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.
Department of Sports Science, School of Health and Sports Science, Juntendo University, Chiba 270-1695, Japan.
Shigeki
S
Murakami
Shigekazu
S
Kurihara
Natsue
N
Koikawa
Akira
A
Nakamura
Kazuhiro
K
Aoki
Hiroshi
H
Yosigi
Keisuke
K
Sawaki
Masaru
M
Ohtani
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