Effects of Cordyceps militaris supplementation on the immune response and upper respiratory infection in healthy adults: a randomized, double-blind, placebo-controlled study / 한국영양학회지

ABSTRACT

PURPOSE: Upper respiratory tract infections are major causes of the common cold throughout the world. Cordyceps militaris (C. militaris) is a well-known functional food for its anti-fatigue and immunomodulating activities. On the other hand, there are no reports on the protective effect against upper respiratory tract infections (URI). This study was a 12 week randomized, double-blind, and placebo-controlled trial in healthy volunteers. METHODS: A total of 100 subjects 20 ~ 70 years of age with a history of at least two colds in the year were enrolled in the study. The participants were required to record any adverse events and rate any cold-related incidents in a diary during the investigation period. The efficacy end point was the symptoms and incidence of URI, and changes in cytokines, IgA and natural killer (NK) cell activity. RESULTS: The Cordyceps militaris group over 12 weeks showed no significant impact on the incidence and symptomatology of URI compared to the placebo group. On the other hand, the experimental group showed significantly higher NK cell activity (p = 0.047) and IgA level (p = 0.035) compared to the placebo group. The NK-cell activity and IgA level were increased significantly by Cordyceps militaris over 12 weeks. CONCLUSION: The results suggest the possible beneficial immunomodulating effects, but the protective effects on URI could not be demonstrated under these conditions. Additional research will be needed to determine the efficacy and mechanisms of Cordyceps militaris function.