Improvement of Cognitive Functions by Taking Supplement Containing Panax ginseng―A Randomized, Placebo—controlled, Double—blind, Clinical Study―

Background　Panax ginseng is one of the most popular herbal medicine since ancient time. Generally, it has been used as a nutritional supplement or an analeptic. In addition to these benefits, ginseng is also considered to affect the nervous system and improve the cognitive functions. However, its scientific evidence for the cognitive function of healthy subjects has been still uncertain. Methods　In this study, we performed a randomized, double-blind, placebo-controlled parallel-group comparative study to evaluate the improvement of the cognitive functions by taking supplements made from Panax ginseng grown in Korea for 6 weeks. The changes in the cognitive functions of 30 healthy subjects over 60 years of age were evaluated by three cognitive tests: Benton visual retention test, modified Stroop test Ⅱ, and mini mental state examination （MMSE）. Results　Thirty subjects were allocated into two groups of 15 subjects. Each subject took either 2 packages of ginseng supplements or placebo in a day for 6 weeks. Two ginseng packages contain 7.8 mg of ginsenosides. Statistically significant improvements in the ginseng group were found by Benton visual retention test, however, no significant changes were observed in the placebo group. Mild cognitive improvements were also found only in the ginseng group by the modified Stroop test Ⅱ; while no significant changes were detected in the both groups by MMSE. Conclusion　These results suggest that the daily intake of the supplement of Panax ginseng has beneficial effects especially in the visual cognitive function and the selective attention. We speculate that the ginseng supplement has great possibilities to improve our health-related quality of life（QOL）.