1.
Effect of a special carbohydrate-protein bar and tomato juice supplementation on oxidative stress markers and vascular endothelial dynamics in ultra-marathon runners.
Samaras, A, Tsarouhas, K, Paschalidis, E, Giamouzis, G, Triposkiadis, F, Tsitsimpikou, C, Becker, AT, Goutzourelas, N, Kouretas, D
Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association. 2014;:231-6
Abstract
It is well established that exercise induces excessive production of reactive species leading to oxidative stress, which has been implicated in oxidative damage of macromolecules, immune dysfunction, muscle damage and fatigue. The present study examined the effect of supplementation of ultra-marathon runners for a two-months-period with a special whey protein bar containing carbohydrates and protein in a specific ratio (1:1) (N=16), prepared using as starting material the by-products of cheese manufacturing, and supplementation with commercially available tomato juice (N=15). Thiobarbituric-acid reactive substances and protein carbonyls were significantly decreased in both supplementation groups, while a pronounced increased in reduced glutathione was observed in the protein bar group. Total anti-oxidant activity remained unchanged in both groups. Flow-mediated dilatation, used as an estimate of endothelial function, was increased in both groups, with a significant rise observed only in the tomato juice administration group. In conclusion, supplementation of ultra marathon runners for a two-months-period with a special protein bar and tomato juice significantly improved the oxidative status of the subjects, while tomato juice also improved vascular endothelial function in these athletes.
2.
Yacon effects in immune response and nutritional status of iron and zinc in preschool children.
Vaz-Tostes, Md, Viana, ML, Grancieri, M, Luz, TC, Paula, Hd, Pedrosa, RG, Costa, NM
Nutrition (Burbank, Los Angeles County, Calif.). 2014;(6):666-72
Abstract
OBJECTIVE The aim of this study was to evaluate the effect of yacon flour on iron and zinc nutritional status and immune response biomarkers in preschool children. METHODS Preschool children ages 2 to 5 y were selected from two nurseries and were placed into a control group (n = 58) or a yacon group (n = 59). The yacon group received yacon flour in preparations for 18 wk at a quantity to provide 0.14 g of fructooligosaccharides/kg of body weight daily. Anthropometric parameters were measured before and after the intervention and dietary intake was measured during the intervention. To assess iron and zinc status, erythrograms, serum iron, ferritin, and plasma, and erythrocyte zinc were evaluated. Systemic immune response was assessed by the biomarkers interleukin IL-4, IL-10, IL-6, and tumor necrosis factor-alfa (TNF-α). Intestinal immune response was analyzed by secretory IgA (sIgA) levels before and after the intervention. Statistical significance was evaluated using the paired t test (α = 5%). RESULTS Before and after the study, the children presented a high prevalence of overweight and an inadequate dietary intake of zinc and fiber. The yacon group presented with lower hemoglobin, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration at the end of the study (P < 0.05). Erythrocyte zinc was reduced in both groups at the end of the study (P < 0.05). Yacon intake increased the serum levels of IL-4 and fecal sIgA (P < 0.05). The control group had lower serum TNF-α after the study period (P < 0.05). CONCLUSION Yacon improved intestinal immune response but demonstrated no effect on the nutritional status of iron and zinc in preschool children.
3.
Plasma zinc and immune markers in runners in response to a moderate increase in training volume.
Peake, JM, Gerrard, DF, Griffin, JF
International journal of sports medicine. 2003;(3):212-6
Abstract
Changes in plasma zinc concentration and markers of immune function were examined in a group of 10 male runners (n = 10) following a moderate increase in training over four weeks. Seven sedentary males acted as controls. Fasting blood samples were taken at rest, before (T0) and after (T4) four weeks of increased (+ 16 %) training and after two weeks of reduced (-31 %) training (T6). Blood was analysed for plasma zinc concentration, differential leucocyte counts, lymphocyte subpopulations and lymphocyte proliferation using incorporation of 3H-thymidine. The runners increased their training volume by 16 % over the four weeks. When compared with the nonathletes, the runners had lower concentrations of plasma zinc (p = 0.012), CD3 + (p = 0.042) and CD19 + lymphocytes (p = 0.010) over the four weeks. Lymphocyte proliferation in response to Concanavalin A stimulation was greater in the runners (p = 0.0090). Plasma zinc concentration and immune markers remained constant during the study. Plasma zinc concentration correlated with total leucocyte counts in the athletes at T6 (r = -0.72, p < 0.05) and with Pokeweed mitogen stimulation in the nonathletes at T6 (r = -0.92, p < 0.05). Therefore, athletes are unlikely to benefit from zinc supplementation during periods of moderately increased training volume.