Effect of mate tea (Ilex paraguariensis) on the expression of the leukocyte NADPH oxidase subunit p47phox and on circulating inflammatory cytokines in healthy men: a pilot study.

Increased superoxide production by phagocytic NADPH oxidase has been associated with inflammatory conditions. Growing evidences suggest that dietary polyphenols may modulate the expression of NADPH oxidase subunits. Herein, we examined whether soluble mate tea (SMT) consumption - a polyphenol-rich beverage - affects the expression of the leukocyte NADPH oxidase protein p47phox and/or circulating biomarkers of inflammation and antioxidant biomarkers in humans. In a two-phase study, nine men were requested to drink water (control) for 8 d and then follow a second 8-d period drinking SMT. Blood samples were analysed for p47phox protein in CD16+/CD14- cells, interleukin (IL)-1ß (IL-1ß), tumour necrosis factor-alpha (TNF-α), IL-6, total phenols, and reduced and oxidised glutathione (GSH and GSSG, respectively) after each study phase. After SMT intake, CD16+/CD14- cells' p47phox protein and serum TNF-α and IL-6 levels were significantly attenuated (P < .05) while plasma phenolic compounds and blood GSH:GSSG ratio were significantly enhanced (P < .05). Consumption of SMT favourably affected leukocytes' p47phox expression and inflammatory cytokine and antioxidants levels in peripheral blood, which may help decrease oxidative stress and low-grade inflammation.

Effects of mate tea consumption on muscle strength and oxidative stress markers after eccentric exercise.

Dietary phytochemical supplementation may improve muscle recovery from exercise. In this study, we investigated the effect of mate tea (MT) consumption - a phenol-rich beverage - on muscle strength and oxidative stress biomarkers after eccentric exercise. In a randomised, cross-over design, twelve men were assigned to drink either MT or water (control; CON) for 11 d. On the 8th day, subjects performed three sets of twenty maximal eccentric elbow flexion exercises. Maximal isometric elbow flexion force was measured before and at 0, 24, 48 and 72 h after exercise. Blood samples were obtained before and at 24, 48 and 72 h after exercise and analysed for total phenolics, GSH, GSSG, GSH:GSSG ratio and lipid hydroperoxides (LOOH). After eccentric exercise, muscle strength was significantly reduced over time, regardless of treatments. However, MT improved the rate of strength recovery by 8·6 % on the 1st day after exercise (P<0·05). Plasma concentration of total phenolic compounds was higher in MT than in CON at all time points (P<0·05) but decreased significantly at 72 h after exercise in both trials (P<0·05). Blood levels of GSH were significantly decreased at 48 and 72 h after exercise in CON (P<0·05) but did not change over time in MT. No significant changes were observed for GSSG, GSH:GSSG ratio and LOOH levels. MT intake did not influence muscle strength at all time points assessed but hastened the strength recovery over 24 h after exercise. MT also favoured the concentration of blood antioxidant compounds.

Consumo alimentar de atletas: reflexões sobre recomendações nutricionais, hábitos alimentares e métodos para avaliação do gasto e consumo energéticos / Athletes' food intake: reflections on nutritional recommendations, food habits and methods for assessing energy expenditure and energy intake

O objetivo do artigo foi efetuar revisão sobre o consumo alimentar de atletas, enfatizando recomendações nutricionais, adequações dietéticas, comportamento alimentar e limitações dos métodos na avaliação dietética e estimativa do gasto energético nesta população. Foram analisados 30 artigos, publicados no período de 1984-2004, selecionados em bases eletrônicas de dados. O critério de inclusão dos artigos foi a abordagem sobre aspectos nutricionais relacionados ao exercício, recomendações de energia e nutrientes, bem como consumo alimentar de atletas. As recomendações de energia, macronutrientes e hidratação para atletas já estão bem determinadas, porém, pouco se conhece sobre as necessidades de vitaminas e minerais. Contudo, existe um consenso de que as necessidades de micronutrientes para a maioria desses indivíduos podem ser atendidas por uma dieta variada e equilibrada. Por outro lado, estudos indicam que a inadequação de energia e nutrientes ainda predomina em vários grupos atléticos, revelando a necessidade da reeducação nutricional. Diversos fatores inerentes à modalidade esportiva, tais como os esquemas de treinamento e as exigências relativas à imagem corporal, podem influenciar os hábitos alimentares do atleta. Portanto, a compreensão das relações entre o padrão de alimentação de atletas e os diversos fatores relacionados ao esporte são aspectos fundamentais para o estabelecimento de orientações nutricionais. A ocorrência de erros sistemáticos em pesquisas com atletas que empregam métodos que utilizam o auto-relato, ressalta a importância do rigor metodológico na aplicação desses instrumentos.

The purpose of this paper was to review the bibliography on athletes' food intake, emphasizing nutritional recommendations, dietary propriety and behavior, limitations of the methods for assessing food intake and estimated energy expenditure in this population. Thirty articles were analyzed, published from 1984 to 2004, selected from electronic databases. Articles that discussed nutritional aspects associated with exercise and those that made recommendations regarding energy, nutrient or food intake were included. Determinations for energy, macronutrient and liquid intake for athletes are already well established but little is known about their need of vitamins and minerals. However, there is a consensus that the micronutrient requirements for most of these individuals can be met by a varied and balanced diet. On the other hand, studies show that unbalanced energy and nutrient intakes still prevail among many athletic groups, revealing the need for dietary education. Many factors related to the type of sport such as training schemes and body image requirements may influence the athletes' dietary habits. Therefore, understanding the relationship between the athletes' eating patterns and the various patterns associated with the sport in question is essential to establish specific nutritional guidance. The occurrence of systematic errors in researches involving athletes that employ methods that rely on self reports emphasizes the importance of following a strict methodology when using these instruments.