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  • Author: Josep A. Tur x
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Antoni Sureda, Miguel D. Ferrer, Antonia Mestre, Josep A. Tur and Antoni Pons

The authors studied the effects of antioxidant diet supplementation with an almond-based beverage on neutrophil antioxidants, nitrite, and protein oxidative alterations after exercise. Fourteen trained male amateur runners were randomly assigned in a double-blind fashion to receive antioxidant supplementation (152 mg/d vitamin C and 50 mg/d vitamin E) or placebo using an almond-based beverage for 1 mo and participated in a half-marathon race. Blood samples were taken before and after the half-marathon and after 3 hr recovery. Supplementation significantly increased basal neutrophil vitamin C compared with placebo (p < .05). Exercise increased neutrophil vitamin E levels in the supplemented group and decreased vitamin C in both groups after recovery (p < .05). Neutrophil catalase and glutathione peroxidase gene expression and nitrite levels were significantly increased as result of exercise (p < .05). Nitrotyrosine and protein carbonyl derivates increased only in the placebo group after exercise (p < .05), and these values remained high at recovery. No significant differences were evidenced in caspase-3 activity and DNA damage. Antioxidant supplementation with vitamins C and E reduced the exercise-induced oxidation of proteins in neutrophils, without altering the antioxidant adaptive response, as evidenced by the increased catalase and glutathione peroxidase gene expression.

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Antoni Aguiló, Pere Tauler, Emilia Fuentespina, Gerardo Villa, Alfredo Córdova, Josep A. Tur and Antoni Pons

Objective:

The aim of this work was to check the effects of antioxidant supplementation (vitamins E and C, and β-carotene) on the basal iron status of athletes prior to and following their training and competition season (3 months).

Design:

Eighteen amateur trained male athletes were randomly distributed in 2 groups: placebo (lactose) and antioxidant supplemented (vitamin E, 500 mg/d; vitamin C, 1 g/d; and β-carotene, 30 mg/d). The study was double blind. Hematological parameters, dietary intake, physical activity intensity, antioxidant status (GSH/GSSG ratio), and basal iron status (serum iron, transferrin, ferritin, and iron saturation index) were determined before and after the intervention trials.

Results:

Exercise decreased antioxidant defenses in the placebo group but not in the antioxidant-supplemented group. No changes were found in the number of erythrocytes, hematocrit, or hemoglobin concentration, or in values of serum iron parameters, after taking the antioxidant cocktail for 3 months, in spite of the exercise completed. The placebo group showed a high oxidative stress index, and decreases in serum iron (24%) and iron saturation index (28%), which can neither be attributed to aspects of the athletes’ usual diet, nor to hemoconcentration.

Conclusions:

Antioxidant supplementation prevents the decrease of serum iron and the iron saturation index, and a link between iron metabolism and oxidative stress may also be suggested.