OBJECTIVE: To assess the feasibility, safety, and efficacy of ginkgo biloba extract (GBE) on delaying the progression to cognitive impairment in normal elderly aged 85 and older. METHODS: Randomized, placebo-controlled, double-blind, 42-month pilot study with 118 cognitively intact subjects randomized to standardized GBE or placebo. Kaplan-Meier estimation, Cox proportional hazard, and random-effects models were used to compare the risk of progression from Clinical Dementia Rating (CDR) = 0 to CDR = 0.5 and decline in episodic memory function between GBE and placebo groups. RESULTS: In the intention-to-treat analysis, there was no reduced risk of progression to CDR = 0.5 (log-rank test, p = 0.06) among the GBE group. There was no less of a decline in memory function among the GBE group (p = 0.05). In the secondary analysis, where we controlled the medication adherence level, the GBE group had a lower risk of progression from CDR = 0 to CDR = 0.5 (HR = 0.33, p = 0.02), and a smaller decline in memory scores (p = 0.04). There were more ischemic strokes and TIAs in the GBE group (p = 0.01). CONCLUSIONS: In unadjusted analyses, ginkgo biloba extract (GBE) neither altered the risk of progression from normal to Clinical Dementia Rating (CDR) = 0.5, nor protected against a decline in memory function. Secondary analysis taking into account medication adherence showed a protective effect of GBE on the progression to CDR = 0.5 and memory decline. Results of larger prevention trials taking into account medication adherence may clarify the effectiveness of GBE. More stroke and TIA cases observed among the GBE group requires further study to confirm. (PsycInfo Database Record (c) 2024 APA, all rights reserved)
[Correction Notice: An erratum for this article was reported in Vol 300(23) of <i>JAMA: Journal of the American Medical Association</i> (see record [rid]2008-19064-007[/rid]). In the article, sales of <i>G. biloba</i> in the United States needed clarification. On page 2254 in the first column, the first full sentence should have read as follows: “In 1999 (when the study was initiated), total US sales of <i>G. biloba</i> exceeded $249 million.⁵”] CONTEXT: <i>Ginkgo biloba</i> is widely used for its potential effects on memory and cognition. To date, adequately powered clinical trials testing the effect of <i>G biloba</i> on dementia incidence are lacking. OBJECTIVE: To determine effectiveness of <i>G biloba</i> vs placebo in reducing the incidence of all-cause dementia and Alzheimer disease (AD) in elderly individuals with normal cognition and those with mild cognitive impairment (MCI). Design, Setting, and Participants: Randomized, double-blind, placebo-controlled clinical trial conducted in 5 academic medical centers in the United States between 2000 and 2008 with a median follow-up of 6.1 years. Three thousand sixty-nine community volunteers aged 75 years or older with normal cognition (n = 2587) or MCI (n = 482) at study entry were assessed every 6 months for incident dementia. Intervention: Twice-daily dose of 120-mg extract of <i>G biloba</i> (n = 1545) or placebo (n = 1524). MAIN OUTCOME MEASURES: Incident dementia and AD determined by expert panel consensus. RESULTS: Five hundred twenty-three individuals developed dementia (246 receiving placebo and 277 receiving <i>G biloba</i>) with 92% of the dementia cases classified as possible or probable AD, or AD with evidence of vascular disease of the brain. Rates of dropout and loss to follow-up were low (6.3%), and the adverse effect profiles were similar for both groups. The overall dementia rate was 3.3 per 100 person years in participants assigned to <i>G biloba</i> and 2.9 per 100 person-years in the placebo group. The hazard ratio (HR) for <i>G biloba</i> compared with placebo for all cause dementia was 1.12 (95% confidence interval [CI], 0.94-1.33; P = .21) and for AD, 1.16 (95% CI, 0.97-1.39; P = .11). <i>G biloba</i> also had no effect on the rate of progression to dementia in participants with MCI (HR, 1.13; 95% CI, 0.85-1.50; P = .39). CONCLUSIONS: In this study, <i>G biloba</i> at 120 mg twice a day was not effective in reducing either the overall incidence rate of dementia or AD incidence in elderly individuals with normal cognition or those with MCI. (PsycInfo Database Record (c) 2024 APA, all rights reserved)