Exercise-induced changes in immune function: effects of zinc supplementation.
To examine the effect of zinc (Zn) supplementation on exercise-induced changes in immune function, five male runners were randomly assigned in a double-blind crossover design to take a supplement (S; 25 mg of Zn and 1.5 mg of copper) or placebo (P) twice daily for 6 days. On morning 4 of each phase, 1 h after taking S or P, subjects ran on a treadmill at 70-75% of maximal oxygen uptake until exhaustion (approximately 2 h). Blood samples were obtained before (Pre), immediately after (Post), and 1 (Rec1) and 2 (Rec2) days after the run. [3H]thymidine incorporation by mitogen-treated mononuclear cell cultures was significantly lower (P < 0.05) Post than Pre, Rec1, or Rec2 for both S and P. Respiratory burst activity of isolated neutrophils was enhanced after exercise with P but not with S (P: Pre 12.0 +/- 1.1 vs. Post 17.6 +/- 2.3 nmol O2-/10(6) cells; S: Pre 11.7 +/- 0.3 vs. Post 12.1 +/- 1.2 nmol O2-/10(6) cells). Thus supplemental Zn blocked the exercise-induced increase in reactive oxygen species. Whether this antioxidant effect of Zn will benefit individuals exposed to chronic physical stress remains to be determined.
Singh
A
A
Department of Military and Emergency Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814.
Failla
M L
ML
Deuster
P A
PA
D000328:Adult; D001772:Blood Cell Count; D003300:Copper / Q000097:blood; D004032:Diet; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007109:Immunity / Q000187:drug effects* / Q000502:physiology*; D007773:Lactates / Q000097:blood; D019344:Lactic Acid; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000502:physiology; D008297:Male; D008934:Mitogens; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology / Q000502:physiology; D016897:Respiratory Burst / Q000502:physiology; D013481:Superoxides / Q000378:metabolism; D015032:Zinc / Q000097:blood / Q000494:pharmacology* / Q000652:urine
D007773:Lactates; D008934:Mitogens; D013481:Superoxides; D019344:Lactic Acid; D003300:Copper; D015032:Zinc; D006854:Hydrocortisone