703 resultados para DIETARY ANTIOXIDANTS


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Reactive oxygen species (ROS) contribute significantly to myocardial ischaemia-reperfusion (I-R) injury. Recently the combination of the antioxidants vitamin E (VE) and alpha-lipoic acid (alpha-LA) has been reported to improve cardiac performance and reduce myocardial lipid peroxidation during in vitro I-R. The purpose of these experiments was to investigate the effects of VE and alpha-LA supplementation on cardiac performance, incidence of dysrhythmias and biochemical alterations during an in vivo myocardial I-R insult. Female Sprague-Dawley rats (4-months old) were assigned to one of the two dietary treatments: (1) control diet (CON) or (2) VE and alpha-LA supplementation (ANTIOXID). The CON diet was prepared to meet AIN-93M standards, which contains 75 IU VE kg(-1) diet. The ANTIOXID diet contained 10 000 IU VE kg(-1) diet and 1.65 g alpha-LA kg(-1) diet. After the 14-week feeding period, significant differences (P < 0.05) existed in mean myocardial VE levels between dietary groups. Animals in each experimental group were subjected to an in vivo I-R protocol which included 25 min of left anterior coronary artery occlusion followed by 10 min of reperfusion. No group differences (P > 0.05) existed in cardiac performance (e.g. peak arterial pressure or ventricular work) or the incidence of ventricular dysrhythmias during the I-R protocol. Following I-R, two markers of lipid peroxidation were lower (P < 0.05) in the ANTIOXID animals compared with CON. These data indicate that dietary supplementation of the antioxidants, VE and alpha-LA do not influence cardiac performance or the incidence of dysrhythmias but do decrease lipid peroxidation during in viva I-R in young adult rats.

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Objective: To illustrate methodological issues involved in estimating dietary trends in populations using data obtained from various sources in Australia in the 1980s and 1990s. Methods: Estimates of absolute and relative change in consumption of selected food items were calculated using national data published annually on the national food supply for 1982-83 to 1992-93 and responses to food frequency questions in two population based risk factor surveys in 1983 and 1994 in the Hunter Region of New South Wales, Australia. The validity of estimated food quantities obtained from these inexpensive sources at the beginning of the period was assessed by comparison with data from a national dietary survey conducted in 1983 using 24 h recall. Results: Trend estimates from the food supply data and risk factor survey data were in good agreement for increases in consumption of fresh fruit, vegetables and breakfast food and decreases in butter, margarine, sugar and alcohol. Estimates for trends in milk, eggs and bread consumption, however, were inconsistent. Conclusions: Both data sources can be used for monitoring progress towards national nutrition goals based on selected food items provided that some limitations are recognized. While data collection methods should be consistent over time they also need to allow for changes in the food supply (for example the introduction of new varieties such as low-fat dairy products). From time to time the trends derived from these inexpensive data sources should be compared with data derived from more detailed and quantitative estimates of dietary intake.

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Background: Dietary salt restriction has been reported to adversely modify the plasma lipoprotein profile in hypertensive and in normotensive subjects. We investigated the effects of the low sodium intake (LSI) on the plasma lipoprotein profile and on inflammation and thrombosis biomarkers during the fasting and postprandial periods. Methods: Non-obese, non-treated hypertensive adults (n=41) were fed strictly controlled diets. An initial week on a control diet (CID, Na=160 mmol/day) was followed by 3 weeks on LSI (Na=60mmol/day). At admission and on the last day of each period, the 24-h ambulatory blood pressure was monitored and blood was drawn after an overnight fasting period and after a fat-rich test meal. Results: The dietary adherence was confirmed by 24-h urinary sodium excretion. Fasting triglyceride (TG), chylomicron-cholesterol, hsC-reactive protein (CRP), tumor necrosis factor-a (TNF-alpha). interleukin-6 (IL-6) concentrations, renin activity, aldosterone, insulin, and homeostasis model assessment insulin resistance (HOMA-IR) Values were higher, but non-esterified fatty acids (NEFA) were lower on LSI than on CD. For LSI, areas under the curve (AUC) of TG, chylomicron-cholesterol, apoB and the cholesterol/apoB ratio were increased, whereas AUC-NEFA was lowered. LSI did not modify body weight, hematocrit, fasting plasma cholesterol, glucose, adiponectin, leptin, fibrinogen and factor VII (FVII), and AUC of lipoprotein lipase and of lipoprotein remnants. Conclusion: LSI induced alterations in the plasma lipoproteins and in inflammatory markers that are common features of the metabolic syndrome. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

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Purpose This study evaluated the effect of severe magnesium (Mg) dietary deficiency on systemic bone density and biomechanical resistance of bone tissue to the removal torque of osseointegrated implants Materials and Methods The sample consisted of 45 rats, each received a titanium implant in their tibial metaphysis After 60 days, the animals were divided into three groups (n = 15) according to their dietary Mg the control group received the recommended content of Mg, group Mg1 received a 75% reduction in dietary Mg content, and group Mg2 was fed a diet with a 90% reduction in Mg con tent Animals were sacrificed 150 days after implant placement Serum concentrations of Mg were measured and the effect of Mg deficiency on systemic bone density was evaluated by densitometry of the lumbar vertebrae and femur Biomechanical characteristics were measured by resistance of the bone tissue to removal of the implants Results Lower Mg serum concentrations were found for the Mg1 and Mg2 groups, however, densitometric analysis and torque evaluations showed a statistically significant difference only in the Mg2 group (P < 05) There was a statistically significant difference in removal torque between the Mg2 group and the control group Conclusions This study showed that a severe deficiency of Mg decreased the systemic bone density and removal torque of osseointegrated implants INT J ORAL MAXILLOFAC IMPLANTS 2010 25 1125-1130

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The aim of this study was to investigate the effect of supplementation of vitamin E, vitamin C, and zinc on the oxidative stress in burned children. In a prospective double-blind placebo-controlled pilot study, 32 patients were randomized as no supplementation (n = 15) or antioxidant supplementation (n = 17) groups. Supplementation consisted of the antioxidant mixture of vitamin C (1.5 times upper intake level), vitamin E (1.35 times upper intake level), and zinc (2.0 times recommended dietary allowance) administered during 7 days starting on the second day of admittance into the hospital. Energy requirement was calculated by the Curreri equation, and protein input was 3.0 g/kg of ideal body mass index (percentile 50 degrees). Total antioxidant capacity of plasma and malondialdehyde were used to monitor oxidative stress. The time of wound healing was evaluated as the main clinical feature. Patients (age 54.2 +/- 48.9 months, 65.6% males), who exhibited 15.5 +/- 6.7% of total burn area, showed no differences in age and sex, when compared with controls. Intake of the administered antioxidants was obviously higher in treated subjects (P = .005), and serum differences were confirmed for vitamin E and C, but not for zinc (P = .180). There was a decrease in lipid peroxidation (malondialdehyde level) (P = .006) and an increase in vitamin E concentrations in the antioxidant supplementation group (P = .016). The time of wound healing was lower in the supplemented group (P < .001). The antioxidant supplementation through vitamin E and C and the mineral zinc apparently enhanced antioxidant protection against oxidative stress and allowed less time for wound healing. (J Burn Care Res 2009;30:859-866)

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Background Diet seems to represent, directly or indirectly, 35% of all cancer reports. In this study, the influence of dietary protein on the growth of melanoma B16F10 was evaluated through analyses of cell cycle phases and proliferative capacity. Methods Flow cytometry and argyrophilic nucleolar organizer regions (AgNORs) technique were applied in mice bearing B16F10 melanoma cells fed on different dietary proteins. All data were submitted to statistical analyses. Results The G0/G1 phase increased for the animal groups fed bovine collagen hydrolysate (BCH) or BCH-P1 + whey protein isolate (WPI), compared with mice receiving only WPI, for all dietary groups treated and nontreated with paclitaxel. Mice that received BCH + WPI treated with paclitaxel showed the highest percentage of apoptosis compared with WPI group. AgNORs, total nucleolar organizer regions (NORs)/cells and dot number/cell for all dietary protein groups nontreated with paclitaxel were higher than for the WPI. The only two dietary protein groups treated with paclitaxel that presented higher total NORs and dot number/cell than the WPI group were BCH + WPI and BCH-P1 + WPI. Conclusions A significantly lower proliferative capacity and larger number of cells in the G0/G1 phase were observed for the dietary protein groups combining the two collagen hydrolysates, BCH or BCH-P1 with WPI, treated with paclitaxel. Castro GA, Maria DA, Rodrigues CJ, Sgarbieri VC. Analysis of cell cycle phases and proliferative capacity in mice bearing melanoma maintained on different dietary proteins.

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Patients with primary head and neck cancers have a higher risk of developing esophageal cancer. The aim of this study was to investigate esophageal cancer prevalence, its risk factors (ethanol and tobacco consumption) and dietary habits in patients with head and neck cancer. Three hundred and twenty-six adults with primary head and neck cancer were followed by a retrospective observational study in a general university hospital in Sao Paulo, Brazil. Flexible videoendoscopy with lugol chromoscopy was the method used to investigate esophageal cancer prevalence. All subjects were interviewed face-to-face, revealing detailed information about their tobacco and alcohol use, as well as their dietary habits. Thirty-six patients with esophageal cancer were diagnosed and the overall prevalence rate was 11.04%. Patients who developed second esophageal tumors had the following characteristics: earlier age of initial ethanol consumption (P < 0.05), longer duration period of ethanol consumption (P < 0.05) and higher weekly consumption rate (P < 0.05). There was an increased risk of esophageal carcinoma in those patients who both smoked and drank (P < 0.05). There was no association between carcinoma of the esophagus and dietary habits in patients who developed esophageal neoplasms, compared with those who did not. Prevalence rate of esophageal neoplasms was 11.04% in patients with head and neck carcinoma, whose ethanol consumption was associated with esophageal cancer. There was an increased risk between ethanol and tobacco consumption and esophageal carcinoma development. On the other hand, there was no association regarding dietary habits between patients who developed esophageal cancer and those who did not.

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We compared nutritional knowledge, eating attitudes and chronic dietary restraint scores among 17 men (10 with bulimia nervosa and 7 with anorexia nervosa) and 50 women (20 with bulimia nervosa and 30 with anorexia nervosa), who were consecutive patients at a major treatment center in Brazil. There were no differences in nutritional knowledge and concern with food between men and women. For both genders, chronic dietary restraint scores were higher among bulimics. Men with eating disorders had better eating attitudes scores than women. Anorexic men tended to have worse eating attitudes scores than bulimic men, while the opposite was observed for women, suggesting an interaction between gender and diagnosis. (C) 2009 Published by Elsevier Ltd.

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This study examined the effect of weight loss on energy intake, vitamin C, E, beta-carotene (diet/blood), reduced glutathione (GSH), C-reactive protein (CRP), thiobarbituric acid reactive substances (TBARS), catalase, and myeloperoxidase, in patients with Roux-en-Y bypass gastroplasty. Prospective clinical study with control (C) and bariatric (B) groups (n = 20 each). Age was 38.8 +/- 11.1 (C) and 37.8 +/- 11.2 years (B), and body mass indices (BMI) were 22.4 +/- 2.4 and 48.1 +/- 8.7 kg/m(2), respectively. Group C was assessed on a single occasion and B at three time points (basal period and 3 and 6 months after gastroplasty). BMI was decreased at three (38.3 +/- 1.7, P = 0.018) and 6 months after surgery (34.9 +/- 1.7, P < 0.001). Mean weight loss was 20.53 +/- 1.1 after three and 27.96 +/- 1.3 kg after 6 months. Serum vitamin C and beta-carotene (P < 0.01 and P < 0.001, respectively) were increased at 6 months compared to basal. Basal serum vitamin C (P = 0.001) and beta-carotene (P < 0.001) were lower compared to controls. Serum vitamin E corrected for cholesterol and triglycerides was higher in group B at three (P = 0.01) and 6 months (P = 0.001) and lower at basal (P < 0.001) compared to controls. GSH was higher in controls (P < 0.001) compared to basal. Catalase (P = 0.01) and TBARS (P < 0.001) were higher in group B at 6 months. TBARS were higher (P < 0.001) at basal compared to controls. Myeloperoxidase and CRP decreased in group B after three (P = 0.028, P = 0.010) and 6 months (P < 0.001, P = 0.001), respectively. Roux-en-Y bypass gastroplasty led to decreased proinflammatory parameters together with increased nutritional antioxidants, catalase, and TBARS, and decreased GSH 6 months after surgery.

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Dietary patterns have been related to health outcomes and morbi-mortality. Mediterranean diet indexes are correlated With adequate nutrient intake. The objective of the present study was to analyse the adequacy of nutrient intake of a posteriori defined Mediterranean (MDP) and Western (WDP) diet patterns in the Seguimiento Universidad de Navarra (SUN) cohort. A sample of 17 197 subjects participated in the study. Participants completed I 136-item validated semi-quantitative FFQ. Principal component analysis was used to define dietary patterns. Individuals were classified according to quintiles of adherence based on dietary pattern scores. Non-dietary variables, such as smoking and physical activity habits, were also taken into account. The probability approach was used to assess nutrient intake adequacy of certain vitamins (vitamins B(12), B(6), B(3), B(2), B(1), A, C, D and E) and minerals (Na, Zn, iodine, Se, folic acid, P, Mg, K, Fe and Ca). Logistic regression analysis was used to assess the adequacy of nutrient intake according to adherence to dietary patterns. WDP and MDP were defined. A higher quintile of adherence to an MDP was associated to I lower prevalence of inadequacy for the intake of Zn, iodine, vitamin E, Mg, Fe, vitamin B I, vitamin A, Se, vitamin C and folic acid. The adjusted OR for not reaching at least six (or at leas( ten) nutrient recommendations were 0.09 (95% Cl: 0.07, 0.11) (and 0.02 (95% Cl: 0.00, 0.16)) for the upper quintile of MDP and 4.4 (95% Cl: 3.6, 5.5) and 2.5 (95 % Cl: 1.1, 5.4) for the WDP. The MDP was associated to a better profile of nutrient intake.

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Objective: This study aimed to assess the relative validity of a food frequency questionnaire.(FFQ), previously validated to measure usual intakes in adults, for measuring dietary intakes in children 5 to 10 y of age. Methods: Dietary intakes were measured using an FFQ and a 3-d dietary record. Healthy children, 5 to 10 y old (n = 151), were recruited from public schools and asked to answer the questions in the FFQ and to provide non-consecutive 3-d dietary records based on reported estimated portion sizes. Paired sample t tests and Pearson`s correlation coefficients were conducted to determine whether the two instruments reported similar values for energy and nutrients. The agreement of quartile categorization between the two instruments was also examined. Results: Estimated energy and nutrient intakes derived from the FFQ were significantly higher than those derived from 3-d dietary records. As expected, Pearson`s correlations increased after adjusting for residual measurement error, presumably due to exclusion of the high within-person variability in intake of these nutrients. Moderate to high (r > 0.50) correlation coefficients were verified for some nutrients such as calcium, folate, vitamin 132, vitamin A, and vitamin C. Conclusion: This FFQ, originally developed for use in adults, appears to overestimate usual energy and nutrient intakes in children 5 to 10 y of age. Further work is necessary to conduct a calibration study to establish adequate portion sizes before instrument adoption in this population. (c) 2008 Elsevier Inc. All rights reserved.

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Dietary nitrite and nitrate are important sources of nitric oxide (NO). However, the use of nitrite as an antihypertensive drug may be limited by increased oxidative stress associated with hypertension. We evaluated the antihypertensive effects of sodium nitrite given in drinking water for 4 weeks in two-kidney one-clip (21(1 C) hypertensive rats and the effects induced by nitrite on NO bioavailability and oxidative stress. We found that, even under the increased oxidative stress conditions present in 2K1C hypertension, nitrite reduced systolic blood pressure in a dose-dependent manner. Whereas treatment with nitrite did not significantly change plasma nitrite concentrations in 2K1C rats, it increased plasma nitrate levels significantly. Surprisingly, nitrite treatment exerted antioxidant effects in both hypertensive and sham-normotensive control rats. A series of in vitro experiments was carried out to show that the antioxidant effects induced by nitrite do not involve direct antioxidant effects or xanthine oxidase activity inhibition. Conversely, nitrite decreased vascular NADPH oxidase activity. Taken together, our results show for the first time that nitrite has antihypertensive effects in 2K1C hypertensive rats, which may be due to its antioxidant properties resulting from vascular NADPH oxidase activity inhibition. (C) 2011 Elsevier Inc. All rights reserved.

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Caloric intake reduction has been considered as the major experimental manipulation able to increase longevity in experimental models. Therefore, its effects upon cognition and mood like behavior are poorly explored. On the other hand, Li(+) is a re-emergent therapeutic drug used to treat mood disorders, mainly bipolar disorder, with antipanic and antidepressant actions. On the hypothesis that lithium treatment could attenuate the negatives effects of stress on Central Nervous Systems (CNS), we evaluated the role of chronic lithium treatment on anxiety-like behaviors in animals submitted to stress by chronic moderated feed restriction (FR). Male wistar rats were divided into four groups (n = 7-8/group) according to dietary and drug manipulation: ad libitum (AL) with unlimited access to standard rat diet, lithium treatment ( AL + Li) which received approximately 50 mg/Kg animal/day of LiCl solved in water and ad libitum diet, FR that were fed with equivalent to 70% of total rat diet consumed by AL group, and FR + Li which received diet corresponding to FR and Li administration. After 12 weeks of drug and FR manipulation, anxiety like behavior was evaluated in elevated plus mazes (EPM). Chronic lithium treatment prevent the anxiogenic like effect of FR ( open time, F(3,30) = 3.588; P = 0.0265; percentage of open entries, F(3,30) = 6.004; P= 0.00029; and open time at the first min, 2.35; F(3,30) = 4.937; P = 0.0073, Duncan test P < 0.05) compared to AL diet. Ours results adding to evidences that moderate feed restriction my increase anxiety-like behavior; also suggest that chronic lithium treatment may be attenuated this effects.