by Dr. Leo Galland
While exercise has many benefits, the physical strain of strenuous exercise tends to depress the immune system, which can be a problem for athletes.
Recent research done in Japan indicates that the amino acids cysteine and theanine could help boost immunity and prevent infections for people engaging in intense physical activity.
A study of endurance athletes at Juntendo University outside of Tokyo found that ten days of distance running (about 7 to 8 miles a day) resulted in an increase in blood levels of C-reactive protein, a marker of inflammation, and a decrease in the blood lymphocyte count, a marker of immunity.
In a double-blind, placebo-controlled trial a group of athletes was given a combination of two amino acids, cysteine (700 milligrams per day) and theanine (280 milligrams per day).
The amino acids cysteine and theanine helped to prevent exercised-induced inflammation, maintain immune function, prevent infections and reduce symptoms of infections for the athletes in this trial.
Reference and Abstract:
Biosci Biotechnol Biochem. 2009 Apr 23;73(4):817-21. Effects of oral supplementation with cysteine and theanine on the immune function of athletes in endurance exercise: randomized, double-blind, placebo-controlled trial.
Murakami S, Kurihara S, Koikawa N, Nakamura A, Aoki K, Yosigi H, Sawaki K, Ohtani M. Department of Sports Science, School of Health and Sports Science, Juntendo University, Chiba 270-1695, Japan.
Athletes become increasingly susceptible to infection with intense training that results in immune suppression. The immune state was investigated after administering cysteine/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