Effects of Oral Supplementation with Cystine and Theanine on the Immune Function of Athletes in Endurance Exercise: Randomized, Double-Blind, Placebo-Controlled Trial

Abstract

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.

Exercise-Induced Immunodepression in Endurance Athletes and Nutritional Intervention with Carbohydrate, Protein and Fat — What Is Possible, What Is Not?

“…[100,101] showed in two studies that supplementation with 700 mg cystine (dipeptid of cysteine) and 280 mg theanine (amino acid in green tea) several days prior and during a training camp, results in a significant decrease of post-exercise neutrophilia, attenuated lymphocytopenia, constant CRP levels but no differences in mucosal immunity compared to PLA. Very limited evidence exists on creatine supplementation and its effects on exercise immunity.…”

γ-Glutamylcysteine inhibits oxidative stress in human endothelial cells

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Efficacy of Gamma-glutamylcysteine (GGC) in Ischemia-reperfusion Injury

“…Therefore, we currently investigate a role of GGC as a cell-penetrating pepide by assessing its cellular uptake using an animal model. Administration of dipeptides influence atherosclerotic development in apo E-deficient mouse models (Matsui et al 2010) and immune responses and mRNA expression of GCS-HS in both humans and mice with compromised immune functions (Murakami et al 2009;. Oligopeptides inhibit TNFα-induced activation of NF-κB in human aortic endothelial cells (Ringseis et al 2009) and ROS formation by inducing the expression of antioxidant enzymes, superoxide dismutase (SOD) and heme oxygenase, in mice (White et al 2009).…”