Brazilian nut consumption improves selenium status and glutathione peroxidase activity and reduces atherogenic risk in obese women

Brazil nut consumption reduces DNA damage in overweight type 2 diabetes mellitus patients

Type 2 diabetes mellitus (T2D) is a metabolic disease, which occurs largely due to unhealthy lifestyle. As oxidative stress is believed to promote T2D, by inducing damage to lipids, proteins, and DNA, appropriate dietary interventions seem critical to prevent, manage, and even reverse this condition. Brazil nuts (Bertholletia excelsa, H.B.K.) are nature's richest source of selenium, a mineral that has shown several health benefits. Therefore, this study aims to assess the effects of selenium consumption, through Brazil nuts, on biochemical and oxidative stress parameters, and genomic instability in T2D patients. We recruited 133 patients with T2D, registered in the Integrated Clinics of the University of Southern Santa Catarina (Brazil). Participants consumed one Brazil nut a day for six months. Blood samples and exfoliated buccal cells were collected at the beginning and the end of the intervention. The glycemic profile, lipid profile, renal profile and hepatic profile, DNA damage and selenium content were evaluated. A total of 74 participants completed the intervention. Brazil nut consumption increased selenium and GSH levels, GPx, and CAT activity while DCF and nitrites levels decreased. Total thiols increased, and protein carbonyl and MDA levels decreased. Levels of baseline and oxidative DNA damage in T2D patients were significantly decreased, as well as the frequency of micronuclei and nuclear buds. The fasting glucose levels, HDL and LDL cholesterol, and GGT levels that increased significantly in patients with type 2 diabetes were significantly reduced with nut consumption. Our results show an increase in antioxidant activity, along with reductions of protein and lipid oxidation as well as DNA damage, suggesting that Brazil nut consumption could be an ally in reducing oxidative stress and modulating the genomic instability in T2D patients.

Selenium Biomarkers and Their Relationship to Cardiovascular Risk Parameters in Obese Women

A cross-sectional study was carried out with 210 women divided into a case group (obese, n = 84) and a control group (eutrophic, n = 126). Body weight, height, waist circumference (WC), and hip and neck circumference were measured and the waist-hip ratio and conicity index were calculated. Selenium in plasma, erythrocytes and urine, erythrocyte GPx activity, lipid profile, Castelli I and II indices, and systolic and diastolic blood (DBP) pressure were evaluated. Mean dietary selenium intake (µg/kg/day) and plasma and erythrocyte concentrations were lower in the obese group compared to the healthy group (p < 0.001). while urinary selenium concentrations were higher (p < 0.001). There was a statistical difference between groups regarding cardiovascular risk parameters: waist circumference, neck circumference, waist-hip ratio, conicity index, triacylglycerols (TGC), and lipoproteins rich in triacylglycerols (VLDL-c) (p > 0.05). There was a negative correlation between plasma selenium concentrations and total cholesterol (TC), non-high-density lipoprotein (non-HDL), low-density lipoprotein (LDL-c), and systolic blood pressure (SBP). Urinary selenium correlated negatively with waist circumference and hip circumference and positively with neck circumference, TC, TGC, high-density lipoprotein (HDL-c), non-HDL, and VLDL-c. There was a negative correlation between dietary selenium and waist circumference, waist-hip ratio, neck circumference, conicity index, non-HDL cholesterol, LDL-c, and Castelli indices I and II, as well as a positive correlation with HDL-c and diastolic blood pressure. Women with obesity present changes in their nutritional status related to selenium, as well as increased cardiovascular risk parameters. Thus, the positive role of selenium in protecting the risk of cardiovascular disease is likely.

Supplementation of the maternal diet with Brazil nut (Bertholletia excelsa H.B.K.) prevents cognitive impairment in the offspring of obese mothers

Maternal obesity may trigger long-term neurodevelopmental disorders in offspring. Considering the benefits of the Brazil nut (Bertholletia excelsa H.B.K.), a rich source of nutrients such as selenium, this study aimed to evaluate its effect on the behavior of obese rat offspring and its relationship with oxidative stress. From 60 days of age until weaning, female Wistar rats were fed a high-fat diet (mHF) or an HF diet supplemented with 5% Brazil nut (mHF/BN), while control mothers (mCTL) were fed a standard diet or a standard diet supplemented with 5% Brazil nut (mBN). Male pups received a standard diet throughout life and, at 30 and 90 days old, were subjected to behavioral tasks to evaluate anxiety and cognition. Biochemical evaluations were performed at 90 days of age. No alterations were observed in the anxiety behavior of the offspring. However, the offspring of the mHF group (oHF) exhibited impaired short-term memory at 30 and 90 days of age and impaired long-term memory at 30 days. Short-term memory impairment was prevented by Brazil nuts in young rats (30 days). While the serum selenium concentration was reduced in the oHF group, the serum catalase concentration was reduced in all groups, without changes in lipid peroxidation or protein carbonylation. Brazil nut maternal diet supplementation prevented short- and long-term cognitive impairment in the offspring, which may be related to the selenium levels.

Arsenic exposure and increased C-reactive protein are independently associated with lower erythrocyte glutathione peroxidase activity in Bangladeshi children

Toxic metal contaminants present in food and water have widespread effects on health and disease. Chalcophiles, such as arsenic, cadmium, and mercury, show a high affinity to selenium and exposure to these metals could have a modulating effect on enzymes dependent on selenocysteine in their active sites. The aim of this study was to assess the influence of these metals on the activity of the selenoprotein glutathione peroxidase 1 (GPX1) in erythrocytes of 100 children residing in rural Bangladesh, where drinking water often contains arsenic. GPX1 expression, as measured using high-throughput immunoblotting, showed little correlation with GPX activity (rs = 0.02, p = 0.87) in blood samples. Toxic metals and selenium measured in erythrocytes using inductively coupled plasma mass spectrometry (ICP-MS) and C-reactive protein (CRP) measured in plasma, were all considered as effectors of this divergence in GPX enzymatic activity. Arsenic concentrations in erythrocytes were most influential for GPX1 activity (rs = -0.395, p < 0.0001), and CRP levels also negatively impacted GPX1 activity (rs = -0.443, p < 0.0001). These effects appear independent of each other as arsenic concentrations and CRP showed no correlation (rs = 0.124, p = 0.2204). Erythrocyte selenium, cadmium, and mercury did not show any correlation with GPX1 activity, nor with CRP or arsenic. Our findings suggest that childhood exposure to inorganic arsenic, as well as inflammation triggering the release of CRP, may negatively affect GPX1 activity in erythrocytes.

Effects of mixed nut consumption on LDL cholesterol, lipoprotein(a), and other cardiometabolic risk factors in overweight and obese adults

BACKGROUND AND AIMS

Elevated LDL-C, lipoprotein(a) [Lp(a)], and inflammation are associated with greater risk for atherosclerotic cardiovascular events. Consumption of individual nut types decreases these risk factors but knowledge about the effect of mixed nuts on Lp(a) is limited. The objective of this study was to determine the effects of consuming 42.5 g/day of mixed nuts on LDL-C, Lp(a), and inflammatory markers in individuals with overweight or obesity.

METHODS AND RESULTS

In a 16-week randomized control trial, 29 participants with overweight or obesity (BMI 25-40 kg/m²) consumed either 42.5 g/day of mixed nuts (cashews, almonds, macadamia nuts, Brazil nuts, pecans, pistachios, walnuts, and peanuts) or 69 g/day isocaloric pretzels. Blood samples were collected at baseline, week 8, and week 16 for analysis on total cholesterol (TC), LDL-C, Lp(a), inflammation markers, glucose, insulin, adiponectin and liver function enzymes. No significant differences were seen in TC, LDL-C, HDL-C, Lp(a), or liver function enzymes between the two groups. Participants consuming mixed nuts had significantly lower body fat percentage and diastolic blood pressure, and higher adiponectin (all P ≤ 0.05). C-reactive protein (CRP) and 8-oxo-deoxyguanosis (8-oxodG) showed non-significant decreasing trends and total antioxidant capacity (TAC) had a non-significant increasing trend in the mixed nut group.

CONCLUSION

Consumption of mixed nuts had no evidence of an effect on LDL-C or Lp(a) throughout the intervention. Notably, mixed nut consumption lowered body fat percentage without significant changes in body weight or BMI. Future studies with larger sample sizes investigating the changing trends of CRP, 8-oxodG, and TAC are warranted.

CLINICAL TRIAL REGISTER

NCT03375866.

Plasma Concentration of Essential and Toxic Trace Elements After Brazil Nut Intake: Results from a Randomized Controlled Trial

Brazil nut (BN) is a good source of essential nutrients, but little is known about the content of other components, such as toxic elements. Moreover, the high consumption of BN could probably contribute to increased levels of toxic and essential elements in the blood. Thus, this study aimed to evaluate the concentration of essential and toxic trace elements in BN and their concentration in plasma of obese women after regular intake of BN. A randomized controlled clinical trial was carried out with 55 subjects that were randomly assigned to either the Brazil nut group (BN) (n = 29) or the control group (CO) (n = 26) and followed up for 2 months. The BN group consumed one unit of Brazil nut per day, and the CO group did not receive any intervention. The concentration of essential elements (zinc, copper, manganese, and cobalt) and toxic (barium, lead, and cadmium) in BN samples and plasma of obese women (before and after the intervention) were determined by inductively coupled plasma mass spectrometry. Barium followed by copper, and manganese were the trace elements present in higher amounts in Brazil nuts. After the BN intervention period was observed an increase in plasma cadmium (p = 0.002) and a reduction of plasma manganese (p < 0.001) levels. In conclusion, our findings suggest that the regular consumption of BN from the Brazilian Amazon rainforest contributes to the intake of essential trace elements and can be considered safe regarding the content of heavy metals.

RELATIONSHIP BETWEEN SELENIUM NUTRITIONAL STATUS AND MARKERS OF LOW-GRADE CHRONIC INFLAMMATION IN OBESE WOMEN

Low-grade chronic inflammation is one of the main disorders that characterize adipose tissue dysfunction in obesity and is an important element in the pathogenesis of several comorbidities. In this context, selenium is an essential micronutrient that exerts important anti-inflammatory functions, and the role of selenium in controlling inflammation associated with obesity is not well defined. Thus, this study aimed to evaluate the relationship between markers of the nutritional status of selenium and low-grade chronic inflammation in obese women. This cross-sectional study included 81 women aged between 18 and 50 years, who were divided into two groups according to body mass index (BMI): the obesity group (n = 38) and normal weight group (n = 43). Selenium intake was assessed by 3-day diet records. The plasma, erythrocyte, and urinary selenium concentrations were determined using inductively coupled plasma optical emission spectrometry. The analysis of serum cytokines interleukin (IL)-8, IL-1β, IL-6, IL-10, and tumor necrosis factor alpha (TNFα) was performed using flow cytometry. The results of this study revealed that the obese women had higher dietary intake of selenium than eutrophic women. However, obese participants showed decreased selenium concentrations in plasma and erythrocytes, in parallel with increased concentrations of selenium in the urine. Regarding the inflammatory parameters, obese women exhibited higher concentrations of IL-6 and lower concentrations of the cytokines IL-8, IL-1β, and TNFα than eutrophic women. In the binary logistic regression analysis, erythrocyte selenium was considered an independent predictor of the serum concentrations of cytokine IL-8 in obese women, reflecting the anti-inflammatory action of this micronutrient.

Antitumor effect of selenium-rich Brazil nuts and selenomethionine dietary supplementation on pre-existing 4T1 mammary tumor growth in mice

Selenium (Se) is an essential micronutrient known to play an important role in the antioxidant system that can potentially influence tumor growth. We aimed to investigate the effects of dietary Se supplementation after detection of 4T1 mammary tumor growth in BALB/c mice. Thirty female mice received subcutaneous inoculation of 4T1 cells. After five days, all animals presenting palpable tumors were randomly assigned to three groups: a control group (Se-control) receiving a diet with adequate Se (0.15 mg/kg) and two other groups that received Se-supplemented diets (1.4 mg/kg of total Se) with either Brazilian nuts (Se-Nuts) or selenomethionine (SeMet). Data were assessed by either One or Two-way ANOVA followed by Tukey's HSD or Bonferroni's post hoc tests, respectively. Both Se-supplemented diets reduced tumor volume from the thirteenth day of feeding compared with the Se-adequate (control) diet (p < 0.05). The SeMet group presented a higher Se blood concentration (p < 0.05) than the Se-control group, with the Se-Nuts group presenting intermediate values. Selenoprotein P gene expression in the liver was higher in the Se-Nuts group than in the Se-control group (p < 0.05), while the SeMet group presented intermediate expression. Dietary Se supplementation, starting after detection of 4T1 palpable lesions, reduced tumor volume in mice.

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

The Brazil nut (BN) is a promising food due to its numerous health benefits, but it is still necessary to systematically review the scientific evidence on these benefits. Thus, we examined the effects of regular BN consumption on health markers in humans according to the health state (with specific diseases or not) of the subjects. PubMed, Embase^®, and Scielo databases were used to search for clinical trials. The PRISMA guideline was used to report the review, and the risk of bias for all studies was assessed. Twenty-four studies were included in the present review, of which fifteen were non-randomized. BNs were consumed in the context of a habitual free-living diet in all studies. Improvement in antioxidant status through increased levels of selenium and/or glutathione peroxidase activity in plasma, serum, whole blood, and/or erythrocytes was observed in all studies that evaluated antioxidant status, regardless of the health state of the sample. In addition, healthy subjects improved lipid markers and fasting glucose. Subjects with obesity had improvement in markers of lipid metabolism. Subjects with type 2 diabetes mellitus or dyslipidemia improved oxidative stress or DNA damage. Subjects undergoing hemodialysis benefited greatly from BN consumption, as they improved lipid profile markers, oxidative stress, inflammation, and thyroid function. Older adults with mild cognitive impairment improved verbal fluency and constructional praxis, and controversial results regarding the change in a marker of lipid peroxidation were observed in subjects with coronary artery disease. In conclusion, the benefits of BN consumption were found in different pathways of action and study populations.

Nutraceutical potential of Amazonian oilseeds in modulating the immune system against COVID-19 - A narrative review

Since the outbreak of COVID-19 disease, medical and scientific communities are facing a challenge to contain its spread, develop effective treatments, and reduce its sequelae. Together with the therapeutical treatments, the use of dietary bioactive compounds represents a promising and cost-effective strategy to modulate immunological responses. Amazonian oilseeds are great sources of bioactive compounds, thus representing not only a dietary source of nutrients but also of substances with great interest for human health. This narrative review compiled the available evidence regarding the biochemical properties of some Amazonian oilseeds, especially Brazil nut, Açaí berry, Bacaba, Peach palm, Sapucaya and Tucuma fruits, on human health and its immune system. These effects were discussed from an etiological and pathophysiological perspective, emphasizing their potential role as a co-adjuvant strategy against COVID-19. Besides this, the cost associated with these strategies hinders their applicability in many nations, especially low-income countries and communities living in social insecurity.

Supplementation of diet with Brazil nut modulates body composition, bone parameters, and lipid peroxidation in Wistar rats

Oxidative stress, adipose tissue, and bone compartments can be disturbed in chronic diseases. Non-pharmacological strategies, such as Brazil nuts (BNs), can improve these parameters. This study evaluated the effects of BN supplementation at different concentrations on body composition, lipid profile, and peroxidation in healthy rats. Male Wistar rats were divided into three groups: control (CT), Brazil nut 5% (BN5), and Brazil nut 10% (BN10) groups. Body composition, brown adipose tissue (BAT), plasma lipid peroxidation, and lipid profile were evaluated in the three groups. The BN5 group showed an improvement in all bone parameters compared with that of the CT group (p  < .0001). The BN5 and BN10 groups showed reduced plasma lipid peroxidation compared with that of the CT group (p = .0009), whereas the BN10 group presented lower BAT lipid peroxidation than that of the other groups (p = .01). High-density lipoprotein-cholesterol (HDL-c) levels were higher in the BN5 group than in the CT group (p = .01). Conclusively, the use of BNs in a controlled manner promoted improvement in bone parameters, HDL-c levels, and lipid peroxidation in healthy rats. PRACTICAL APPLICATIONS: Nuts has been included in the diet because of their versatility, acceptance, and easy access. Among them, Brazil nut (BN) is considered one of the major known food sources of selenium as well as a source of fibers, unsaturated fatty acids, and phenolic compounds. Studies have shown that BN supplementation is effective in reducing oxidative stress, inflammation, lipid peroxidation, and selenium deficiency when used as a non-pharmacological strategy in experimental models of chronic diseases and in clinical trials. The present study showed that controlled administration of BN improved bone parameters, high-density lipoprotein-cholesterol levels, and lipid peroxidation in healthy rats. Therefore, BN is a promising non-pharmacological agent for the prevention of the onset of chronic non-communicable diseases.

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

The purposes of this study were to assess the effect of Brazil nut supplementation on trimethylamine N-oxide (TMAO) levels and glutathione peroxidase (GPx) activity in patients with coronary artery disease (CAD). Patients with CAD were randomly assigned to two groups, Brazil nut group (23 patients, 48% male, 62.7 ± 6.8 years, 29.4 ± 5.8 kg/m² ), which received one Brazil nut per day for 3 months, and the control group (14 patients, 43% male, 63.7 ± 8.7 years, 28.4 ± 4.2 kg/m² ) who did not receive any supplementation. After 3 months, TMAO levels and their precursors did not change in either group. Although not significant, GPx activity increased by 41% in the Brazil nut group. TMAO levels were negatively associated with total fiber intake (r = -0.385 and p = .02). A 3-month Brazil nut supplementation did not change TMAO levels and GPx activity in CAD patients. PRACTICAL APPLICATIONS: Trimethylamine N-oxide (TMAO) has been associated with oxidative stress and cardiovascular disease risk. Thus, the increase in antioxidants enzymes production could be a promising strategy to reduce TMAO-mediated oxidative stress. In this context, nutritional strategies are well-known as activators of cellular antioxidant responses. As Brazil nuts have a known role in reducing oxidative stress by increasing glutathione peroxidase (GPx) activity (a selenium-dependent antioxidant enzyme), this study hypothesized that Brazil nuts could be a strategy that, via antioxidant capacity, would reduce TMAO plasma levels. Although no changes in TMAO levels and GPx activity can be observed in this study, it is believed that other results can be obtained depending on the dosage used. Thus, this study can open new paths and direct other studies with different doses and treatment times to evaluate the effects of Brazil Nuts on TMAO levels.

Nuts as a Part of Dietary Strategy to Improve Metabolic Biomarkers: A Narrative Review

Background

Nuts are in the spotlight because of their association with improved health outcomes. We aimed to summarize the findings of previous studies to evaluate the impact of nuts consumption on glycaemic and lipid profile, inflammation, and oxidative stress.

Methods

Electronic searches for observational and intervention studies were undertaken in PubMed, Embase, Web of Science, and Science Direct until 2022 for searching the studies aiming the application of different types of nuts and the beneficial effects of nuts in improving glycemia, dyslipidemia, inflammation, and oxidative stress.

Results

Results from 56 interventional, 9 narrative and 3 systematic reviews, and 12 meta-analysis studies, aiming at the evaluating beneficial effects of different types of nuts on metabolic markers, showed that nut consumption could improve metabolic markers, including glycaemic factors, lipid profile, and inflammatory and oxidative stress parameters in both healthy and individuals with metabolic disorders in a type-, dose- and duration-dependent manner. According to their unique nutrient components, nuts can be known as a part of a healthy diet, resulting in improved metabolic biomarkers.

Conclusion

Considering the efficacy of nuts in improving metabolic markers, incorporation of, incorporating nuts the effectiveness of nuts in improving metabolic markers, incorporating nuts in the diet may prevent the incidence or aggravation of chronic metabolic diseases. Considering the health benefits of the nuts' components, including essential micronutrients, if consumed in the appropriate dose and duration to provide the necessary amount of effective micronutrients to improve health, we will see an improvement in metabolic factors. At the same time, more research is required to determine the optimal type, dose, and duration of nut intervention with regards to metabolic control and reducing the risk of developing metabolic disorders.

Selenium in Brazil nuts: An overview of agronomical aspects, recent trends in analytical chemistry, and health outcomes

Se is an essential element in mammals. We review how its bioavailability in soil and the ability of plants to accumulate Se in foods depends on the soil Se profile (including levels and formats), besides to describe how the various selenoproteins have important biochemical functions in the body and directly impact human health. Owing to its favorable characteristics, the scientific community has investigated selenomethionine in most nut matrices. Among nuts, Brazil nuts have been highlighted as one of the richest sources of bioavailable Se. We summarize the most commonly used analytical methods for Se species and total Se determination in nuts. We also discuss the chemical forms of Se metabolized by mammals, human biochemistry and health outcomes from daily dietary intake of Se from Brazil nuts. These findings may facilitate the understanding of the importance of adequate dietary Se intake and enable researchers to define methods to determine Se species.

Brazil Nut (Bertholletia excelsa H.B.K) Retards Gastric Emptying and Modulates Enteric Glial Cells in a Dose-Dependent Manner

BACKGROUND

The role of food and nutrients in the regulation of enteric glial cell functions is unclear. Some foods influence enteric neurophysiology and can affect glial cell functions that include regulation of the intestinal barrier, gastric emptying, and colonic transit. Brazil nuts are the most abundant natural source of selenium, unsaturated fatty acids, fibers, and polyphenols.

OBJECTIVE

The study investigated the effects of a Brazil nut-enriched diet on enteric glial cells and gastrointestinal transit.

METHODS

Two-month-old male Wistar rats were randomized to a standard diet (control group, CG), standard diet containing 5% (wt/wt) Brazil nut (BN5), and standard diet containing 10% (wt/wt) Brazil nut (BN10) (n = 9 per group). After eight weeks, the animals underwent constipation and gastric emptying tests to assess motility. Evaluations of colonic immunofluorescence staining for glial fibrillary acidic protein (GFAP) and myenteric ganglia area were performed.

RESULTS

The BN5 group showed increased weight gain while the BN10 group did not (p < 0.0001). The BN10 group showed higher gastric residue amounts compared to the other groups (p = 0.0008). The colon exhibited an increase in GFAP immunoreactivity in the BN5 group compared to that in the other groups (p = 0.0016), and the BN10 group presented minor immunoreactivity compared to the CG (p = 0.04). The BN10 group presented a minor ganglia area compared to the CG (p = 0.0155).

CONCLUSION

The Brazil nut-enriched diet modified the gastric residual, colonic GFAP immunoreactivity, and myenteric ganglia area after eight weeks in healthy male Wistar rats.

Effect of different selenium sources and concentrations on glutathione peroxidase activity and cholesterol metabolism of beef cattle

The objective of this study was to investigate the effects of different Se sources and concentrations on glutathione forms and cholesterol metabolism in beef cattle. Sixty-three Nellore bulls (412 ± 19 kg BW; 24 months old) were randomly assigned to a completely randomized design in a 2×3 + 1 factorial arrangement (63 pens; one animal/pen) with two Se sources (sodium selenite, ING and Se-yeast, ORG), three concentrations (0.3, 0.9 and 2.7 mg supplemental Se/kg DM), and control treatment (without Se supplementation) fed for 90 days. Blood samples were collected on d 0, 28, 56, and 84. Muscle and liver samples were collected at harvest. Hepatic GSSG (P = 0.004), GSH/GSSG ratio (P = 0.030), and GSH-Px (P = 0.004) were affected by Se source x concentration interaction. Oxidized glutathione was higher in the ORG group vs. ING at concentration 2.7 mg supplemental Se/kg DM, but at 0.3 mg supplemental Se/kg DM the ING group was higher than ORG. The liver GSH-Px activity was higher in the ORG group vs. ING at concentration 0.9 and 2.7 mg supplemental Se/kg DM. The GSH/GSSG ratio was the highest in animals fed 0.3 mg supplemental Se/kg DM of ORG. Selenium liver concentration increased linearly with the supplemental Se concentration in the diet (y = 0.0583 + 0.4254x, R 2 = 0.92, P < 0.0001), regardless of source. Total meat cholesterol was greater (P < 0.001) in CON (control) vs. SUP (supplemented, regardless source) group. The muscle GSH-Px activity was higher (P < 0.001) in SUP vs. CON and increased (P < 0.004) with increasing supplemental Se concentrations. There was an increase on VLDL, glucose, and triglycerides in ORG vs. ING (P ≤ 0.035). In general, serum Se was higher (P < 0.001) in SUP vs. CON and increased with increasing supplemental Se concentration. Lastly, the HMGCR concentration was lower (P = 0.002) in SUP (0.39 ng/mL) vs. CON (0.55 ng/mL). Selenium supplementation with different sources and concentrations has the potential to affect cholesterol metabolism by affecting GSH/GSSG ratio, GSH-Px, and the HMGCR.

Oxidative Stress and Cognitive Decline: The Neuroprotective Role of Natural Antioxidants

Free- radicals (Oxygen and Nitrogen species) are formed in mitochondria during the oxidative phosphorylation. Their high reactivity, due to not-engaged electrons, leads to an increase of the oxidative stress. This condition affects above all the brain, that usually needs a large oxygen amount and in which there is the major possibility to accumulate "Reacting Species." Antioxidant molecules are fundamental in limiting free-radical damage, in particular in the central nervous system: the oxidative stress, in fact, seems to worsen the course of neurodegenerative diseases. The aim of this review is to sum up natural antioxidant molecules with the greatest neuroprotective properties against free radical genesis, understanding their relationship with the Central Nervous System.

Acute supplementation of growing rats with Brazil nut flour increases hepatic lipid content but prevents oxidative damage in the liver

Brazil nuts (BN) (Bertholletia excels, Bonpl.), are of great importance because of their nutritional properties and economic value. They can be consumed in natura or as flour (BNF). In this study, we evaluated the effects of BNF and BN intakes (Both 5% and 15%) on metabolic parameters of rats for 15 days. Serum Selenium (Se) levels were higher in BN-15% and BNF-15% groups. Lipid content was reduced in retroperitoneal and epididymal adipose tissues in all groups and in the BN-5% group in the liver. However, liver lipids increased in the BNF-15% group. The levels of carbonylated proteins and lipid peroxidation in the liver were not altered. The data reveal that the increase in hepatic lipids in the BNF-15% group probably occurred due to the high concentration of free fatty acids present in the flour. The Se bioavailability in the diet contributed to the preservation of the liver function in rats. PRACTICAL IMPLICATIONS: The consumption of BN is common in the population. However, changes in eating habits have led to a more frequent consumption of vegetable derivatives, such as drinks and oils. The cake residue generated after processing is still considered of high nutritional value, since it is a source of protein and minerals such as Se. Because of its low cost, the use of pie at the industrial level is becoming increasingly more interesting for the development of new products, and the Brazil nut flour (BNF) is considered a good option. Our study showed that just like BN, BNF can be a source of selenium for the body, although changes in lipid metabolism and physiological parameters can be observed depending on the amount used. We believe that the results of this investigation can be used to guide the development of new technologies and products containing BN.

Impact of Brazil Nut (Bertholletia excelsa, H.B.K.) Supplementation on Body Composition, Blood Pressure, and the Vascular Reactivity of Wistar Rats When Submitted to a Hypersodium Diet

Introdution: Endothelium integrity is a key that maintains vascular homeostasis but it can suffer irreversible damage by blood pressure changes, reflecting an imbalance in the maintenance of vascular homeostasis.Objective: The aim of this study was to investigate the impact of Brazil nut (Bertholletia excelsa, H.B.K.) (BN) supplementation (10% in chow, wt/wt) on the vascular reactivity of Wistar rats during chronic exposure to a sodium overload (1% in water).Methods: First, male Wistar rats were allocated into two groups: Control Group (CG) and the Hypersodic Group (HG) for 4 weeks. Afterward, the CG was divided into the Brazil Nut Group (BNG) and the HG Group into the Hypersodic Brazil Nut Group (HBNG) for a further 8 weeks, totaling 4 groups. Blood pressure was measured during the protocol. At the end of the protocol, the vascular reactivity procedure was performed. Glucose, lipid profile, lipid peroxidation, and platelet aggregation were analyzed in the serum. Body composition was determined by the carcass technique.Results: The groups that were supplemented with the BN chow presented less body mass gain and body fat mass, together with lower serum glucose levels. The HG Group presented an increase in blood pressure and a higher platelet aggregation, while the BN supplementation was able to blunt this effect. The HG Group also showed an increase in contractile response that was phenylephrine-induced and a decrease in maximum relaxation that was acetylcholine-induced when compared to the other groups.Conclusion: The BN supplementation was able to prevent an impaired vascular function in the early stages of arterial hypertension, while also improving body composition, serum glucose, and platelet aggregation.

Intersection between Obesity, Dietary Selenium, and Statin Therapy in Brazil

Obesity is among the most alarming health concerns, impacting public health and causing a socioeconomic challenge, especially in developing countries like Brazil, where approximately one quart of the population presents obesity. As an established risk factor for numerous comorbidities with a multifactorial etiology, obesity is a consequence of energy-dense overfeeding, however with significant undernourishment, leading to excessive adipose tissue accumulation and dysfunction, dyslipidemia, and micronutrient deficiencies. About 60% of patients with obesity take statins, a cholesterol-lowering medication, to curb dyslipidemia, with ~10% of these patients presenting various myopathies as side effects. Statins act upon the rate-limiting enzyme of cholesterol biosynthesis in the liver, which is a pathway providing intermediates to the synthesis of selenoproteins, i.e., enzymes containing the micronutrient selenium. Statins have been postulated to negatively impact selenoprotein synthesis, particularly in conditions of selenium deficiency, and potentially implicated in the myopathies occurring as side effects of statins. The Brazilian population is prone to selenium deficiency, hence could be considered more susceptible to statin side effects. This review examines the specific consequences to the Brazilian population of the harmful intersection between obesity development and concomitant micronutrient deficiencies, particularly selenium, combined with statin treatment in the context of nutrition in Brazil.

Selenium in Human Health and Gut Microflora: Bioavailability of Selenocompounds and Relationship With Diseases

This review covers current knowledge of selenium in the dietary intake, its bioavailability, metabolism, functions, biomarkers, supplementation and toxicity, as well as its relationship with diseases and gut microbiota specifically on the symbiotic relationship between gut microflora and selenium status. Selenium is essential for the maintenance of the immune system, conversion of thyroid hormones, protection against the harmful action of heavy metals and xenobiotics as well as for the reduction of the risk of chronic diseases. Selenium is able to balance the microbial flora avoiding health damage associated with dysbiosis. Experimental studies have shown that inorganic and organic selenocompounds are metabolized to selenomethionine and incorporated by bacteria from the gut microflora, therefore highlighting their role in improving the bioavailability of selenocompounds. Dietary selenium can affect the gut microbial colonization, which in turn influences the host's selenium status and expression of selenoproteoma. Selenium deficiency may result in a phenotype of gut microbiota that is more susceptible to cancer, thyroid dysfunctions, inflammatory bowel disease, and cardiovascular disorders. Although the host and gut microbiota benefit each other from their symbiotic relationship, they may become competitors if the supply of micronutrients is limited. Intestinal bacteria can remove selenium from the host resulting in two to three times lower levels of host's selenoproteins under selenium-limiting conditions. There are still gaps in whether these consequences are unfavorable to humans and animals or whether the daily intake of selenium is also adapted to meet the needs of the bacteria.

Amazon-derived nutraceuticals: Promises to mitigate chronic inflammatory states and neuroinflammation

Nutraceuticals have been the focus of numerous research in recent years and accumulating data support their use for promoting some health benefits. Several nutraceuticals have been widely studied as supplements due to their functional properties ameliorating symptoms associated with neurological disorders, such as oxidative stress and chronic inflammatory states. This seems to be the case of some fruits and seeds from the Amazon Biome consumed since the pre-Columbian period that could have potential beneficial impact on the human nervous system. The beneficial activities of these food sources are possibly related to a large number of bioactive molecules including polyphenols, carotenoids, unsaturated fatty acids, vitamins, and trace elements. In this context, this review compiled the research on six Amazonian fruits and seeds species and some of the major nutraceuticals found in their composition, presenting brief mechanisms related to their protagonist action in improving inflammatory responses and neuroinflammation.

The influence of nutrigenetics on biomarkers of selenium nutritional status

Selenium (Se) is an essential micronutrient for human biology that executes its functions as the amino acid selenocysteine via selenoproteins, which have important functions in, for example, antioxidation, immunomodulation, thyroid metabolism, and human fertility. Se nutritional status is assessed using the quantification of blood Se biomarkers, which are influenced by several factors, including diet, age, gender, smoking status, alcohol consumption, health condition, and the genetic characteristics of individuals. Nutrigenetic studies have identified single nucleotide polymorphisms in selenoproteins that might clarify the high variability in values reported for biomarkers of Se nutritional status in different populations, and the response of these biomarkers to Se supplementation with either organic or inorganic forms of Se. This review aims to (1) define the basic aspects of Se biology, (2) describe the current most commonly used biomarkers of Se nutritional status, and (3) provide a summary of associations between functional single nucleotide polymorphisms in selenoproteins and biomarkers of Se status in healthy populations.

Selenium Biofortification of Crop Food by Beneficial Microorganisms

Selenium (Se) is essential for human health, however, Se is deficient in soil in many places all around the world, resulting in human diseases, such as notorious Keshan disease and Keshin–Beck disease. Therefore, Se biofortification is a popular approach to improve Se uptake and maintain human health. Beneficial microorganisms, including mycorrhizal and root endophytic fungi, dark septate fungi, and plant growth-promoting rhizobacteria (PGPRs), show multiple functions, especially increased plant nutrition uptake, growth and yield, and resistance to abiotic stresses. Such functions can be used for Se biofortification and increased growth and yield under drought and salt stress. The present review summarizes the use of mycorrhizal fungi and PGPRs in Se biofortification, aiming to improving their practical use.

Benefits of the consumption of Brazil nut (Bertholletia excelsa) extract in male reproductive parameters of streptozotocin-induced diabetic rats

Objective

The objective of this study was to evaluate the effects of intake of Brazil nut extract (BN) or sodium selenite solution on reproductive parameters of male diabetic animals.

Methods

A total of 48 Wistar rats were distributed into six groups: diabetes (n = 8); diabetes and Brazil nut extract (n = 8); diabetes and sodium selenite (Na₂SeO₃) (n = 8); Brazil nut extract (n = 8); sodium selenite (n = 8) and control (n = 8). A single dose of streptozotocin (65 mg/kg) was injected intravenously to the rats to induce diabetes. BN or Na₂SeO₃ were administered by gavage for 56 days.

Results

The diabetes caused critical alterations on body mass gain, reproductive parameters and antioxidant capacity. Treatments with both BN or Na₂SeO₃ were able to increase significantly the glutathione peroxidase and the daily sperm production, both in diabetic (p < 0.01 and p < 0.05) and in healthy animals (p < 0.01 and p < 0.05).

Conclusion

The Brazil nut extract and sodium selenite were able to improve some reproductive parameters of diabetic rats. Moreover, we could infer that this effect is probably due to the natural selenium content of the BN.

Baru Almonds Increase the Activity of Glutathione Peroxidase in Overweight and Obese Women: A Randomized, Placebo-Controlled Trial

BACKGROUND

Obesity-induced inflammation is frequently associated with higher oxidative stress. In vitro and experimental studies have considered baru almonds (Dipteryx alata Vog) as a legume seed with high antioxidant capacity. The aim of this study was to evaluate whether baru almonds are capable of improving the inflammatory and antioxidant status in overweight and obese women.

METHODS

In a parallel-arm, randomized placebo-controlled trial, 46 overweight and obese women (age: 40 ± 11 years; body mass index: 33.3 ± 4.3) were randomly assigned to receive advice to follow a normocaloric and isoenergetic diet with placebo (PLA, n = 22) or similar advice plus 20 g baru almonds (BARU, n = 24) for 8 wk. Malondialdehyde (MDA), adiponectin, tumor necrosis factor-α, interleukin-6, interleukin-10, antioxidant enzymes activities (catalase-CAT; glutathione peroxidase-GPx; superoxide dismutase-SOD), and minerals were analyzed in plasma samples.

RESULTS

At baseline, groups were similar regarding the body composition, oxidative, and inflammatory parameters. The BARU group increased the activity of GPx (+0.08 U/mg, 95%CI + 0.05 to +0.12 vs. -0.07, 95%CI -0.12 to -0.03, p < 0.01) and plasma copper concentration (p = 0.037) when compared to the PLA group. No differences were observed between groups in CAT and SOD activity or MDA and cytokines concentrations.

CONCLUSIONS

Baru almond supplementation increased the GPx activity in overweight and obese women.

Performance, carcass characteristics and meat quality of Nellore cattle supplemented with supranutritional doses of sodium selenite or selenium-enriched yeast

The enrichment of meat with selenium is important to improve the intake of selenium by humans. The effects of supranutritional doses of sodium selenite or selenium-enriched yeast on performance, carcass characteristics and meat quality were evaluated using 63 Nellore cattle in a completely randomized design with two sources (sodium selenite and selenium-enriched yeast), three levels (0.3, 0.9 and 2.7 mg Se/kg DM) and control treatment (without addition of selenium). Final body weight (BW), average daily gain, dry matter intake and gain to feed ratio (G : F) at the end of 84 days of supplementation were not influenced by treatments (P>0.05). Values of pH, ribeye area, back fat thickness and marbling score were also not influenced by treatments ( P>0.05). Dressing percentage was greater (P=0.02) in Nellore cattle supplemented with organic Se (58.70%) compared to animals supplemented with inorganic Se (57.94%). Hot carcass weight increased ( P=0.05) with the increasing of Se levels in the diet. Colour, shear force (SF), cooking and drip loss remained unchanged ( P>0.05); however thiobarbituric acid reactive substances was 15.51% higher with inorganic Se compared with organic Se. The selenium concentration in the meat of animals receiving organic selenium was higher ( P<0.001) than that of animals receiving sodium selenite, at all levels (0.3; 0.9 and 2.7 mg/kg DM). The meat of animals receiving 2.7 mg of organic Se/kg of DM presented concentration of 372.7 μg Se/kg in the L.dorsi muscle, and the intake of 150 g of this meat by humans provides approximately 100% of the recommended Se intake (55 μg Se/day for adults). Therefore, the use of supranutritional doses of 2.7 mg Se/kg of DM, regardless of source, is a way of naturally producing selenium-enriched meat without compromising performance, carcass characteristics and quality of Nellore bovine meat.

Biomarkers of food intake for nuts and vegetable oils: an extensive literature search

Nuts and vegetable oils are important sources of fat and of a wide variety of micronutrients and phytochemicals. Following their intake, several of their constituents, as well as their derived metabolites, are found in blood circulation and in urine. As a consequence, these could be used to assess the compliance to a dietary intervention or to determine habitual intake of nuts and vegetable oils. However, before these metabolites can be widely used as biomarkers of food intake (BFIs), several characteristics have to be considered, including specificity, dose response, time response, stability, and analytical performance. We have, therefore, conducted an extensive literature search to evaluate current knowledge about potential BFIs of nuts and vegetable oils. Once identified, the strengths and weaknesses of the most promising candidate BFIs have been summarized. Results from selected studies have provided a variety of compounds mainly derived from the fatty fraction of these foods, but also other components and derived metabolites related to their nutritional composition. In particular, α-linolenic acid, urolithins, and 5-hydroxyindole-3-acetic acid seem to be the most plausible candidate BFIs for walnuts, whereas for almonds they could be α-tocopherol and some catechin-derived metabolites. Similarly, several studies have reported a strong association between selenium levels and consumption of Brazil nuts. Intake of vegetable oils has been mainly assessed through the measurement of specific fatty acids in different blood fractions, such as oleic acid for olive oil, α-linolenic acid for flaxseed (linseed) and rapeseed (canola) oils, and linoleic acid for sunflower oil. Additionally, hydroxytyrosol and its metabolites were the most promising distinctive BFIs for (extra) virgin olive oil. However, most of these components lack sufficient specificity to serve as BFIs. Therefore, additional studies are necessary to discover new candidate BFIs, as well as to further evaluate the specificity, sensitivity, dose-response relationships, and reproducibility of these candidate biomarkers and to eventually validate them in other populations. For the discovery of new candidate BFIs, an untargeted metabolomics approach may be the most effective strategy, whereas for increasing the specificity of the evaluation of food consumption, this could be a combination of different metabolites.

Consumption of Brazil nuts with high selenium levels increased inflammation biomarkers in obese women: A randomized controlled trial

OBJECTIVE

Increased inflammatory response is an important factor in the pathophysiology of obesity. The mineral selenium (Se), of which one of the main food sources is the Brazil nut, has important antioxidant and anti-inflammatory functions through the action of selenoproteins. Thus, the evaluation of the influence of this micronutrient in this context is of great relevance. The aim of this study was to evaluate the effects of Brazil nut intake with high Se concentrations on inflammatory biomarkers and its relation to Se status in obese women.

METHODS

A randomized controlled clinical trial was carried out with 55 women recruited at Clinical Hospital in São Paulo, Brazil. Patients were randomly assigned to either the Brazil nut group (BN) or the control group (CO) and followed up for 2 mo. The BN group consumed 1 unit/d of Brazil nuts (∼ 1261 μg/Se); the CO group did not receive any intervention. At baseline and after 2 mo, analysis of biochemical parameters related to Se status, oxidative stress, and inflammatory biomarkers were performed.

RESULTS

At baseline, both groups did not present Se deficiency. In the BN group, a significant increase (P < 0.05) in all Se biomarkers and in gene expression of several proinflammatory parameters (interleukin-6, tumor necrosis factor-α, and Toll-like receptors 2 and 4) were observed after the intervention period. No changes were observed for the CO group.

CONCLUSION

Although there were no changes in plasma inflammatory biomarkers levels, a significant increase in gene expression may be an indication of a proinflammatory stimulus in obesity, induced by the consumption of Brazil nuts with high Se levels.

Nutritional interventions and cognitive-related outcomes in patients with late-life cognitive disorders: A systematic review

There have been a large number of observational studies on the impact of nutrition on neuroprotection, however, there was a lack of evidence from randomized clinical trials (RCTs). In the present systematic review, from the 32 included RCTs published in the last four years (2014-2017) in patients aged 60 years and older with different late-life cognitive disorders, nutritional intervention through medical food/nutraceutical supplementation and multidomain approach improved magnetic resonance imaging findings and other cognitive-related biomarkers, but without clear effect on cognition in mild Alzheimer's disease (AD) and mild cognitive impairment (MCI). Antioxidant-rich foods (nuts, grapes, cherries) and fatty acid supplementation, mainly n-3 polyunsaturated fatty acids (PUFA), improved specific cognitive domains and cognitive-related outcomes in MCI, mild-to-moderate dementia, and AD. Antioxidant vitamin and trace element supplementations improved only cognitive-related outcomes and biomarkers, high-dose B vitamin supplementation in AD and MCI patients improved cognitive outcomes in the subjects with a high baseline plasma n-3 PUFA, while folic acid supplementation had positive impact on specific cognitive domains in those with high homocysteine.

Inflammation and kidney injury attenuated by prior intake of Brazil nuts in the process of ischemia and reperfusion

Introduction:

Ischemia and reperfusion (IR) is a process inherent to the procedures involved in the transplantation of organs that causes inflammation, cell death and cell injury, and may lead to rejection of the graft. It is possible that the anti-inflammatory properties of the Brazil nuts (BN) can mitigate the renal injury caused by IR.

Objective:

To investigate whether the previous intake of BN reduces the expression of markers of inflammation, injury, and cell death after renal IR.

Methods:

Male Wistar rats were distributed into six groups (N = 6/group): SHAM (control), SHAM treated with 75 or 150 mg of BN, IR, and IR treated with 75 or 150 mg of BN. The IR procedure consisted of right nephrectomy and occlusion of the left renal artery with a non-traumatic vascular clamp for 30 min. BN was given daily from day 1 to 7 before surgery (SHAM or IR), and maintained until sacrifice (48 h after surgery). Inflammation was evaluated by renal expression of COX-2 and TGF-β, injury by the expression of vimentin, and cell death by apoptosis through caspase-3 expression (immunohistochemistry).

Results:

Pretreatment with 75 mg of BN reduced renal expression of the COX-2, TGF-β, vimentin, and caspase-3. The dose of 150 mg caused increased expression of COX-2.

Conclusion:

In experimental IR, the damage can be minimized with a prior low-dose intake of BN, improving inflammation, injury, and cell death.

Total content and in vitro bioaccessibility of tellurium in Brazil nuts

Alongside the Brazil nut's role as an excellent source of vitamins, oil, fatty acids, lipids and nutrients, it is also recognized as a rich source of selenium. The pathway along which selenium and sulfur are metabolized in plants is theorized to be the same as that used for tellurium. Total tellurium content and its bioaccessibility are then evaluated by ICP-MS. Interferences and sample preparation are evaluated for the accurate determination of tellurium, and the accuracy determined through analysis of the certified reference material 1643e. A concentration of 4.02 ± 0.391 ng g^-1 is obtained as an average concentration through external and internal calibrations. Through this reliable result, tellurium bioaccessibility in Brazil nuts is obtained via an in vitro validated unified bioaccessibility method. Values of 32% and 30% of total tellurium are available in the gastric and gastrointestinal fractions, respectively.

Prior intake of Brazil nuts attenuates renal injury induced by ischemia and reperfusion

Introduction:

Ischemia-reperfusion (IR) injury results from inflammation and oxidative stress, among other factors. Because of its anti-inflammatory and antioxidant properties, the Brazil nut (BN) might attenuate IR renal injury.

Objective:

The aim of the present study was to investigate whether the intake of BN prevents or reduces IR kidney injury and inflammation, improving renal function and decreasing oxidative stress.

Methods:

Male Wistar rats were distributed into six groups (N=6/group): SHAM (control), SHAM treated with 75 or 150 mg of BN, IR, and IR treated with 75 or 150 mg of BN. The IR procedure consisted of right nephrectomy and occlusion of the left renal artery with a non-traumatic vascular clamp for 30 min. BN was given daily and individually for 7 days before surgery (SHAM or IR) and maintained until animal sacrifice (48h after surgery). We evaluated the following parameters: plasma creatinine, urea, and phosphorus; proteinuria, urinary output, and creatinine clearance; plasmatic TBARS and TEAC; kidney expression of iNOS and nitrotyrosine, and macrophage influx.

Results:

Pre-treatment with 75 mg of BN attenuated IR-induced renal changes, with elevation of creatinine clearance and urinary output, reducing proteinuria, urea, and plasmatic phosphorus as well as reducing kidney expression of iNOS, nitrotyrosine, and macrophage influx.

Conclusion:

Low intake of BN prior to IR-induced kidney injury improves renal function by inhibition of macrophage infiltration and oxidative stress.

Genetic variants in selenoprotein genes modulate biomarkers of selenium status in response to Brazil nut supplementation (the SU.BRA.NUT study)

BACKGROUND

The beneficial effects of selenium (Se) to human health are exerted by selenoproteins, which can be quantified in blood and used as biomarkers of Se status. Different responses of Se biomarkers after supplementation with selenomethionine and sodium selenite have been observed and some of them could be due to genetic polymorphisms, mainly single nucleotide polymorphisms (SNPs). Brazil nuts are known to be the richest natural source of Se.

OBJECTIVE

Investigate how genetic variations in selenoprotein genes modulate biomarkers of Se status in response to Brazil nut supplementation.

METHODS

The SU.BRA.NUT study was a four month interventional trial which involved healthy volunteers of both genders, selected in University of Sao Paulo. The supplementation was done with one Brazil nut a day for 8 weeks, followed by 8 weeks of washout. Blood samples were collected at 5 time points: baseline, 4 and 8 weeks of supplementation and 4 and 8 weeks of washout for analysis of five biomarkers of Se status - erythrocyte GPx1 (Glutathione Peroxidase 1) activity, plasma GPx3 activity, plasma Se, erythrocyte Se, and plasma selenoprotein P. The gene expression of GPX1, SELENOP, SELENOF and SELENOS was done before and after 8 weeks of supplementation. The volunteers were genotyped for SNPs in GPX1 (rs1050450, rs3811699 and rs1800699), GPX4 (rs713041), SELENOP (rs3877899 and rs7579), SELENOF (rs5845) and SELENOS (rs34713741).

RESULTS

A total of 130 volunteers finished the protocol. The concentrations of four biomarkers of Se status increased significantly after 4 and 8 weeks of supplementation, being modulated by gender. In addition, erythrocyte GPx1 activity was associated with rs1050450, rs713041 and rs5845. Plasma Se was associated with rs7579 and selenoprotein P with plasma Se at baseline. Nut supplementation significantly increased GPX1 mRNA expression only in subjects with CC genotype at rs1050450. SELENOP mRNA expression was significantly lower in subjects with GG genotype at rs7579 before and after supplementation.

CONCLUSION

Genetic variations in GPX1 and SELENOP genes are associated with different responses of molecular and biochemical biomarkers of Se status after Brazil nut supplementation in healthy Brazilians. The SU.BRA.NUT study was registred at www.clinicaltrials.gov as NCT 03111355.

Fingernail selenium levels in relation to the risk of obesity in Chinese children: A cross-sectional study

Selenium (Se) has been suggested to be beneficial to obesity development. However, limited studies have evaluated the association between Se and childhood obesity and the findings are inconsistent.The aim of this study was to examine the association of Se levels with obesity in children in a cross-sectional study.A total of 62 obese (21 girls) and 65 normal-weight children (27 girls) aged 7 to 13 years were recruited in Shanghai, China. Obesity was defined as body mass index (BMI) ≥ its 95th age- and sex-specific percentile for children. Participant demographic data and parental information were obtained through a self-administered questionnaire. Se concentration in fingernail clippings was quantified using flame atomic absorption spectrophotometry.The average age was 10.9 years (standard deviation = 1.0) and the mean BMI was 21.2 kg/m (standard deviation = 5.0). Fingernail Se levels were relatively higher among normal-weight children as compared with obese participants, though the difference was not statistically significant (P = .79). Se levels were inversely associated with the risk of childhood obesity after adjustment for potential confounders. The multivariable-adjusted odds ratio (95% confidence interval) was 0.24 (0.07-0.84) comparing participants in the highest with those who in the lowest tertile of Se levels (Plinear-trend = .03).Our study supported an inverse association between fingernail Se levels and the risk of obesity in Chinese children. Data generated from the present study are useful for designing future prospective cohort studies and/or randomized clinical trials.

Developmental selenium exposure and health risk in daily foodstuffs: A systematic review and meta-analysis

Selenium (Se) is a trace mineral and an essential nutrient of vital importance to human health in trace amounts. It acts as an antioxidant in both humans and animals, immunomodulator and also involved in the control of specific endocrine pathways. The aim of this work is to provide a brief knowledge on selenium content in daily used various foodstuffs, nutritional requirement and its various health consequences. In general, fruits and vegetables contain low content of selenium, with some exceptions. Selenium level in meat, eggs, poultry and seafood is usually high. For most countries, cereals, legumes, and derivatives are the major donors to the dietary selenium intake. Low level of selenium has been related with higher mortality risk, dysfunction of an immune system, and mental failure. Selenium supplementation or higher selenium content has antiviral outcomes and is necessary for effective reproduction of male and female, also decreases the threat of chronic disease (autoimmune thyroid). Generally, some advantages of higher content of selenium have been shown in various potential studies regarding lung, colorectal, prostate and bladder cancers risk, nevertheless results depicted from different trials have been diverse, which perhaps indicates the evidence that supplementation will merely grant advantage if the intakes of a nutrient is deficient. In conclusion, the over-all people should be advised against the usage of Se supplements for prevention of cardiovascular, hepatopathies, or cancer diseases, as advantages of Se supplements are still ambiguous, and their haphazard usage could result in an increased Se toxicity risk. The associations among Se intake/status and health, or disease risk, are complicated and need exposition to notify medical practice, to improve dietary recommendations, and to develop adequate communal health guidelines.

Natural variation of selenium in Brazil nuts and soils from the Amazon region

Brazil nut tree (Bertholletia excelsa) is native of the Amazon rainforest. Brazil nuts are consumed worldwide and are known as the richest food source of selenium (Se). Yet, the reasoning for such Se contents is not well stablished. We evaluated the variation in Se concentration of Brazil nuts from Brazilian Amazon basin, as well as soil properties, including total Se concentration, of the soils sampled directly underneath the trees crown, aiming to investigate which soil properties influence Se accumulation in the nuts. The median Se concentration in Brazil nuts varied from 2.07 mg kg^-1 (in Mato Grosso state) to 68.15 mg kg^-1 (in Amazonas state). Therefore, depending on its origin, a single Brazil nut could provide from 11% (in the Mato Grosso state) up to 288% (in the Amazonas state) of the daily Se requirement for an adult man (70 μg). The total Se concentration in the soil also varied considerably, ranging from <65.76 to 625.91 μg kg^-1, with highest Se concentrations being observed in soil samples from the state of Amazonas. Se accumulation in Brazil nuts generally increased in soils with higher total Se content, but decreased under acidic conditions in the soil. This indicates that, besides total soil Se concentration, soil acidity plays a major role in Se uptake by Brazil nut trees, possibly due to the importance of this soil property to Se retention in the soil.

Brazil nuts: Nutritional composition, health benefits and safety aspects

Brazil nuts are among the richest selenium food sources, and studies have considered this Amazonian nut as an alternative for selenium supplementation. Besides selenium, Brazil nuts present relevant content of other micronutrients such as magnesium, copper, and zinc. The nutritional composition of nuts, also characterized by adequate fatty acid profile and high content of protein and bioactive compounds, has many health benefits. In the present review, we examine the nutritional composition of Brazil nuts, comparing it with other nuts, and describe the relevance of possible contaminants and metal toxicants observed in this nut for human health. Furthermore, we report different trials available in the literature, which demonstrate positive outcomes such as modulation of the lipid serum profile, enhancement of the antioxidant system and improvement of anti-inflammatory response. These effects have been assessed under different conditions, such as cognitive impairment, dyslipidemia, cancer, and renal failure.

Influence of Genetic Variations in Selenoprotein Genes on the Pattern of Gene Expression after Supplementation with Brazil Nuts

Selenium (Se) is an essential micronutrient for human health. Its beneficial effects are exerted by selenoproteins, which can be quantified in blood and used as molecular biomarkers of Se status. We hypothesize that the presence of genetic polymorphisms in selenoprotein genes may: (1) influence the gene expression of specific selenoproteins and (2) influence the pattern of global gene expression after Brazil nut supplementation. The study was conducted with 130 healthy volunteers in Sao Paulo, Brazil, who consumed one Brazil nut (300 μg/Se) a day for eight weeks. Gene expression of GPX1 and SELENOP and genotyping were measured by real-time PCR using TaqMan Assays. Global gene expression was assessed by microarray using Illumina HumanHT-12 v4 BeadChips. Brazil nut supplementation significantly increased GPX1 mRNA expression only in subjects with CC genotype at rs1050450 (p < 0.05). SELENOP mRNA expression was significantly higher in A-carriers at rs7579 either before or after supplementation (p < 0.05). Genotype for rs713041 in GPX4 affected the pattern of blood cell global gene expression. Genetic variations in selenoprotein genes modulated both GPX1 and SELENOP selenoprotein gene expression and global gene expression in response to Brazil nut supplementation.

Glutathione peroxidase 4: a new player in neurodegeneration?

Glutathione peroxidase 4 (GPx4) is an antioxidant enzyme reported as an inhibitor of ferroptosis, a recently discovered non-apoptotic form of cell death. This pathway was initially described in cancer cells and has since been identified in hippocampal and renal cells. In this Perspective, we propose that inhibition of ferroptosis by GPx4 provides protective mechanisms against neurodegeneration. In addition, we suggest that selenium deficiency enhances susceptibility to ferroptotic processes, as well as other programmed cell death pathways due to a reduction in GPx4 activity. We review recent studies of GPx4 with an emphasis on neuronal protection, and discuss the relevance of selenium levels on its enzymatic activity.

Oilseeds native to the Cerrado have fatty acid profile beneficial for cardiovascular health

ABSTRACT Objective: To assess and compare the fatty acid composition of edible seeds and a nut native to the Cerrado (Brazilian savannah) to that of traditional oilseeds. Methods: Baru almonds, Cerrado cashew nuts, and pequi almonds were extracted from the fruits using appropriate equipment. All edible seeds and nuts were roasted, except for the Brazil nut. The sample lipids were extracted via cold pressing. The fatty acids were esterified, and the fatty acid esters were analyzed by gas chromatography. Results: The native and traditional edible seeds and nuts contain mostly monounsaturated fatty acids (42.72 g to 63.44 g/100 g), except for the Brazil nut, which showed predominance of polyunsaturated fatty acids (45.48 g/100 g). Pequi almond had the highest saturated fatty acid content (36.14 g/100 g). The fatty acids with the highest concentration were oleic and linoleic acids, and palmitic acid was also found in considerable concentration in the oilseeds studied. The Cerrado cashew nut and the traditional cashew nut have similar fatty acid profiles. As for the ratio of ω-6 to ω-3, the baru almond showed the highest ratio, 9:1, which was the closest to the recommended intake of these fatty acids. Conclusion: The fatty acid profile of the edible seeds and nuts native to the cerrado is similar to those of traditional oilseeds. We suggest the inclusion of native oilseeds in the diet aiming at reducing the risk of cardiovascular disease, especially the baru almond and the cerrado cashew nut, due to the fact they have high ratio of monounsaturated fatty acids to saturated fatty acids.

Biological functions of selenium and its potential influence on Parkinson's disease

Parkinson's disease is characterized by the death of dopaminergic neurons, mainly in the substantia nigra, and causes serious locomotor dysfunctions. It is likely that the oxidative damage to cellular biomolecules is among the leading causes of neurodegeneration that occurs in the disease. Selenium is an essential mineral for proper functioning of the brain, and mainly due to its antioxidant activity, it is possible to exert a special role in the prevention and in the nutritional management of Parkinson's disease. Currently, few researchers have investigated the effects of selenium on Parkinson´s disease. However, it is known that very high or very low body levels of selenium can (possibly) contribute to the pathogenesis of Parkinson's disease, because this imbalance results in increased levels of oxidative stress. Therefore, the aim of this work is to review and discuss studies that have addressed these topics and to finally associate the information obtained from them so that these data and associations serve as input to new research.