A double-masked study of the effects of ginseng on cognitive functions

The effects of a pure ginseng preparation on a variety of cognitive functions was compared with those of placebo in a double-masked, randomized, test-retest design. The subjects were healthy volunteers older than 40 years of age who were given the ginseng preparation or placebo for 8 to 9 weeks. Of the 112 subjects who completed the study, 55 received ginseng and 57 received placebo. The ginseng group showed a tendency to faster simple reactions and significantly better abstract thinking than the controls. However, there was no significant difference between the two groups in concentration, memory, or subjective experience.