Efficacy and safety of CAEC (Canavalia gladiata arctium lappa extract complex) on immune function enhancement: An 8 week, randomised, double-blind, placebo-controlled clinical trial

[Display omitted] •CAEC enhanced immune function by stimulating NK cell activity and IL-10 expression.•CAEC significantly increased NK cell activity at E:T = 25:1 and 50:1 after 8 weeks.•CAEC significantly increased the level of IL-10 after 8 weeks.•CAEC will be able to serve as a functional food for stimulating immunity. The aim of this study was to evaluate the efficacy and safety of CAEC (Canavalia gladiata arctium lappa extract complex) in adults with white blood cells between 3 and 8 × 103 cells/µL by assessing natural killer (NK) cell activity and immune-related biomarkers. Overall, 100 participants (CAEC group = 50, placebo group = 50) were randomised, and administered CAEC or placebo once daily for 8 weeks, with an evaluation visit performed every 4 weeks. NK cell activity, the primary outcome, significantly increased in CAEC when compared with the placebo at effector-to-target (E:T) ratios of 25:1 and 50:1 after 8 weeks. Compared with the placebo group, IL-10 demonstrated significant differences at week 8 in the CAEC group. Our findings demonstrate that CAEC is safe and enhances immune function by stimulating NK cell activity through IL-10 expression. Hence, we anticipate that CAEC can be developed as a functional food for stimulating immunity.