β-Glucan, Immune Function, and Upper Respiratory Tract Infections in Athletes

• Published in: Medicine and science in sports and exercise Vol. 40; no. 8; pp. 1463 - 1471
• Main Authors: NIEMAN, David C, HENSON, Dru A, MCMAHON, Mary, WRIEDEN, Jenna L, DAVIS, J. Mark, MURPHY, E. Angela, GROSS, Sarah J, MCANULTY, Lisa S, DUMKE, Charles L
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 01-08-2008
• Subjects: beta-Glucans - administration & dosage; beta-Glucans - immunology; Biological and medical sciences; Dietary Supplements; Double-Blind Method; Exercise Test; Fundamental and applied biological sciences. Psychology; Humans; Immune System - drug effects; Male; Physical Exertion - physiology; Respiratory Tract Infections - drug therapy; Respiratory Tract Infections - epidemiology; Respiratory Tract Infections - immunology; Sports; Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports; Human; CYTOKINES; Upper respiratory tract; Respiratory disease; Cytokine; NATURAL KILLER CELLS; NEUTROPHILS; Respiratory system infection; Athlete; Natural killer cell; Sport; CYCLING; Neutrophil
• ISSN: 0195-9131; 1530-0315
• DOI: 10.1249/MSS.0b013e31817057c2

This study investigated the effects of oat beta-glucan (BG) supplementation on chronic resting immunity, exercise-induced changes in immune function, and self-reported upper respiratory tract infection (URTI) incidence in human endurance athletes.
Trained male cyclists were randomized to BG (N = 19) or placebo (P; N = 17) groups and under double-blind procedures received BG (5.6 g x d(-1)) or P beverage supplements for 2 wk before, during, and 1 d after a 3-d period in which subjects cycled for 3 h x d(-1) at approximately 57% maximal watts. URTI symptoms were monitored during BG supplementation and for 2 wk afterward. Blood samples were collected before and after 2 wk of supplementation (both samples, 8:00 a.m.), immediately after the 3-h exercise bout on day 3 (6:00 p.m.), and 14 h after exercise (8:00 a.m.) and were assayed for natural killer cell activity (NKCA), polymorphonuclear respiratory burst activity (PMN-RBA), phytohemagglutinin-stimulated lymphocyte proliferation (PHA-LP), plasma interleukin 6 (IL-6), IL-10, IL-1 receptor agonist (IL-1ra), and IL-8, and blood leukocyte IL-10, IL-8, and IL-1ra mRNA expression.
Chronic resting levels and exercise-induced changes in NKCA, PMN-RBA, PHA-LP, plasma cytokines, and blood leukocyte cytokine mRNA did not differ significantly between BG and P groups. URTI incidence during the 2-wk postexercise period did not differ significantly between groups.
An 18-d period of BG versus P ingestion did not alter chronic resting or exercise-induced changes in immune function or URTI incidence in cyclists during the 2-wk period after an intensified exercise.