Efficacy of Ethanolic Extract of var. Stems for Improving Cognitive Function in Elderly Subjects 55-85 Years of Age: A Randomized, Double-Blind, Placebo-Controlled Study.

Many natural compounds have been reported to improve cognitive function in cell- and animal-based studies. In this clinical trial, we evaluated the efficacy of ethanolic extract of var. stem for improving cognitive function using a randomized, double-blind, placebo-controlled trial ( = 81) in aged people. After 12 weeks of administration of OFE (a mixture of ethanolic extract of var. stem and dextrin) or placebo, the effect on cognitive function was assessed. Overall, OFE did not show a significant difference from the placebo in terms of efficacy. However, the cognitive function significantly improved in the OFE group compared with the placebo group in the subgroup ≤70 years of age, which means that the effect of OFE administration exhibits an age-dependent effect. In addition, the safety of OFE was confirmed by analyzing blood test results, vital signs, and electrocardiograms. In conclusion, OFE administration in participants ≤70 years of age shows a positive effect on overall cognitive function. The trial was registered on CRIS (the Clinical Research Information Service), administered by the Korea Centers for Disease Control & Prevention (Registration Number: KCT0003766; URL: https://cris.nih.go.kr/cris/en/search/search_result_st01.jsp?seq=12957).