O estresse oxidativo decorre de um desequilíbrio entre a geração de compostos oxidantes e a atuação dos sistemas de defesa antioxidante. A geração de radicais livres e/ou espécies reativas não radicais é resultante do metabolismo de oxigênio. A mitocôndria, por meio da cadeia transportadora de elétrons, é a principal fonte geradora. O sistema de defesa antioxidante tem a função de inibir e/ou reduzir os danos causados pela ação deletéria dos radicais livres e/ou espécies reativas não radicais. Esse sistema, usualmente, é dividido em enzimático (superóxido dismutase, catalase e glutationa peroxidase) e não-enzimático. No último caso, é constituído por grande variedade de substâncias antioxidantes, que podem ter origem endógena ou dietética. Objetivou-se revisar os principais mecanismos de geração de radicais livres, bem como a ação dos agentes mais relevantes do sistema de defesa antioxidante, ressaltando suas implicações sobre os marcadores do estresse oxidativo. Também serão abordados os principais fatores exógenos moduladores do estresse oxidativo. Termos de indexação:Antioxidantes. Espécies reativas de nitrogênio. Espécies reativas de oxigênio. Estresse oxidativo. Radicais livres.

BackgroundDietary total antioxidant capacity (TAC) has been assumed as a useful tool to assess the relationship between the cumulative antioxidant food capacity and several chronic disorders. The aim of this cross-sectional study was to investigate the potential relationships of dietary TAC with adiposity, metabolic and oxidative stress markers in healthy young adults.MethodsThis study enrolled 266 healthy subjects (105 men/ 161 women; 22 ± 3 years-old; 22.0 ± 2.7 kg/m2). Dietary intake, anthropometry, blood pressure, lifestyle features, and biochemical data were assessed with validated procedures.ResultsIn linear regression analyses, dietary TAC values were inversely associated with glycemia, total cholesterol:HDL-c ratio, triglycerides and oxidized-LDL concentrations, and positively associated with HDL-c concentrations, independently of gender, age, smoking status, physical activity, vitamin use supplement, waist circumference, energy intake, fatty acid intake. In addition, plasma TAC was negatively correlated with ox-LDL concentrations (r= -0.20, P = 0.003), independently of the assessed confounding variables. Finally, dietary TAC values were inversely related to waist circumference values (r= -0.17, P = 0.005) as well as to lower mild central obesity occurrence (waist circumference ≥ 80/ 94 cm for women/ men, respectively).ConclusionDietary TAC values are inversely associated with glucose and lipid biomarkers as well as with central adiposity measurements in healthy young adults, indicating dietary TAC as a useful tool to assess the health benefits of cumulative antioxidant capacity from food intake. In addition, the independent and inverse relationships of ox-LDL concentrations with dietary and plasma TAC respectively suggest a putative role of antioxidant rich-diet in the link between redox state and atherogenesis at early stage.

Mg depletion is common in poorly controlled patients with type 2 diabetes, especially in those with neuropathy or coronary disease. More prolonged use of Mg in doses that are higher than usual is needed to establish its routine or selective administration in patients with type 2 diabetes to improve control or prevent chronic complications.

a b s t r a c tAntimicrobial packaging, besides protecting the product from external environment, inhibits or retards microorganism growth in foods, minimizing direct addition of preservatives and satisfying the actual demand of consumers for healthier foods, containing less additives. Pediocins are antimicrobial peptides produced by Pediococcus sp. and researches have revealed their ability to inhibit the growth of some pathogenic bacteria. The objective of this work was to develop and evaluate the antimicrobial efficiency of films incorporated with pediocin on sliced ham conservation. The antimicrobial films were incorporated with pediocin (25% and 50%) in a cellulose base emulsion. The antimicrobial efficiency of the films against Listeria innocua e Salmonella sp. on sliced ham was tested by means of a challenge test, in which the slices were immersed in 0.1% peptone solution containing about 10 6 CFU/mL of L. innocua or Salmonella sp. The experiment was set up overlapping the slices of ham with the films (control, 25% and 50% of pediocin). These systems were packaged under vacuum and stored at 12°C. The slices of ham were analyzed for L. innocua and Salmonella sp. counts at 0, 3, 6, 9, 12 and 15 storage days. The antimicrobial films were more effective inhibiting growth of L. innocua. The 50% pediocin-film presented a reduction of 2 log cycles in relation to control treatment after 15 days of storage. The 25% and 50% pediocin-films had similar performance on Salmonella sp. inhibition, both presenting 0.5 log cycle reduction in relation to control, after 12 days of storage. Hence, the films incorporated with pediocin showed potential use as one hurdle technology added in the storage period among others good manufacturing practices for preservation of sliced ham.

Os fenômenos puberais apresentam variabilidade no que diz respeito às idades de início e término, à velocidade e magnitude com que se expressam e as suas inter-relações. Tais fenômenos influenciam as modificações antropométricas e de composição corporal que caracterizam o processo de crescimento e desenvolvimento da adolescência. O artigo tem como objetivo analisar a influência dos estágios de maturação sexual, no estado nutricional, antropometria e composição corporal de adolescentes de ambos os sexos. A revisão de literatura foi realizada utilizando-se os termos "Adolescent, Puberty and Body Composition", por meio de consulta na base de dados do HighWire Press®. Trabalhou-se com artigos publicados desde janeiro de 1995 até julho de 2006, incluindo, outros relevantes ao tema, publicados anteriormente. Na adolescência, para se avaliar o estado nutricional e as modificações antropométricas e de composição corporal, é de extrema importância a consideração não somente da idade cronológica, mas também do estágio de maturação sexual. Cabe ressaltar as consideráveis dificuldades metodológicas existentes nos estudos acerca do estadiamento pubertário. Destaca-se a importância da realização de mais estudos, no sentido de elucidar a influência dos estágios de maturação sexual na evolução dos parâmetros antropométricos e de composição corporal, possibilitando a construção e utilização sistemática de referências que considerem o desenvolvimento pubertário.

The aim of the present cross-sectional study was to assess the potential relationships between fruit and vegetable (FV) consumption and some oxidative stress markers in young adults, with particular emphasis on fibre and vitamin C intake. The study enrolled 246 healthy subjects (eighty-eight men and 158 women), with a mean age of 22 (SD 3) years and a mean BMI of 21·9 (SD 2·8) kg/m 2 . Dietary intake, anthropometry, blood pressure, lifestyle features and blood biochemical data were assessed with validated procedures. Those subjects in the highest tertile (T) of FV consumption ($705 g/d) had statistically lower oxidised LDL (ox-LDL) concentrations as well as higher plasma total antioxidant capacity (TAC) and glutathione peroxidase (GPx) activity (P for trend ,0·05), after adjusting for sex, age, energy intake, physical activity, smoking, BMI, vitamin supplement use and other confounding factors. Moreover, plasma ox-LDL concentrations showed a decreasing trend and TAC an increasing trend across tertiles of fibre (T3: $14 g/d) and vitamin C (T3: $ 150 mg/d) from FV intake, while GPx activity was positively associated with vitamin C intake (P for trend , 0·05). In conclusion, greater FV consumption was independently associated with reduced ox-LDL as well as increased TAC and GPx activity in healthy young adults, with dietary fibre and vitamin C from FV clearly being implicated in this beneficial relationship.

Past research has shown the importance of zinc in several metabolic processes, such as the glucidic metabolism. The present systematic review aims to discuss zinc's participation in the glycemic control of type 2 diabetes mellitus (DM2) patients. In order to accomplish that, a systematic search was performed in the Pubmed database using the following indexed and theme-related descriptors: "zinc" AND "type 2 diabetes mellitus", AND MeSH terms related to glycemic control combined with the boolean operator OR. In total, 1078 articles were retrieved from the research, of which 15 articles of original studies conducted with DM2 patients were included, with three being about the effect of mineral supplementation and 12 reporting observational studies. The main findings of these studies consisted of low body contents of zinc and high excretion of zinc in urine. Hyperglycemia was one of the mechanisms that caused these alterations owing to its interference in zinc reabsorption via renal cells. Another evidence was the negative correlation between the glycated hemoglobin percentage (%HbA1c) and the plasma zinc levels. Additionally, it has been observed that zinc supplementation in DM2 patients has improved glycemic control, since the %HbA1c significantly reduced in these individuals. This present review shows the positive effect of adequate zinc levels on glycemic control, whether it is through dietetic ingestion or supplementation, since its role in insulin homeostasis is clear.

Objective: To assess whether higher adherence to the traditional Mediterranean diet (MedDiet) was associated with lower consumption of ultra-processed foods (UPF) and lower free sugar intake. Design: Cross-sectional analysis of baseline information among participants in the SENDO project, a Spanish paediatric cohort. Dietary information was collected through a semi-quantitative FFQ. Food items were classified according to the NOVA classification. Adherence to the MedDiet was evaluated through the KIDMED index. Setting: Spain. Participants: Three hundred eight-six children (52 % boys) with a mean age of 5·3 years old (sd 1·0) were included in the analysis. Results: 74·4 % of the children had moderate adherence to the MedDiet (mean KIDMED score: 5·9 points; sd 1·7) and overall, 32·2 % of the total energy intake came from UPF. Each two additional points in the KIDMED score was associated with 3·1 % (95 % CI 2·1, 4·0) lower energy intake from UPF. Compared to those with low adherence to the MedDiet, children with medium and high adherence reported 5·0 % (95 % CI 2·2, 7·7) and 8·5 % (95 % CI 5·2, 11·9) lower energy intake from UPF, respectively. We also found that 71·6 % of the variability in free sugar intake was explained by the variability in UPF consumption. Conclusions: Adherence to the traditional MedDiet was inversely associated with energy intake from UPF. Furthermore, most of the variability in free sugar intake was explained by the variability of UPF consumption. Public health strategies are needed to strengthen the adherence to the MedDiet in pre-schoolers while regulating the production, marketing and advertising of UPF.