Effects of oral supplementation with cystine and theanine on the immune function of athletes in endurance exercise: randomized, double-blind, placebo-controlled trial.
Athletes become increasingly susceptible to infection with intense training that results in immune suppression. The immune state was investigated after administering cystine/theanine (CT), which has been reported to have an immune reinforcement effect, to athletes before training involving a prolonged period of intense exercise. Fifteen long-distance runners were each allocated to the CT or placebo group, and the test food was ingested for 10 d prior to the start of training. Clinical examinations were performed before and after the training. The results indicate a significant increase in the high-sensitivity C-reactive protein (hs-CRP) and neutrophil count in the blood, as well as a decreasing tendency for lymphocytes in the placebo group, but not the CT group. These observations suggest that the ingestion of CT contributed to suppressing the change in inflammatory response, prevented a decrease in the immune function, and prevented infection and reduced symptoms when infected associated with continuous intense exercise.
Murakami
Shigeki
S
Department of Sports Science, School of Health and Sports Science, Juntendo University, Chiba 270-1695, Japan.
Kurihara
Shigekazu
S
Koikawa
Natsue
N
Nakamura
Akira
A
Aoki
Kazuhiro
K
Yosigi
Hiroshi
H
Sawaki
Keisuke
K
Ohtani
Masaru
M
D000284:Administration, Oral; D015415:Biomarkers / Q000378:metabolism; D003553:Cystine / Q000008:administration & dosage* / Q000494:pharmacology*; D019587:Dietary Supplements; D004311:Double-Blind Method; D005971:Glutamates / Q000008:administration & dosage* / Q000494:pharmacology*; D006801:Humans; D008297:Male; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology; D010807:Physical Endurance / Q000187:drug effects* / Q000276:immunology*; D012420:Running / Q000502:physiology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D055815:Young Adult
D015415:Biomarkers; D005971:Glutamates; D003553:Cystine; C026166:theanine