Effects of L-Cystine and L-Theanine Supplementation on the Common Cold: A Randomized, Double-Blind, and Placebo-Controlled Trial

Table 5

Incidence and duration of laboratory-defined colds during the 5-week trial period.

	Cystine/Theanine group (𝑛=88)	Placebo group (𝑛=85)	𝑃-value
Laboratory-defined colds
– Number of volunteers (%)	10 (11.4)	23 (27.1)	.011^a
– Number of incidence	10	29	.002^b
– Cumulative days of incidence	18	59	.002^b
– Average duration (mean ± SE)	1.8±0.8	2.0±1.1	.883^c
Temperature, ≧37.0^∘C
– Number of volunteers (%)	16 (18.2)	28 (32.9)	.036^a
– Average duration (mean ± SE)	1.7±0.2	2.0±0.2	.182^c

aFisher’s exact test was used for comparisons between groups.
bPoisson regression analysis was used for comparisons between groups.
cThe 𝑡-test was used for comparisons between groups.