Maritsa Carla de Bortoli

Associations between glutathione peroxidase-1 Pro198Leu polymorphism, selenium status, and DNA damage levels in obese women after consumption of Brazil nuts

OBJECTIVE Alterations in selenium (Se) status may result in suboptimal amounts of selenoproteins, which have been associated with increased oxidative stress levels. The Pro198Leu polymorphism at the glutathione peroxidase-1 (GPx1) gene is supposed to be functional. The response of Se status, GPx activity, and levels of DNA damage to a Se supplementation trial between the genotypes related to that polymorphism was investigated. METHODS A randomized trial was conducted with 37 morbidly obese women. Participants consumed one Brazil nut, which provided approximately 290 μg of Se a day, for 8 wk. Blood Se concentrations, erythrocyte GPx activity, and DNA damage levels were measured at baseline and at 8 wk. The results were compared by genotypes. RESULTS The genotype frequencies were 0.487, 0.378, and 0.135 for Pro/Pro (the wild-type genotype), Pro/Leu, and Leu/Leu, respectively. At baseline, 100% of the subjects were Se deficient, and after the supplementation, there was an improvement in plasma Se (P < 0.001 for Pro/Pro and Pro/Leu, P < 0.05 for Leu/Leu), erythrocyte Se (P = 0.00 for Pro/Pro and Pro/Leu, P < 0.05 for Leu/Leu), and GPx activity (P = 0.00 for Pro/Pro, P < 0.00001 for Pro/Leu, P < 0.001 for Leu/Leu). In addition, the Pro/Pro group showed a decrease in DNA damage after Brazil nut consumption compared with baseline (P < 0.005), and those levels were higher in Leu/Leu subjects compared with those with the wild-type genotype (P < 0.05). CONCLUSION Consumption of one unit of Brazil nuts daily effectively increases Se status and increases GPx activity in obese women, regardless of GPx1 Pro198Leu polymorphism. However, the evaluated biomarkers showed distinct results in response to the supplementation when the polymorphism was considered.

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

Studies have shown that there are inverse relationships between nut consumption and the reduction of cardiovascular risk. This study tested the hypothesis that daily consumption of Brazilian nuts would have a positive effect upon selenium (Se) status, erythrocyte glutathione peroxidase activity, lipid profile, and atherogenic risk in severely obese women. Thirty-seven severely obese women each consumed 1 Brazilian nut a day (290 μg of Se a day) for 8 weeks. Blood Se concentrations, total erythrocyte glutathione peroxidase activity, lipid profile, and Castelli I and II indexes were evaluated before and after the nuts consumption. All the patients were Se deficient at baseline; this deficiency was remedied by the consumption of the Brazilian nut (P < .0001). The intake of Brazilian nuts promoted a significant increase in high-density lipoprotein cholesterol concentrations (P < .00001), which then resulted in a significant improvement of the Castelli I (P < .0002) and II (P < .0004) indexes. This study shows that obese people who implement daily consumption of Brazilian nuts can improve both Se status and lipid profile, especially high-density lipoprotein cholesterol levels, thereby reducing cardiovascular risks.

Selenium status and hair mercury levels in riverine children from Rondônia, Amazonia

OBJECTIVE Riverine communities in Rondônia State are exposed to high selenium (Se) content in their diet because of the high-selenium soils identified in the Amazon. However, the Amazonian population has a high mercury (Hg) exposure because this metal accumulates in the soil. Because children are more vulnerable to Hg toxicity, the aim of this study was to evaluate and correlate Se status and hair Hg levels in riverine children (aged 3-9 y) living in two different locations in Rondônia State: Demarcação area (DA) and Gleba do Rio Preto (GRP). METHODS Se levels were assessed using hydride generation quartz tube atomic absorption spectroscopy; total hair Hg levels were assessed using cold vapor atomic absorption spectrometry. Dietary intake was evaluated through a 24-h food record and a food frequency questionnaire. RESULTS Forty-two children participated in this study. Eighty-four percent of the children from DA showed low plasma Se. Conversely, all children from GRP presented plasma Se levels above the reference values. Forty-five percent of the children from DA presented low erythrocyte levels, and 55% of the children from GRP showed concentration in erythrocyte above the reference values. The mean Se intake was 41.8 μg/d in DA and 179.0 μg/d in GRP. High hair Hg levels were observed in children from both the DA and GRP (3.57 ± 1.86 and 6.24 ± 5.89, respectively). CONCLUSIONS Children from both riverine communities are likely to present altered Se status according to their dietary intake. Additionally, these children are highly exposed to Hg, mainly through fish consumption, and the toxicity of this metal may cause metabolic damage.

Zinc and selenium nutritional status in vegetarians.

A vegetarian diet may have beneficial effects on human health, however when it is not well-balanced may be deficient in some nutrients, as minerals for example. The aim of the present study was to assess the nutritional status of zinc and selenium in vegetarians in the city of São Paulo. A cross-sectional study was performed, and the inclusion criteria were age ≥ 18 years, both gender, no use of food or pharmaceutical supplements. Thirty vegetarian, of both genders, mean age of 27 years and 4,5 years of vegetarianism had performed the study, and their mean BMI was 21,5. Zinc plasma concentration was 71 and 62,5 μg/dL for men and women and erythrocyte concentration was 37 μg/gHb for both genders. Selenium concentration was 73,5 and 77,3 μg/L in plasma and 51,4 and 66,9 μg/L in erythrocytes for men and women, respectively. These biochemical values show that, according to the references, selenium blood levels are adequate and zinc concentration in erythrocytes is deficient in the studied population. For this reason, vegetarians should be constantly assessed and receive nutritional support to reduce the effects of inadequate zinc status.

Caracterização química e radiológica de refeições servidas pelo COSEAS/USP-SP

This study presents the results obtained for the chemical and radiological analyses of lunch meals served in the cafeteria at the University of Sao Paulo-USP (COSEAS restaurant) in Brazil, on 5 non-consecutive days. On each of the five days, the meals were collected in triplicate and then freeze-dried for analysis totalizing 15 samples. The determination of the proximate composition complied with the AOAC standardized methodologies. The content of Ca, Fe, K, Na, Se, and Zn was determined by instrumental neutron activation analysis and the method validation was performed by certified reference materials analyses. Based on the concentration data, the daily intake of each mineral was calculated (corresponding to 40% of the total daily intake) and compared to the new recommendations set by the National Research Council (USA) considering the 19-30 year-old women range group. Comparing the average values obtained in this study with the recommended values, it was possible to verify that for macronutrients and the micronutrients Fe, Se, and Zn the recommendations were followed; for Ca and K they were deficient and exceeded the recommendation value for Na. The radionuclides 40K, 60Co, 137Cs, and 131I were determined by gamma spectrometry; 90Sr by liquid cintilation and 210Po, 234U, 232Th, 238U, 235U, 228Th, 230Th, and 232Th by alfa spectrometry. All radionuclides are present in concentrations below the limits set by the Food and Agriculture Organization (FAO).