plasma, muscle and liver samples of Nile tilapia's (Oreochromis niloticus) after protein separation. The plasma, muscle and liver proteome was obtained by 2D-PAGE, and selenium in protein spots was qualitatively and quantitatively determined by synchrotron radiation X-ray fluorescence and graphite furnace atomic absorption spectrometry (GFAAS). The fluorescence spectra indicated the presence of selenium in three protein spots of plasma, two of muscle and one of liver. Selenium was found to be distributed mainly in proteins with a molar mass smaller than 57.0 kDa and with pI in the range of 5.9-9.6, with one exception in the plasma sample, which presented protein with a molar mass of 60.0 kDa. After acid mineralization of the protein spots, a GFAAS determination of the concentration of selenium bound to these proteins indicated a range of 1.35-6.82 mg per g of protein. © 2013 Springer Science+Business Media New York.

Blood and seminal plasma concentrations of selenium, zinc and testosterone and their relationship to sperm quality and testicular biometry in domestic cats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of Brazil Nut Supplementation on Plasma Levels of Selenium in Hemodialysis Patients: 12 Months of Follow-up

Background: Large amounts of reactive oxygen species are produced in hemodialysis (HD) patients, and, at higher concentrations, reactive oxygen species are thought to be involved in the pathogenesis of cardiovascular disease. It has been proposed that selenium (Se) may exert an antiatherogenic influence by reducing oxidative stress. The richest known food source of Se is the Brazil nut (Bertholletia excelsa, family Lecythidaceae), found in the Amazon region. Objective: The objective of this work was to determine if Se plasma levels in HD patients submitted to a program of supplementation during 3 months with 1 Brazil nut by day could be sustained after 12 months. Methods: A total of 21 HD patients (54.2 +/- 15.2 years old; average time on dialysis, 82.3 +/- 51.6 months; body mass index, 24.4 +/- 3.8 kg/m(2)) from the RenalCor Clinic in Rio de Janeiro, Brazil, were followed up 12 months after the supplementation study ended. The Se plasma levels were determined by atomic absorption spectrophotometry with hydride generation. Results: The Se Plasma levels (17.3 +/- 19.9 mg/L) were below the normal range (60 to 120 mu g/L) before nut supplementation, and after 3 months of supplementation, the levels increased to 106.8 +/- 50.3 mu g/L (P < .0001). Twelve months after supplementation, the plasma Se levels decreased to 31.9 +/- 14.8 mu g/L (P < .0001). Conclusions: The data showed that these patients were Se deficient and that the consumption of Brazil nut was effective to increase the Se parameters of nutritional status. Se levels 12 months after the supplementation period were not as low as presupplementation levels but yet significantly lower, and we needed to motivate patients to adopt different dietary intake patterns. (C) 2012 by the National Kidney Foundation, Inc. All rights reserved.