HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Venkatraman, J. T. Articles by Pendergast, D. Search for Related Content PubMed PubMed Citation Articles by Venkatraman, J. T. Articles by Pendergast, D.

Effects of Dietary Fat and Endurance Exercise on Plasma Cortisol, Prostaglandin E₂, Interferon- and Lipid Peroxides in Runners

Department of Physical Therapy, Exercise and Nutrition Sciences (J.T.V., X.F.), State University of New York at Buffalo, Buffalo, New York
Department of Physiology (D.P.), State University of New York at Buffalo, Buffalo, New York

Address reprint requests to: Jaya T. Venkatraman, Ph.D., Associate Professor, Nutrition Program, Department of Physical Therapy, Exercise and Nutrition Sciences, State University of New York at Buffalo, 15 Farber Hall, Buffalo, NY 14214. E-mail: jtv{at}acsu.buffalo.edu

Objective: Exercise and the neuroendocrine and oxidative stress it elicits on immune function is modulated by dietary fat intake. The effects of increasing dietary fat on endurance exercise-induced alterations (80% of O_2max for 2 hours) in the plasma levels of cortisol and prostaglandin E₂ (PGE₂), interferon- (IFN-) and lipid peroxides were investigated. As higher levels of cortisol, PGE₂ and lipid peroxides could be immunosuppressive, the effects of different levels of dietary fat on these measures in runners were determined.

Methods: Healthy trained runners (males and females) consumed serially 15% fat diet (of daily energy), 30% fat diet and 40% fat diets for four weeks each. In the last week of each diet period the subjects ran to exhaustion at 80% of their O_2max and blood was drawn pre- and post-run. Cortisol, IFN-, PGE₂ and lipid peroxides were determined using standard techniques.

Results: Pre-exercise levels of plasma cortisol were elevated, IFN- was unchanged and PGE₂ and lipid peroxides decreased on the 40%F diet compared to 30%F and 15%F. Post-exercise levels of plasma cortisol (p < 0.004), PGE₂ (p < 0.0057) and lipid peroxide levels increased (p < 0.0001) after endurance exercise on all diets. The rates of increase of plasma cortisol levels during exercise were similar on all three diets. Although absolute cortisol levels were higher in the high fat group, the rate of increase of plasma cortisol level during exercise was similar on each diet. The dietary fat levels did not affect IFN-, however, PGE₂ and lipid peroxides decreased with increasing fat at baseline at 40%F level (p < 0.01; 30%F vs. 40%F: p < 0.002; 15%F vs. 40%F: p < 0.007).

Conclusions: Data from the present study suggest that higher levels of fat in the diet, up to 40%, increase endurance running time without adverse effects on plasma cortisol, IFN-, and lipid peroxide levels.

Key words: cortisol, diet fat, exercise, interferon-, prostaglandins, peroxides, runners

This article has been cited by other articles:

				S. Boullu-Ciocca, V. Achard, V. Tassistro, A. Dutour, and M. Grino Postnatal Programming of Glucocorticoid Metabolism in Rats Modulates High-Fat Diet-Induced Regulation of Visceral Adipose Tissue Glucocorticoid Exposure and Sensitivity and Adiponectin and Proinflammatory Adipokines Gene Expression in Adulthood Diabetes, March 1, 2008; 57(3): 669 - 677. [Abstract] [Full Text] [PDF]

				K. Meksawan, J. T. Venkatraman, A. B. Awad, and D. R. Pendergast Effect of Dietary Fat Intake and Exercise on Inflammatory Mediators of the Immune System in Sedentary Men and Women J. Am. Coll. Nutr., August 1, 2004; 23(4): 331 - 340. [Abstract] [Full Text] [PDF]