Safety and efficacy of dietary supplement (gintonin-enriched fraction from ginseng) in subjective memory impairment: A randomized placebo-controlled trial

Background: Gintonin inhibits β-amyloid production, increases acetylcholine level in the brain, and promotes neurogenesis. We evaluated the efficacy of gintonin-enriched fraction (GEF) in improving the cognitive performance in subjective memory impairment. Methods: In this 8-week, randomized, assessor and participant blinded, placebo–controlled study, participants with subjective memory impairment but preserved cognitive function (Korean Mini-Mental State Examination [K-MMSE] score ≥23) were assigned to GEF 300mg/day or placebo. K-MMSE, Korean versions of the Alzheimer's disease assessment scale, color-word stroop test (K-CWST), clinical dementia rating, and Beck depression inventory-II were evaluated along with the safety profiles. The primary outcome was set as the change in the K-MMSE. Results: Seventy-six participants complete the study protocol. After 8 weeks, there was no inter-group difference in the primary or secondary outcome score changes. However, GEF group showed an improvement in the K-MMSE scores (P= 0.026), and in the number of correct answers in both word reading (P= 0.008) and color reading (P= 0.005) of K-CWST, although only the improvement in the K-CWST scores were higher than the minimum clinically important difference. The frequency of adverse events was comparable between the groups and all were of mild severity. Conclusion: GEF is safe but might not be effective in treating subjective memory impairment within the current study setting. However, GEF showed a trend of improving the global cognition and the frontal executive function. Further large-sized studies with longer follow-up period are warranted. Clinical trial registration: This clinical trial was registered at Clinical Research Information Service of Korea Centers for Disease Control and Prevention: KCT0004636