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

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. 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. 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. 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. This clinical trial was registered at Clinical Research Information Service of Korea Centers for Disease Control and Prevention: KCT0004636.