Antioxidant diet supplementation influences blood iron status in endurance athletes.
OBJECTIVE
The aim of this work was to check the effects of antioxidant supplementation (vitamins E and C, and beta-carotene) on the basal iron status of athletes prior to and following their training and competition season (3 months).


METHODS
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 beta -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.
Aguilo
Antoni
A
Community Nutrition and Oxidative Stress Research Group at the University of the Balearic Islands, Palma de Mallorca, Spain.
Tauler
Pere
P
Fuentespina
Emilia
E
Villa
Gerardo
G
Cordova
Alfredo
A
Tur
Josep A
JA
Pons
Antoni
A
D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage*; D001205:Ascorbic Acid / Q000008:administration & dosage*; D019587:Dietary Supplements; D004311:Double-Blind Method; D005293:Ferritins / Q000097:blood / Q000378:metabolism; D006801:Humans; D007501:Iron / Q000097:blood*; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D010807:Physical Endurance; D014168:Transferrin / Q000378:metabolism; D014810:Vitamin E / Q000008:administration & dosage*; D019207:beta Carotene / Q000008:administration & dosage*
D000975:Antioxidants; D014168:Transferrin; D019207:beta Carotene; D014810:Vitamin E; D005293:Ferritins; D007501:Iron; D001205:Ascorbic Acid