Document Detail


Antioxidants prevent health-promoting effects of physical exercise in humans.
MedLine Citation:
PMID:  19433800     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Exercise promotes longevity and ameliorates type 2 diabetes mellitus and insulin resistance. However, exercise also increases mitochondrial formation of presumably harmful reactive oxygen species (ROS). Antioxidants are widely used as supplements but whether they affect the health-promoting effects of exercise is unknown. We evaluated the effects of a combination of vitamin C (1000 mg/day) and vitamin E (400 IU/day) on insulin sensitivity as measured by glucose infusion rates (GIR) during a hyperinsulinemic, euglycemic clamp in previously untrained (n = 19) and pretrained (n = 20) healthy young men. Before and after a 4 week intervention of physical exercise, GIR was determined, and muscle biopsies for gene expression analyses as well as plasma samples were obtained to compare changes over baseline and potential influences of vitamins on exercise effects. Exercise increased parameters of insulin sensitivity (GIR and plasma adiponectin) only in the absence of antioxidants in both previously untrained (P < 0.001) and pretrained (P < 0.001) individuals. This was paralleled by increased expression of ROS-sensitive transcriptional regulators of insulin sensitivity and ROS defense capacity, peroxisome-proliferator-activated receptor gamma (PPARgamma), and PPARgamma coactivators PGC1alpha and PGC1beta only in the absence of antioxidants (P < 0.001 for all). Molecular mediators of endogenous ROS defense (superoxide dismutases 1 and 2; glutathione peroxidase) were also induced by exercise, and this effect too was blocked by antioxidant supplementation. Consistent with the concept of mitohormesis, exercise-induced oxidative stress ameliorates insulin resistance and causes an adaptive response promoting endogenous antioxidant defense capacity. Supplementation with antioxidants may preclude these health-promoting effects of exercise in humans.
Authors:
Michael Ristow; Kim Zarse; Andreas Oberbach; Nora Klöting; Marc Birringer; Michael Kiehntopf; Michael Stumvoll; C Ronald Kahn; Matthias Blüher
Publication Detail:
Type:  Controlled Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-05-11
Journal Detail:
Title:  Proceedings of the National Academy of Sciences of the United States of America     Volume:  106     ISSN:  1091-6490     ISO Abbreviation:  Proc. Natl. Acad. Sci. U.S.A.     Publication Date:  2009 May 
Date Detail:
Created Date:  2009-05-27     Completed Date:  2009-06-23     Revised Date:  2013-06-02    
Medline Journal Info:
Nlm Unique ID:  7505876     Medline TA:  Proc Natl Acad Sci U S A     Country:  United States    
Other Details:
Languages:  eng     Pagination:  8665-70     Citation Subset:  IM    
Affiliation:
Department of Human Nutrition, Institute of Nutrition, University of Jena, Jena D-07743, Germany. mristow@mristow.org
Data Bank Information
Bank Name/Acc. No.:
ClinicalTrials.gov/NCT00638560
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MeSH Terms
Descriptor/Qualifier:
Adult
Antioxidants / adverse effects*,  pharmacology*
Ascorbic Acid / adverse effects,  pharmacology
Biological Markers / blood
Exercise / physiology*
Health*
Humans
Insulin / blood,  physiology
Insulin Resistance / physiology
Male
Oxidative Stress / drug effects
Substrate Specificity
Time Factors
Vitamin E / adverse effects,  pharmacology
Chemical
Reg. No./Substance:
0/Antioxidants; 0/Biological Markers; 0/Insulin; 1406-18-4/Vitamin E; 50-81-7/Ascorbic Acid
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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